Updated on 2021/09/24

写真a

 
MURAMATSU Shogo
 
Organization
Academic Assembly Institute of Science and Technology JOUHOU DENSHI KOUGAKU KEIRETU Professor
Faculty of Engineering Department of Engineering Professor
Title
Professor
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Degree

  • 博士(工学) ( 1998.11   東京都立大学 )

Research Interests

  • Embedded vision system

  • Filter banks

  • Sparse modeling

  • Multidimensional signal processing

  • Image restoration

  • Cyber-physical system

Research Areas

  • Social Infrastructure (Civil Engineering, Architecture, Disaster Prevention) / Disaster prevention engineering

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Communication and network engineering  / Signal processing

  • Informatics / Perceptual information processing  / Visual information processing

Research History (researchmap)

  • Niigata University   College of Creative Studies   Professor

    2021.4

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  • Niigata University   Faculty of Engineering   Professor

    2019.4

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  • 情報通信研究機構   ワイヤレスネットワーク総合研究センター   招へい専門員

    2018.6 - 2019.3

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  • Niigata University   Graduate School of Science and Technology Electrical and Information Engineering   Associate Professor

    2008.4 - 2019.3

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  • Niigata University   Faculty of Engineering Department of Electrical and Electronic Engineering   Associate Professor

    2004.4 - 2019.3

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  • University of Florence   Dept. of Information Engineering   Visiting Researcher

    2003.10 - 2004.9

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  • 新潟大学   工学部 電気電子工学科   Associate Professor (as old post name)

    2001.2 - 2004.3

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  • Niigata University   Faculty of Engineering   Research Assistant

    1999.1 - 2001.1

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  • Tokyo Metropolitan University   工学研究科 電気工学専攻   Research Assistant

    1997.4 - 1999.10

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  • Tokyo Metropolitan University   工学部 電子・情報工学科   Research Assistant

    1997.1 - 1997.3

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Research History

  • Niigata University   Faculty of Engineering Department of Engineering   Professor

    2019.4

  • Niigata University   Faculty of Engineering Department of Engineering   Associate Professor

    2017.4 - 2019.3

  • Niigata University   Graduate School of Science and Technology Electrical and Information Engineering   Associate Professor

    2010.4 - 2019.3

  • Niigata University   Graduate School of Science and Technology Electrical and Information Engineering   Associate Professor

    2010.4 - 2019.3

  • Niigata University   Faculty of Engineering Department of Electrical and Electronic Engineering   Associate Professor

    2004.4 - 2017.3

  • Niigata University   Abolition organization Communication Systems   Associate Professor (as old post name)

    2001.2 - 2004.3

  • Niigata University   Faculty of Engineering   Research Assistant

    1999.1 - 2001.1

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Education

  • Tokyo Metropolitan University

    1995.4 - 1996.12

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  • Tokyo Metropolitan University

    1993.4 - 1995.3

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  • Tokyo Metropolitan University   Faculty of Engineering   Department of Electrical Engineering

    1991.4 - 1993.3

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  • Tokyo National College of Technology   Department of Electronic Engineering

    1986.4 - 1991.3

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Professional Memberships

Committee Memberships

  • ITC-CSCC 2021   General Co-chair  

    2021.6   

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  • 電子情報通信学会 基礎・境界ソサイエティ   副会長(システムと信号処理サブソサイエティ サブソサイエティ長)  

    2020.6 - 2021.5   

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  • 映像情報メディア学会メディア工学研究委員会   副委員長  

    2020.5   

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  • APSIPA   Distinguished Lecturer  

    2020 - 2021   

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    Committee type:Academic society

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  • IEEE Transactions on Signal Processing   Associate Editor  

    2019.9   

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    Committee type:Academic society

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  • 電子情報通信学会 基礎・境界ソサイエティ 信号処理研究専門委員会   委員長  

    2018.6 - 2019.5   

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  • 第32回信号処理シンポジウム   TPC委員長  

    2017.11   

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  • 電子情報通信学会 基礎・境界ソサイエティ 和/英文論文誌A編集委員会   分野編集幹事(Image, Vision)  

    2017.6 - 2019.5   

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  • IEEE Signal Processing Society Tokyo Joint Chapter   Treasurer  

    2017.1 - 2018.12   

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    Committee type:Academic society

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  • IWAIT 2022   Program Co-chair  

    2022.1   

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  • 13th APSIPA ASC   Special Session Co-chair  

    2021.12   

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  • 電子情報通信学会   功績賞・業績賞委員会委員  

    2020.9 - 2021.2   

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  • 電子情報通信学会 基礎・境界ソサイエティ システムと信号処理サブソサイエティ   副サブソサイエティ長  

    2019.6 - 2020.5   

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    Committee type:Academic society

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  • IEEE Shin-etsu Section   Student Activities Chair  

    2019.1   

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  • APSIPA Image, Video, and Multimedia (IVM) Technical Committee   Member  

    2018   

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  • ITC-CSCC 2017   TPC Co-chair  

    2017.7   

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  • 電子情報通信学会 基礎・境界ソサイエティ 信号処理研究専門委員会   副委員長  

    2016.6 - 2018.6   

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  • 電子情報通信学会 信越支部   庶務幹事  

    2010.5 - 2012.5   

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  • 映像情報メディア学会 メディア工学研究会 サマーセミナー2010   企画委員長  

    2010   

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  • 電子情報通信学会 基礎・境界ソサイエティ   英文論文誌A編集委員会委員  

    2009.5 - 2013.5   

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  • 電子情報通信学会   大会委員  

    2008.12 - 2009.11   

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  • 電子情報通信学会 知識ベース1群9編   編集幹事  

    2008.1 - 2018.12   

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  • 新潟市粗大ごみ受付センター構築及び開設準備委託業務業者選定委員会   委員  

    2007.7 - 2007.9   

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    Committee type:Municipal

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  • 映像情報メディア学会 メディア工学研究会   幹事  

    2007.5   

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    Committee type:Academic society

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  • 電子情報通信学会   会誌編集委員会委員  

    2007.5 - 2009.4   

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  • International Workshop on Advanced Image Technology 2006   Securetary  

    2006   

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  • 画像符号化シンポジウム   運営委員  

    2006   

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  • 電子情報通信学会 回路とシステム軽井沢ワークショップ   論文担当幹事  

    2004.10 - 2005.9   

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  • 電子情報通信学会 基礎・境界ソサイエティ   論文誌査読員  

    2003.1   

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  • 電子情報通信学会   大会委員  

    2002.12 - 2003.11   

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  • 電子情報通信学会 回路とシステム軽井沢ワークショップ   総務担当幹事  

    2001.10 - 2002.9   

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  • 電子情報通信学会 基礎・境界ソサイエティ 回路とシステム研究専門委員会   幹事補佐  

    2000.5 - 2002.5   

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Papers

  • Multidimensional Nonseparable Oversampled Lapped Transforms: Theory and Design Reviewed

    Shogo Muramatsu, Kosuke Furuya, Naotaka Yuki

    IEEE TRANSACTIONS ON SIGNAL PROCESSING   65 ( 5 )   1251 - 1264   2017.3

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    This paper extends the theory of the one-dimensional oversampled linear-phase perfect reconstruction filter banks (OLPPRFBs) developed by Gan et al. to multidimensional (MD) cases and proposes MD nonseparable oversampled lapped transforms (NSOLTs). NSOLTs allow us to achieve an overcomplete analysis-synthesis system with nonseparable, symmetric, realvalued, overlapping, and compact-supported filters. The proposed systems are based on lattice structures and the redundancy is flexibly controlled by the number of channels and downsampling ratio. The proposed structure is shown to be capable of constructing Parseval tight frames in any number of dimensions. The number of design parameters are examined under the Parseval tight frame constraint. In order to design NSOLTs specified for sparse approximation of image or volume data, an example-based design procedure is introduced. The effectiveness of this method is verified by examining design samples and evaluating their sparse approximation performance using the iterative hard thresholding algorithm for a natural image and MRI volume data patch.

    DOI: 10.1109/TSP.2016.2633240

    Web of Science

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  • Redundant Transforms and Its Application to Image Restoration Invited Reviewed

    MURAMATSU Shogo

    NIHON GAZO GAKKAISHI   53 ( 4 )   290 - 300   2014.8

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    This article reviews redundant transforms for sparse representation of images. The term “sparse representation” here denotes a way of signal representation by a linear combination of a small number of vectors, sequences or functions. This representation is used for signal modeling and finds a lot of applications such as signal estimation, restoration and feature extraction. In order to obtain a good sparse representation, it is essential to choose a signal transform appropriately. In this article, redundancy is firstly explained as an effective property of transforms for sparse representation. Then, some problem settings of sparse representation are introduced and their solvers are overviewed. Next, redundant transforms are shown to be successfully applied to image restoration problems. Furthermore, desired properties of transforms for image processing are summarized, and then dictionary learning methods are introduced as a design technique of redundant transforms. Finally, trends of related works are summarized as concluding remarks.

    DOI: 10.11370/isj.53.290

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  • Directional Lapped Orthogonal Transform: Theory and Design Reviewed

    Shogo Muramatsu, Dandan Han, Tomoya Kobayashi, Hisakazu Kikuchi

    IEEE TRANSACTIONS ON IMAGE PROCESSING   21 ( 5 )   2434 - 2448   2012.5

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    This paper proposes a directional design method of 2-D nonseparable linear-phase paraunitary filter banks. The proposed method is based on a lattice structure consisting of the 2-D separable DCT block and nonseparable support extension processes. Because of the nonseparability, the bases are allowed to be directional with the critically fixed subsampling, overlapping, orthogonal, symmetric, real-valued, and compact support properties. First, a novel vanishing moment (VM) condition is introduced as a suitable directional constraint, where the moment is referred to as the trend VM. The condition forces wavelet filters, i.e., high-pass and bandpass filters, to annihilate trend-surface components. Second, some theoretical properties of TVMs are discussed for general 2-D paraunitary systems, and then, the properties are applied to the lattice parameters. In order to verify the significance, several design examples are shown, the trend-surface annihilation properties are numerically confirmed, and the denoising capability is evaluated for images through shrinkage. It is shown that our proposed transforms yield perceptually preferable results.

    DOI: 10.1109/TIP.2011.2182055

    Web of Science

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  • Boundary Operation of 2-D Nonseparable Linear-Phase Paraunitary Filter Banks Reviewed

    Shogo Muramatsu, Tomoya Kobayashi, Minoru Hiki, Hisakazu Kikuchi

    IEEE TRANSACTIONS ON IMAGE PROCESSING   21 ( 4 )   2314 - 2318   2012.4

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    This paper proposes a boundary operation technique of 2-D nonseparable linear-phase paraunitary filter banks (NS-LPPUFBs) for size limitation. The proposed technique is based on a lattice structure consisting of the 2-D separable block discrete cosine transform and nonseparable support-extension processes. The bases are allowed to be anisotropic with the fixed critically subsampling, overlapping, orthogonal, symmetric, real-valued, and compact-support properties. First, the blockwise implementation is developed so that the basis images can be locally controlled. The local control of basis images is shown to maintain orthogonality. This property leads a basis termination (BT) technique as a boundary operation. The technique overcomes the drawback of NS-LPPUFBs that the popular symmetric extension method is invalid. Through some experimental results of diagonal texture coding, the significance of the BT is verified.

    DOI: 10.1109/TIP.2011.2181527

    Web of Science

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  • A design method of multidimensional linear-phase paraunitary filter banks with a lattice structure Reviewed

    S Muramatsu, A Yamada, H Kiya

    IEEE TRANSACTIONS ON SIGNAL PROCESSING   47 ( 3 )   690 - 700   1999.3

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    A lattice structure of multidimensional (MD) linear-phase paraunitary filter banks (LPPUFB's) is proposed, which makes it possible to design such systems in a systematic manner. Our proposed structure can produce MD-LPPUFB's whose filters all have the region of support N(M Xi), where M and Xi are the decimation and positive integer diagonal matrices, respectively, and N(N) denotes the set of integer vectors in the fundamental parallelepiped of a matrix N, It is shown that if N(M) is reflection invariant with respect to some center, then the reflection invariance of N(M Xi) is guaranteed. This fact is important in constructing MD linear-phase filter banks because the reflection invariance is necessary for any linear-phase filter. Since our proposed system structurally restricts both the paraunitary and linear-phase properties, an unconstrained optimization process can be used to design MD-LPPUFB's. Our proposed structure is developed for both an even and an odd number of channels and includes the conventional 1-D system as a special case. It is also shown to be minimal, and the no-DC-leakage condition is presented. Some design examples will show the significance of our proposed structure for both the rectangular and nonrectangular decimation cases.

    DOI: 10.1109/78.747776

    Web of Science

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  • Extended overlap-add and -save methods for multirate signal processing Reviewed

    S Muramatsu, H Kiya

    IEEE TRANSACTIONS ON SIGNAL PROCESSING   45 ( 9 )   2376 - 2380   1997.9

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    The overlap-add method (OLA) and overlap-save method (OLS) are well known as efficient schemes for high-order FIR filtering, In this correspondence, new sampling rate conversion methods are proposed by extending the OLA and OLS and eliminating the redundancy caused by the conversion, First, for finite-duration sequences, a rate conversion with the DFT-domain approach is discussed, Then, using the result, the extended OLA and OLS are proposed for infinite-duration sequences. Last, the computational complexities of our proposed methods are shown.

    DOI: 10.1109/78.622960

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  • River Flow Path Control with Reinforcement Learning Reviewed

    Dongqi Liu, Yutaka Naito, Chen Zhang, Shogo Muramatsu, Hiroyasu Yasuda, Kiyoshi Hayasaka, Yu Otake

    Proc. of 2021 IEEE International Conference on Autonomous Systems (ICAS2021)   212 - 216   2021.8

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  • Image Restoration with Structured Deep Image Prior Reviewed

    Jikai Li, Ruiki Kobayashi, Shogo Muramatsu, Gwanggil Jeon

    Proc. of ITC-CSCC2021   2021.6

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  • Improvement of Object Detection from SAR Image Using Speckle Filter Reviewed

    M Ibnul Morshed, Shogo Muramatsu

    Proc. of ITC-CSCC2021   2021.6

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  • Sparse-Coded Dynamic Mode Decomposition on Graph for Prediction of River Water Level Distribution. Reviewed

    Yusuke Arai, Shogo Muramatsu, Hiroyasu Yasuda, Kiyoshi Hayasaka, Yu Otake

    Proc. of IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)   3225 - 3229   2021

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    DOI: 10.1109/ICASSP39728.2021.9414533

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    Other Link: https://dblp.uni-trier.de/db/conf/icassp/icassp2021.html#AraiMYHO21

  • Practical Dynamic Reliability Analysis with Spatiotemporal Features in Geotechnical Engineering Reviewed

    Yu Otake, Kyohei Shigeno, Yosuke Higo, Shogo Muramatsu

    Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards   2021

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  • Deep neural network for early image diagnosis of Stevens–Johnson syndrome/toxic epidermal necrolysis Reviewed

    Atsushi Fujimoto, Yuki Iwai, Shogo Muramatsu, Takashi Ishikawa, Satoru Shinkuma, Riichiro Abe

    The Journal of Allergy and Clinical Immunology: In Practice   2021

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  • Fixed-Point Arithmetic of l2-Norm Approximation for 2-Tuple Arrays with Rotated l1-Norm Evaluation Reviewed

    Yuya KODAMA, Shogo MURAMATSU, Hiroyoshi YAMADA

    Proceedings, APSIPA Annual Summit and Conference 2020   1216 - 1221   2020.12

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  • Image Restoration by Group Sparsity with Union of Hierarchical DirLOTs Reviewed

    Kazuki Sakashita, Shogo Muramatsu

    Proceedings, APSIPA Annual Summit and Conference 2020   1182 - 1187   2020.12

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  • Convolutional Nonlinear Dictionary with Cascaded Structure Filter Banks. Reviewed

    Ruiki Kobayashi, Shogo Muramatsu

    Proc. of IEEE/IEIE ICCE-Asia 2020   2020.11

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    Other Link: https://dblp.uni-trier.de/db/journals/corr/corr2009.html#abs-2009-00831

  • Characterisation of the static offset in the travelling wave in the cochlear basal turn Reviewed

    Takeru Ota, Fumiaki Nin, Samuel Choi, Shogo Muramatsu, Seishiro Sawamura, Genki Ogata, Mitsuo P. Sato, Katsumi Doi, Kentaro Doi, Tetsuro Tsuji, Satoyuki Kawano, Tobias Reichenbach, Hiroshi Hibino

    PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY   2020.4

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:SPRINGER HEIDELBERG  

    In mammals, audition is triggered by travelling waves that are evoked by acoustic stimuli in the cochlear partition, a structure containing sensory hair cells and a basilar membrane. When the cochlea is stimulated by a pure tone of low frequency, a static offset occurs in the vibration in the apical turn. In the high-frequency region at the cochlear base, multi-tone stimuli induce a quadratic distortion product in the vibrations that suggests the presence of an offset. However, vibrations below 100 Hz, including a static offset, have not been directly measured there. We therefore constructed an interferometer for detecting motion at low frequencies including 0 Hz. We applied the interferometer to record vibrations from the cochlear base of guinea pigs in response to pure tones. When the animals were exposed to sound at an intensity of 70 dB or higher, we recorded a static offset of the sinusoidally vibrating cochlear partition by more than 1 nm towards the scala vestibuli. The offset's magnitude grew monotonically as the stimuli intensified. When stimulus frequency was varied, the response peaked around the best frequency, the frequency that maximised the vibration amplitude at threshold sound pressure. These characteristics are consistent with those found in the low-frequency region and are therefore likely common across the cochlea. The offset diminished markedly when the somatic motility of mechanosensitive outer hair cells, the force-generating machinery that amplifies the sinusoidal vibrations, was pharmacologically blocked. Therefore, the partition offset appears to be linked to the electromotile contraction of outer hair cells.

    DOI: 10.1007/s00424-020-02373-6

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  • An offset component associated with the activity of outer hair cells in the cochlear travelling wave Reviewed

    Takeru Ota, Fumiaki Nin, Samuel Choi, Shogo Muramatsu, Seishiro Sawamura, Genki Ogata, Mitsuo P. Sato, Katsumi Doi, Kentaro Doi, Tetsuro Tsuji, Satoyuki Kawano, Tobias Reichenbach, Hiroshi Hibino

    Pflügers Archiv - European Journal of Physiology   2020

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  • DATA DRIVEN DYNAMIC RELIABILITY ANALYSIS BASED ON SPATIOTEMPORAL FEATURE EXTRACTION WITH MODE DECOMPOSITION: APPLICATION FOR EFFECTIVE STRESS DYNAMIC ANALYSIS Reviewed

    大竹雄, 茂野恭平, 渡邉慎也, 肥後陽介, 村松正吾

    土木学会論文集 C(地圏工学)(Web)   76 ( 2 )   142 - 157   2020

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    Language:Japanese   Publisher:Japan Society of Civil Engineers  

    <p> Recently, the need for the robust design and the resilience design methods under accidental loading of soil structures has been the subject of many discussions. Herein, we are developing a dynamic reliability analysis base on mode decomposition for evaluating the failure mode of the soil structure. This analysis features quantifying uncertainties related to the accuracy of the parameter settings. This paper describes the deformation calculation procedure for the case of a simple embankment on a liquefiable sand layer. We conducted a dynamic effective stress analysis to evaluate the liquefaction phenomenon in the sand layer. This study aimed to derive an alternative numerical analysis model that considers the space and time required for calculating the aforementioned deformed embankment.</p>

    DOI: 10.2208/jscejge.76.2_142

    CiNii Article

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  • BASIC STUDY ON OPTIMIZATION OF SENSOR PLACEMENTS FOR REAL TIME ALTERNATIVE SIMULATION

    庄司大河, 大竹雄, 茂野恭平, 肥後陽介, 村松正吾

    土木学会論文集 A2(応用力学)(Web)   76 ( 2 )   2020

  • VISUALIZATION OF MICRO MORPHOLOGY FOR SOIL MICROMECHANICS MODELING : AN APPLICATION OF SUPER-RESOLUTION TO X-RAY CT IMAGES

    遠藤尚希, 大竹雄, 肥後陽介, 村松正吾

    土木学会論文集 A2(応用力学)(Web)   76 ( 2 )   2020

  • Successive Stripe Artifact Removal Based on Robust PCA for Millimeter Wave Automotive Radar Imageive Radar Image Reviewed

    Weiwei Shan, Shogo Muramatsu, Hiroyoshi Yamada, Akira Oshima

    Proc. of 2019 Asia-Pacific Signal and Information Processing Association Annual Summit and Conference (APSIPA ASC)   2019.11

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  • OCT Volumetric Data Restoration with Latent Distribution of Refractive Index Reviewed

    Genki Fujii, Yuta Yoshida, Shogo Muramatsu, Shunsuke Ono, Samuel Choi, Takeru Ota, Fumiaki Nin, Hiroshi Hibino

    Proc. of 2019 IEEE International Conference on Image Processing (ICIP)   2019.9

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    Language:English   Publishing type:Research paper (international conference proceedings)  

    DOI: 10.1109/ICIP.2019.8803737

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  • In Vivo Tomographic Visualization of Intracochlear Vibration Using a Supercontinuum Multifrequency-Swept Optical Coherence Microscope Reviewed

    Samuel Choi, Fumiaki Nin, Takeru Ota, Kouhei Sato, Shogo Muramatsu, Hiroshi Hibino

    Biomedical Optics Express   10 ( 7 )   3317 - 3342   2019.7

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1364/BOE.10.003317

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  • Convolutional-Sparse-Coded Dynamic Mode Decomposition and Its Application to River State Estimation Reviewed

    Yuhei Kaneko, Shogo Muramatsu, Hiroyasu Yasuda, Kiyoshi Hayasaka, Yu Otake, Shunsuke Ono, Masahiro Yukawa

    Proc. of 2019 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)   1872 - 1876   2019.5

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    Language:English   Publishing type:Research paper (international conference proceedings)  

    This work proposes convolutional-sparse-coded dynamic mode decomposition<br />
    (CSC-DMD) by unifying extended dynamic mode decomposition (EDMD) and<br />
    convolutional sparse coding. EDMD is a data driven analysis method for<br />
    describing a nonlinear dynamical system with a linear time-evolution equation.<br />
    Compared with existing EDMD methods, CSC-DMD has an advantage of reflecting<br />
    spatial structure of the target. As an example, the proposed method is applied<br />
    to river bed shape estimation from the water surface observation. The<br />
    estimation problem is reduced to sparsity-aware restoration with a hard<br />
    constraint, which is given by the CSC-DMD prediction, where the algorithm is<br />
    derived by the primal-dual splitting method. A time series set of water surface<br />
    and bed shape measured through an experimental river setup is used to train and<br />
    test the system. From the result, the significance of the proposed method is<br />
    verified.

    DOI: 10.1109/ICASSP.2019.8683848

    arXiv

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  • Graph Learning & Fast Transform Coding of 3D River Data Reviewed

    Weihang Liao, Gene Cheung, Shogo Muramatsu, Hiroyasu Yasuda, Kiyoshi Hayasaka

    Proc. of 2018 Asia-Pacific Signal and Information Processing Association Annual Summit and Conference (APSIPA ASC)   1313 - 1317   2018.11

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  • Single-image Super-resolution using Complex Nonseparable Oversampled Lapped Transforms Reviewed

    Satoshi Nagayama, Shogo Muramatsu, Hiroyoshi Yamada

    Proc. of 2018 Asia-Pacific Signal and Information Processing Association Annual Summit and Conference (APSIPA ASC)   1309 - 1312   2018.11

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  • Study on Imaging Method and Doppler Effect for Millimeter Wave Automotive SAR Reviewed

    Takumi Kobayashi, Hiroyoshi Yamada, Yuuichi Sugiyama, Shogo Muramatsu, Yoshio Yamagchi

    Proc. of 2018 International Symposium on Antennas and Propagation (ISAP)   2018.10

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  • Fundamental Study on Ambiguity Suppression of Automotive Squint-mode MW-SAR by Using SIMO Radar Reviewed

    Akira Oshima, Hiroyoshi Yamada, Yoshio Yamaguchi, Shogo Muramatsu

    Proc. of 2018 IEEE International Workshop on Electromagnetics:Applications and Student Innovation Competition (iWEM)   2018.8

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    DOI: 10.1109/iWEM.2018.8536598

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  • OCT Volumetric Data Restoration via Primal-Dual Plug-and-Play Method Reviewed

    Shogo Muramatsu, Samuel Choi, Shunske Ono, Takeru Ota, Fumiaki Nin, Hiroshi Hibino

    Proc. of 2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)   801 - 805   2018.4

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    DOI: 10.1109/ICASSP.2018.8462343

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  • Complex nonseparable oversampled lapped transform for sparse representation of millimeter wave radar image Reviewed

    Satoshi Nagayama, Shogo Muramatsu, Hiroyoshi Yamada, Yuuichi S. Giyama

    Proceedings - International Conference on Image Processing, ICIP   2017-   2716 - 2720   2018.2

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    This work generalizes an existing framework of nonseparable oversampled lapped transforms (NSOLTs) to effectively represent complex-valued images. The original NSOLTs are lattice-structure-based redundant transforms, which satisfy the linear-phase, compact-supported and real-valued property. The lattice structure is able to constitute a Parseval tight frame with rational redundancy and to generate a dictionary with directional atomic images. In this study, a generalized structure of NSOLTs is proposed to cover complex-valued atomic images. The novel transform is referred to as a complex NSOLT (CNSOLT). The effectiveness of the structure is verified by evaluating the sparse approximation performance using the iterative hard thresholding (IHT) algorithm for a millimeter wave radar image.

    DOI: 10.1109/ICIP.2017.8296776

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  • Millimeter wave radar image denoising with complex nonseparable oversampled lapped transform. Reviewed

    Satoshi Nagayama, Shogo Muramatsu, Hiroyoshi Yamada, Yuuichi Sugiyama

    Proc. of 2017 Asia-Pacific Signal and Information Processing Association Annual Summit and Conference (APSIPA ASC)   1824 - 1829   2017.12

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    DOI: 10.1109/APSIPA.2017.8282330

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  • Adaptive Learning Rate Control for Nonseparable Oversampled Lapped Transform Design Reviewed

    Genki Fujii, Shogo Muramatsu

    Proc. of 2017 International Technical Conference on Circuits, Systems, Computers, and Communications(ITC-CSCC)   186 - 189   2017.7

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  • Multifrequency-swept optical coherence microscopy for highspeed full-field tomographic vibrometry in biological tissues Reviewed

    Samuel Choi, Keita Sato, Takeru Ota, Fumiaki Nin, Shogo Muramatsu, Hiroshi Hibino

    BIOMEDICAL OPTICS EXPRESS   8 ( 2 )   608 - 621   2017.2

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    Because conventional laser Doppler vibrometry or Doppler optical coherence tomography require mechanical scanning probes that cannot simultaneously measure the wide-range dynamics of bio-tissues, a multifrequency-swept optical coherence microscopy with wide-field heterodyne detection technique was developed. A 1024 x 1024 x 2000 voxel volume was acquired with an axial resolution of similar to 1.8 mu m and an acquisition speed of 2 s. Vibration measurements at 10 kHz were performed over a wide field of view. Wide-field tomographic vibration measurements of a mouse tympanic membrane are demonstrated to illustrate the applicability of this method to live animals.(C) 2017 Optical Society of America

    DOI: 10.1364/BOE.8.000608

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  • Embedded Implementation Model of 2-D Non-separable Oversampled Lapped Transforms for Video Processing Reviewed

    Keita Imai, Shogo Muramatsu

    Proc. of 2016 International Technical Conference on Circuits, Systems, Computers, and Communications(ITC-CSCC)   375 - 378   2016.7

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  • Boundary operation of 2D non-separable oversampled lapped transforms Reviewed

    Kosuke Furuya, Shintaro Hara, Kenta Seino, Shogo Muramatsu

    APSIPA Transactions on Signal and Information Processing   5   2016.4

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    DOI: 10.1017/ATSIP.2016.3

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  • Fast Convolution Technique for Non-separable Oversampled Lapped Transforms Reviewed

    Kota Horiuchi, Shogo Muramatsu

    2016 ASIA-PACIFIC SIGNAL AND INFORMATION PROCESSING ASSOCIATION ANNUAL SUMMIT AND CONFERENCE (APSIPA)   1 - 6   2016

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    In this study, an acceleration technique for nonseparable oversampled lapped transforms (NSOLT) is proposed. NSOLT is a non-separable transform which simultaneously satisfies the oversampled, overlapped, symmetric, tight-frame, real-valued and compact-supported property. From the non-separability, NSOLT is valid for sparsely representing edges and textures with oblique directions as a linear generative model. In this paper, a fast convolution technique for NSOLT is proposed by using fast Fourier transform (FFT) and frequency-domain multirate processing. The analysis and synthesis processing for 2-D and 3-D data is evaluated through GPGPU implementation, and the processing speed of the proposed structure is compared with the conventional lattice-based one to show the effectiveness.

    DOI: 10.1109/APSIPA.2016.7820816

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  • FAST IMAGE SUPER-RESOLUTION VIA MULTIPLE DIRECTIONAL TRANSFORMS Reviewed

    Zhiyu Chen, Shogo Muramatsu, Yoshito Abe

    2016 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING (ICIP)   1434 - 1438   2016

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    Recently, single image super-resolution (SISR) is very important research field to reconstruct a high-resolution (HR) image from a low resolution (LR) image. However, existing image super-resolution approaches require a lot of computations or consider parameters for various situations. This paper proposes an efficient and simple image super-resolution technique using multiple directional lapped orthogonal transforms (M-DirLOTs). It captures high-frequency informations, e.g. edges and slant textures, of images efficiently, and reduce the computational cost. Simultaneously, this model avoids any a priori hypotheses on the LR picture. The proposed method overcomes some disadvantages of existing methods. Experimental results show that the proposed method is able to significantly improve the super resolution performance.

    DOI: 10.1109/ICIP.2016.7532595

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  • EFFICIENT PARAMETER OPTIMIZATION FOR EXAMPLE-BASED DESIGN OF NONSEPARABLE OVERSAMPLED LAPPED TRANSFORM Reviewed

    Shogo Muramatsu, Masaki Ishii, Zhiyu Chen

    2016 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING (ICIP)   3618 - 3622   2016

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    This paper proposes an efficient design method of nonseparable oversampled lapped transform (NSOLT). NSOLT is a multidimensional redundant transform which satisfies the nonseparable, symmetric, real-valued, overlapped, compact-supported and perfect reconstruction property. A typical example-based design approach, which consists of sparse coding and parameter optimization, is applicable to NSOLT. In the previous implementation, however, the parameter optimization stage dominated the computation. The main reason is that the quasi-Newton method with numerical gradient of the objective function was adopted. To reduce the computational cost, the analytical gradient is derived and introduced. For further acceleration, the quasi-Newton method is replaced by stochastic gradient descent. Through some experiments, the significance of the proposed method is verified.

    DOI: 10.1109/ICIP.2016.7533034

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  • MULTI-FOCUS PIXEL-BASED IMAGE FUSION IN DUAL DOMAIN Reviewed

    Zhiyu Chen, Shogo Muramatsu

    2016 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH AND SIGNAL PROCESSING PROCEEDINGS   1736 - 1740   2016

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    Redundant-transform-based image fusion approaches require a lot of memory and computations. This paper proposes an effective and efficient multi-focus image fusion technique in dual domain using a redundant transform. The proposed scheme captures high-frequency informations, e.g. edges and slant textures, of images efficiently, and reduce the computational cost. The proposed scheme extracts the high-frequency information of images with multiple directional lapped orthogonal transforms (M-DirLOTs) through the following procedure: (1) reconstruct the detail image using high-pass sub-bands, (2) execute a fusion operation in spatial domain through joint measurement and (3) improve the performance by mathematical morphology processing. The proposed method overcomes some disadvantages of traditional transform-based and spatial-based fusion techniques. Experimental results show that the proposed method is able to significantly improve the fusion performance.

    DOI: 10.1109/ICASSP.2016.7471974

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  • Multi-Focus Image Fusion Based on Multiple Directional LOTs Reviewed

    Zhiyu Chen, Shogo Muramatsu

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E98A ( 11 )   2360 - U157   2015.11

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    This letter proposes an image fusion method which adopts a union of multiple directional lapped orthogonal transforms (DirLOTs). DirLOTs are used to generate symmetric orthogonal discrete wavelet transforms and then to construct a union of unitary transforms as a redundant dictionary with a multiple directional property. The multiple DirLOTs can overcome a disadvantage of separable wavelets to represent images which contain slant textures and edges. We analyse the characteristic of local luminance contrast, and propose a fusion rule based on interscale relation of wavelet coefficients. Relying on the above, a novel image fusion method is proposed. Some experimental results show that the proposed method is able to significantly improve the fusion performance from those with the conventional discrete wavelet transforms.

    DOI: 10.1587/transfun.E98.A.2360

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  • SURE-LET poisson denoising with multiple directional LOTs Reviewed

    Zhiyu Chen, Shogo Muramatsu

    IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences   E98A ( 8 )   1820 - 1828   2015.8

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    This paper proposes a Poisson denoising method with a union of directional lapped orthogonal transforms (DirLOTs). DirLOTs are 2-D non-separable lapped orthogonal transforms with directional characteristics under the fixed-critically-subsampling, overlapping, orthonormal, symmetric, real-valued and compact-support property. In this work, Dir- LOTs are used to generate symmetric orthogonal discrete wavelet transforms and then a redundant dictionary as a union of unitary transforms. The multiple directional property is suitable for representing natural images which contain diagonal textures and edges. Multiple DirLOTs can overcome a disadvantage of separable wavelets in representing diagonal components. In addition to this feature, multiple DirLOTs make transformbased denoising performance better through the redundant representation. Experimental results show that the combination of the variance stabilizing transformation (VST), Steinïs unbiased risk estimator-linear expansion of threshold (SURE-LET) approach and multiple DirLOTs is able to significantly improve the denoising performance.

    DOI: 10.1587/transfun.E98.A.1820

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  • 3-D OCT Data Denoising with Nonseparable Oversampled Lapped Transform Reviewed

    Shogo Muramatsu, Samuel Choi, Takumi Kawamura

    2015 ASIA-PACIFIC SIGNAL AND INFORMATION PROCESSING ASSOCIATION ANNUAL SUMMIT AND CONFERENCE (APSIPA)   901 - 906   2015

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    This paper proposes 3-D OCT data denoising with nonseparable oversampled lapped transform (NSOLT), and examines the effectiveness through experiments. NSOLT is a lattice-based redundant transform which simultaneously satisfies the symmetric, real-valued and compact-support property. It is possible to apply a dictionary learning technique to the design by preparing examples. NSOLT is capable of having rational redundancy by controlling the number of channels and decimation ratio. In this study, a denoising technique is proposed by combining learned NSOLT dictionary and iterative hard thresholding (IHT), and the performance of the proposed method is evaluated for 3-D OCT data. It is verified through robust median estimator of noise variance and structural similarity index measure (SSIM) that the proposed technique yields effective denoising performance with moderate redundancy.

    DOI: 10.1109/APSIPA.2015.7415402

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  • STRUCTURED DICTIONARY LEARNING WITH 2-D NON-SEPARABLE OVERSAMPLED LAPPED TRANSFORM Reviewed

    Shogo Muramatsu

    2014 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH AND SIGNAL PROCESSING (ICASSP)   2624 - 2628   2014

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    This work proposes a novel design method of a two-dimensional (2-D) Non-Separable Oversampled Lapped Transform (NSOLT) for a given image by introducing a typical two stage procedure of dictionary learning. NSOLT is a lattice-structure-based transform and yields a redundant dictionary of which atoms satisfy the nonseparable, symmetric, real-valued, overlapping and compact-support property. In addition, the Parseval tight frame constraint can structurally be imposed, while the redundancy R is flexibly controlled by the ratio of the number of channels P and the downsampling ratio M. Compared with the other dictionary learning approaches, the proposed method is moderately structured so that it is capable of multiscale construction as well as atom termination at image boundary. The significance of the proposed method is verified by showing an example of learned dictionary and sparse approximation results.

    DOI: 10.1109/ICASSP.2014.6854075

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  • POISSON DENOISING WITH MULTIPLE DIRECTIONAL LOTS Reviewed

    Zhiyu Chen, Shogo Muramatsu

    2014 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH AND SIGNAL PROCESSING (ICASSP)   1225 - 1229   2014

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    This paper proposes a Poisson denoising with a union of directional lapped orthogonal transforms (DirLOTs). DirLOTs are 2-D non-separable lapped orthogonal transforms with directional characteristics. Its bases overcome a disadvantage of the separable wavelet image denoising for the diagonal textures and edges. Based on this feature, multiple DirLOTs are used to improve the performance by introducing redundant representation with multiple directions. Experimental results show the combination of the variance stabilizing transformation (VST), Stein's unbiased risk estimator-linear expansion of thresholds (SURE-LET) approach and multiple DirLOTs is able to significantly improve the denoising performance, and verify the feasibility of the proposed method.

    DOI: 10.1109/ICASSP.2014.6853792

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  • POISSON DENOISING WITH MULTIPLE DIRECTIONAL LOTS Reviewed

    Zhiyu Chen, Shogo Muramatsu

    2014 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH AND SIGNAL PROCESSING (ICASSP)   98-A ( 8 )   1820 - 1828   2014

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    This paper proposes a Poisson denoising with a union of directional lapped orthogonal transforms (DirLOTs). DirLOTs are 2-D non-separable lapped orthogonal transforms with directional characteristics. Its bases overcome a disadvantage of the separable wavelet image denoising for the diagonal textures and edges. Based on this feature, multiple DirLOTs are used to improve the performance by introducing redundant representation with multiple directions. Experimental results show the combination of the variance stabilizing transformation (VST), Stein's unbiased risk estimator-linear expansion of thresholds (SURE-LET) approach and multiple DirLOTs is able to significantly improve the denoising performance, and verify the feasibility of the proposed method.

    DOI: 10.1587/transfun.E98.A.1820

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  • Transposition-based Architecture of 2-D Non-separable Oversampled Lapped Transforms Reviewed

    Kenta Seino, Kosuke Furuya, Shogo Muramatsu

    2014 ASIA-PACIFIC SIGNAL AND INFORMATION PROCESSING ASSOCIATION ANNUAL SUMMIT AND CONFERENCE (APSIPA)   1 - 6   2014

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    This paper proposes an embedded implementation architecture of 2-D Non-separable Oversampled Lapped Transform (NSOLT). NSOLT yields a frame for image representation which satisfies the symmetry and overlapping property. Since the redundancy can be set to an arbitrary rational value, high performance image processing can be realized while saving memory consumption. This work mainly concerns the implementation issue. In general, non-separable systems require more computational resources than separable ones. However, NSOLT can be implemented by a separable manner thanks to the order factorable property. Based on the fact, a transposition-based architecture is proposed, and the significance is verified through the estimation of required hardware resources and its processing speed. The hardware module performances are evaluated for Xilinx XC7Z020-1CLG484 (Zynq).

    DOI: 10.1109/APSIPA.2014.7041733

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  • Image Restoration with Multiple DirLOTs Reviewed

    Natsuki Aizawa, Shogo Muramatsu, Masahiro Yukawa

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E96A ( 10 )   1954 - 1961   2013.10

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    A directional lapped orthogonal transform (DirLOT) is an orthonormal transform of which basis is allowed to be anisotropic with the symmetric, real-valued and compact-support property. Due to its directional property, DirLOT is superior to the existing separable transforms such as DCT and DWT in expressing diagonal edges and textures. The goal of this paper is to enhance the ability of DirLOT further. To achieve this goal, we propose a novel image restoration technique using multiple DirLOTs. This paper generalizes an image denoising technique in [1], and expands the application of multiple DirLOTs by introducing linear degradation operator P. The idea is to use multiple DirLOTs to construct a redundant dictionary. More precisely, the redundant dictionary is constructed as a union of symmetric orthonormal discrete wavelet transforms generated by DirLOTs. To select atoms fitting a target image from the dictionary, we formulate an image restoration problem as an l(1)-regularized least square problem, which can efficiently be solved by the iterative-shrinkage/thresholding algorithm (ISTA). The proposed technique is beneficial in expressing multiple directions of edges/textures. Simulation results show that the proposed technique significantly outperforms the non-subsampled Haar wavelet transform for deblurring, super-resolution, and inpainting.

    DOI: 10.1587/transfun.E96.A.1954

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  • Embedded Implementation of 2-D Nonseparable Linear-Phase Paraunitary Filter Banks for Video Processing Reviewed

    Kosuke Furuya, Shintaro Hara, Shogo Muramatsu

    Proc. of 2013 International Workshop on Advanced Image Technology (IWAIT)   605 - 609   2013.1

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  • FISTA-Based Image Restoration with Multiple DirLOTs Reviewed

    Natsuki Aizawa, Shogo Muramatsu

    Proc. of 2013 International Workshop on Advanced Image Technology (IWAIT)   642 - 647   2013.1

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  • Lens Distortion Estimation and Compensation for Sheet-Metal Inspection System Reviewed

    Norihisa Terasawa, Shinya Kitazawa, Hidenori Watanabe, Shogo Muramatsu, Takamasa Suzuki, Mitsuyoshi Murata, Toshiro Oitate

    Proc. of 2013 International Workshop on Advanced Image Technology (IWAIT)   648 - 653   2013.1

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  • COLOR-TONE SIMILARITY OF DIGITAL IMAGES Reviewed

    Hisakazu Kikuchi, S. Kataoka, S. Muramatsu, Heikki Huttunen

    2013 20TH IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING (ICIP 2013)   393 - 397   2013

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    A color-tone similarity index (CSIM) between two color images is presented. CSIM is defined by a statistical analysis of cumulative histograms in a hue-oriented color space. It characterizes the color distributions, while the existing structural similarity index reflects the spatial structure involved with grayscale images. The behaviors of CSIM are checked by the comparisons of color code chips. Through an image quality assessment on TID2008, the correlation between CSIM and the mean opinion score was proved to be statistically significant.

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  • Boundary Operation of 2-D Non-separable Oversampled Lapped Transforms Reviewed

    Kosuke Furuya, Shintaro Hara, Shogo Muramatsu

    2013 ASIA-PACIFIC SIGNAL AND INFORMATION PROCESSING ASSOCIATION ANNUAL SUMMIT AND CONFERENCE (APSIPA)   1 - 8   2013

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    This paper proposes a boundary operation technique of 2-D non-separable oversampled lapped transforms (NSOLT). The proposed technique is based on a lattice structure consisting of the 2-D separable block discrete cosine transform (DCT) and non-separable redundant support-extension processes. The atoms are allowed to be anisotropic with the oversampled, overlapping, symmetric, real-valued, and compact-support property. First, the blockwise implementation is developed so that the atoms can be locally controlled. The local control of atoms is shown to maintain perfect reconstruction. This property leads an atom termination (AT) technique as a boundary operation. The technique overcomes the drawback of NSOLT that the popular symmetric extension method is invalid. Through some experimental results, the significance of AT is verified.

    DOI: 10.1109/APSIPA.2013.6694258

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  • Look-up-table-based exponential computation and application to an EM algorithm for GMM Reviewed

    Hidenori Watanabe, Shogo Muramatsu

    IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences   E96-A ( 5 )   935 - 939   2013

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    This work proposes an exponential computation with lowcomputational complexity and applies this technique to the expectation-maximization (EM) algorithm for Gaussian mixture model (GMM). For certain machine-learning techniques, such as the EM algorithm for the GMM, fast and low-cost implementations are preferred over high precision ones. Since the exponential function is frequently used in machinelearning algorithms, this work proposes reducing computational complexity by transforming the function into powers of two and introducing a lookup table. Moreover, to improve efficiency the look-up table is scaled. To verify the validity of the proposed technique, this work obtains simulation results for the EM algorithm used for parameter estimation and evaluates the performances of the results in terms of the mean absolute error and computational time. This work compares our proposed method against the Taylor expansion and the exp() function in a standard C library, and shows that the computational time of the EM algorithm is reduced while maintaining comparable precision in the estimation results. Copyright © 2013 The Institute of Electronics.

    DOI: 10.1587/transfun.E96.A.935

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  • LATTICE STRUCTURES FOR 2-D NON-SEPARABLE OVERSAMPLED LAPPED TRANSFORMS Reviewed

    Shogo Muramatsu, Natsuki Aizawa

    2013 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH AND SIGNAL PROCESSING (ICASSP)   5632 - 5636   2013

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    This paper proposes lattice structures for two-dimensional (2-D) non-separable (NS) oversampled (OS) lapped transforms. The proposed systems consist of the 2-D separable discrete cosine transform and NS support extension processes, and allow us to simply realize rational redundancy as well as the overlapping, paraunitary (PU), symmetric, real-valued and compact support property. The lattice structures have two aspects. One is an extention of OS linear-phase (LP) perfect reconstruction (PR) filter banks (FBs) to the 2-D NS case. The other is a generalization of 2-D NS LPPR FBs to the OS case. The significance is verified by showing some design examples and image restoration results with the iterative shrink-age/thresholding algorithm (ISTA).

    DOI: 10.1109/ICASSP.2013.6638742

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  • IMAGE RESTORATION WITH 2-D NON-SEPARABLE OVERSAMPLED LAPPED TRANSFORMS Reviewed

    Shogo Muramatsu, Natsuki Aizawa

    2013 20TH IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING (ICIP 2013)   1051 - 1055   2013

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    This work proposes to apply a two-dimensional (2-D) non-separable oversampled lapped transform (NSOLT) to image restoration. NSOLT is a lattice-structure-based redundant transform which satisfies the symmetric, real-valued and compact-support property. The lattice structure is able to constitute a Parseval frame with rational redundancy and produce a dictionary with directional atoms. In this study, the performance for deblurring, super-resolution and inpainting is evaluated. The iterative-shrinkage/thresholding algorithm (ISTA) is adopted to show the significance of NSOLT in the image restoration applications. It is verified that the six-level NSOLT with redundancy less than two yields superior or comparable restoration performance to the two-level non-subsampled Haar transform of redundancy seven in both of PSNR and SSIM.

    DOI: 10.1109/ICIP.2013.6738217

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  • Simple Bitplane Coding and Its Application to Multi-Functional Image Compression Reviewed

    Hisakazu Kikuchi, Ryosuke Abe, Shogo Muramatsu

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E95A ( 5 )   938 - 951   2012.5

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    A simple image compression scheme is presented for various types of images, which include color/grayscale images, color-quantized images, and bilevel Images such as document and digital halftone images. It is a bitplane coding composed of a new context modeling and adaptive binary arithmetic coding. A target bit to be encoded is conditioned by the estimates of the neighboring pixels including non-causal locations. Several functionalities are also integrated. They are arbitrary shaped ROI transmission, selective tile partitioning, accuracy scalability, and others. The proposed bitplane codec is competitive with JPEG-LS in lossless compression of 8-bit grayscale and 24-bit color images. The proposed codec is close to JBIG2 in bilevel image compression. It outperforms the existing standards in compression of 8-bit color-quantized images.

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  • Reversible Implementations of Irreversible Component Transforms and Their Comparisons in Image Compression Reviewed

    Junghyeun Hwang, Hisakazu Kikuchi, Shogo Muramatsu, Kazuma Shinoda, Jaeho Shin

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E95A ( 4 )   824 - 828   2012.4

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    Reversible color component transforms derived by the LU factorization are briefly described. It is possible to obtain an reversible implementation to a given component transform, even if the original transform is irreversible. Some examples are presented and their performances are compared in image compression.

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  • A Structure-Enhanced Tone Mapping Algorithm for High Dynamic Range Scenes Reviewed

    Junghyeun Hwang, Hisakazu Kikuchi, Shogo Muramatsu, Jaeho Shin

    Proc. of 2012 International Conference on Electronics, Information and Communications   2012.2

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  • Image Restoration with Union of Directional Orthonormal DWTs Reviewed

    Shogo Muramatsu, Natsuki Aizawa, Masahiro Yukawa

    2012 ASIA-PACIFIC SIGNAL AND INFORMATION PROCESSING ASSOCIATION ANNUAL SUMMIT AND CONFERENCE (APSIPA ASC)   1 - 4   2012

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    This work proposes to apply directional lapped orthogonal transforms to image restoration. A DirLOT is an orthonormal transform of which basis is allowed to be anisotropic with the symmetric, real-valued and compact-support property. In this work, DirLOTs are used to generate symmetric orthonormal discrete wavelet transforms and then a redundant dictionary as a union of unitary transforms. The multiple directional property is suitable for representing natural images which contain diagonal edges and textures. The performances of deblurring, super-resolution and inpainting are evaluated for several images with the iterative-shrinkage/thresholding algorithm. It is verified that the proposed dictionary yields comparable or superior restoration performance to the non-subsampled Haar transform.

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  • Color-Tone Similarity on Digital Images Reviewed

    Hisakazu Kikuchi, Heikki Huttunen, Junghyeun Hwang, Masahiro Yukawa, Shogo Muramatsu, Jaeho Shin

    2012 ASIA-PACIFIC SIGNAL AND INFORMATION PROCESSING ASSOCIATION ANNUAL SUMMIT AND CONFERENCE (APSIPA ASC)   393 - 397   2012

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    A color-tone similarity index (CSIM) between two color images is presented and another index, picture similarity index (PSIM), is also given for a comprehensive similarity comparison between color images. CSIM is defined by a statistical analysis of cumulative histograms in a hue-oriented color space. It characterizes the color distributions, while the existing structural similarity index reflects the spatial structure involved with grayscale images. The behaviors of CSIM are checked by the comparisons of color code chips. Experimental results are given. The proposed indexes combined with SSIM are hopeful to provide a tool for color image quality analysis (IQA).

    DOI: 10.1109/ICIP.2013.6738081

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  • IMAGE DENOISING WITH UNION OF DIRECTIONAL ORTHONORMAL DWTS Reviewed

    Shogo Muramatsu, Dandan Han

    2012 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH AND SIGNAL PROCESSING (ICASSP)   1089 - 1092   2012

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    A novel image denoising technique is proposed by using directional lapped orthogonal transforms (DirLOTs). DirLOTs satisfy orthogonality and the bases are allowed to be anisotropic with the fixed-critically-subsampling, overlapping, symmetric, real-valued and compact-support property. In this work, DirLOTs are used to construct directional symmetric orthonormal discrete wavelet transforms and then the bases are adopted to generate a redundant dictionary with several directions. The multiple directional property is suitable for representing natural images which contain diagonal edges and textures. The proposed dictionary is applied to solve the basis pursuit denoising problem. The denoising performance is evaluated for several images through the heuristic shrinkage and block-coordinate-relaxation algorithm. It is verified that the proposed technique is simple but yields perceptually preferable results.

    DOI: 10.1109/ICASSP.2012.6288076

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  • SURE-LET Image Denoising with Multiple Directional LOTs Reviewed

    Shogo Muramatsu

    2012 PICTURE CODING SYMPOSIUM (PCS)   229 - 232   2012

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    This paper proposes to adopt a union of directional lapped orthogonal transforms (DirLOTs) to the SURE-LET image denoising. DirLOTs are 2-D non-separable transforms and can have directional characteristics under the fixed-critically-subsampling, overlapping, orthogonal, symmetric, real-valued and compact-support property. As a previous work, the author showed that a DirLOT overcomes a disadvantage of separable wavelet image denoising for diagonal textures and edges. Since there remains a problem that the approach is applicable only to a single geometric direction, this work further investigates to improve the performance by introducing redundant representation with multiple directions. Through some experimental results, it is verified that the proposed technique shows better performance than the traditional single wavelet approach for natural images with rich amount of geometrical structures.

    DOI: 10.1109/PCS.2012.6213334

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  • Image detection of inner wall surface of holes in metal sheets through polarization using a 3D TV monitor Reviewed

    Takamasa Suzuki, Katsunori Nakano, Shogo Muramatsu, Toshiro Oitate

    OPTICAL METROLOGY AND INSPECTION FOR INDUSTRIAL APPLICATIONS II   8563   2012

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    We propose an effective technique for optically detecting images of the inner hole-surface of a hole (hereafter, referred to as the hole-surface) using the polarization property of a 3D television (TV) monitor. The polarized light emitted by the TV monitor illuminates the hole-surfaces present in the test target placed on the screen of the monitor. When the polarizer placed in front of a camera lens is adjusted such that the camera captures a dark image for the transmitted light, only the highlighted hole-surfaces are visible in the captured image.

    DOI: 10.1117/12.999726

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  • Color-Tone Similarity on Digital Images Reviewed

    Hisakazu Kikuchi, Heikki Huttunen, Junghyeun Hwang, Masahiro Yukawa, Shogo Muramatsu, Jaeho Shin

    2012 ASIA-PACIFIC SIGNAL AND INFORMATION PROCESSING ASSOCIATION ANNUAL SUMMIT AND CONFERENCE (APSIPA ASC)   1 - 4   2012

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    A color-tone similarity index (CSIM) between two color images is presented and another index, picture similarity index (PSIM), is also given for a comprehensive similarity comparison between color images. CSIM is defined by a statistical analysis of cumulative histograms in a hue-oriented color space. It characterizes the color distributions, while the existing structural similarity index reflects the spatial structure involved with grayscale images. The behaviors of CSIM are checked by the comparisons of color code chips. Experimental results are given. The proposed indexes combined with SSIM are hopeful to provide a tool for color image quality analysis (IQA).

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    Other Link: http://dblp.uni-trier.de/db/conf/apsipa/apsipa2012.html#conf/apsipa/KikuchiHHYMS12

  • Computerized Sheet-Metal Inspection Based on the Cross Network Communication Reviewed

    Takamasa Suzuki, Kotaro Sato, Shogo Muramatsu, Mitsuyoshi Murata, Toshiro Oitate

    MECHANICAL ENGINEERING AND MATERIALS, PTS 1-3   152-154   331 - +   2012

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    A non-traditional processing cycle for sheet-metal working based on the computerized image processing techniques is proposed. This novel system enables the effective fabrication cycle that realizes automatic inspection, quick delivery, and cost reduction.

    DOI: 10.4028/www.scientific.net/AMM.152-154.331

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  • SURE-LET Image Denoising with Directional LOTs Reviewed

    Shogo Muramatsu, Dandan Han, Hisakazu Kikuchi

    Proc. of 2011 Asia Pacific Signal and Information Proc. Assoc. Annual Summit and Conf. (APSIPA ASC)   2011.10

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  • An Investigation on the Quality of Denoised Images Reviewed

    Peter Ndajah, Hisakazu Kikuchi, Masahiro Yukawa, Hidenori Watanabe, Shogo Muramatsu

    International Journal of Circuits, Systems, and Signal Processing   5 ( 4 )   423 - 434   2011.7

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  • Statistical Edge Detector with GMM Classifier Reviewed

    Hidenori Watanabe, Yuji Kikuchi, Shogo Muramatsu, Toshiro Oitate, Mitsuyoshi Murata, Takamasa Suzuki

    Proc. of 2011 26th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   611 - 614   2011.6

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  • A reproduction model of film grain texture for digital movies Reviewed

    Muyesaier Mulaaihemaiti, Shun Munekata, Junghyeun Hwang, Hisakazu Kikuchi, Shogo Muramatsu, Masahiro Yukawa, Heikki Huttunen, Jaeho Shin

    Proc. of 2011 26th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   819 - 822   2011.6

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  • Edge-aware tone mapping algorithm for high dynamic range imagery Reviewed

    Junghyeun Hwang, Hisakazu Kikuchi, Shogo Muramatsu, Jaeho Shin

    Proc. of 2011 26th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   804 - 807   2011.6

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  • Fast Algorithm and Efficient Implementation of GMM-Based Pattern Classifiers Reviewed

    Hidenori Watanabe, Shogo Muramatsu

    JOURNAL OF SIGNAL PROCESSING SYSTEMS FOR SIGNAL IMAGE AND VIDEO TECHNOLOGY   63 ( 1 )   107 - 116   2011.4

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    This paper proposes a fast decision algorithm in pattern classification based on Gaussian mixture models (GMM). Statistical pattern classification problems often meet a situation that comparison between probabilities is obvious and involve redundant computations. When GMM is adopted for the probability model, the exponential function should be evaluated. This work firstly reduces the exponential computations to simple and rough interval calculations. The exponential function is realized by scaling and multiplication with powers of two so that the decision is efficiently realized. For finer decision, a refinement process is also proposed. In order to verify the significance, experimental results on TI DM6437 EVM board and TED TB-3S-3400DSP-IMG board are shown through the application to a color extraction problem. It is verified that the classification was almost completed without any refinement process and the refinement process can proceed the residual decisions.

    DOI: 10.1007/s11265-009-0439-z

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  • Online optical verification system for sheet-metal processing Reviewed

    Takamasa Suzuki, Kotaro Sato, Shogo Muramatsu, Mitsuyoshi Murata, Toshiro Oitate

    2011 INTERNATIONAL CONFERENCE ON OPTICAL INSTRUMENTS AND TECHNOLOGY: OPTOELECTRONIC MEASUREMENT TECHNOLOGY AND SYSTEMS   8201   2011

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    We propose and demonstrate a novel processing cycle for sheet-metal working based on the computerized image processing techniques. The interconnected test system based on the cross network communication enables the effective fabrication cycle that realizes automatic inspection, quick delivery, and cost reduction.

    DOI: 10.1117/12.906564

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  • A Total Variation-Morphological Image Edge Detection Approach Reviewed

    Peter Ndajah, Hisakazu Kikuchi, Shogo Muramatsu, Masahiro Yukawa, Francis Benyah

    RECENT RESEARCHES IN TELECOMMUNICATIONS, INFORMATICS, ELECTRONICS & SIGNAL PROCESSING   148 - +   2011

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    We present image edge detection using the total variation functional and morphological methods. First, we derive the total variation functional from first principles and vector gradient method. The total variation functional is then minimized using the Euler-Lagrange optimization method. The steady state equation which results from the minimization of the total variation functional is then used as an anisotrpic filter on images. While the total variation method has proven to be a better edge detector than the Marr-Hildreth method, it also segments the image into regions delineated by strong edges. To achieve results similar to the Marr-Hildreth method, we apply morphological considerations. We develop new operations based on erosion, dilation, opening and closing to achieve morphological edge detection of total variation filtered images.

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  • Design Method of Directional GenLOT with Trend Vanishing Moments Reviewed

    Shogo Muramatsu, Tomoya Kobayashi, Dandan Han, Hisakazu Kikuchi

    Proc. of 2010 Asia-Pacific Signal and Information Processing Association Annual Summit and Conference (APSIPA ASC)   692 - 702   2010.12

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  • SSIM Image Quality Metric for Denoised Images Reviewed

    Peter Ndajah, Hisakazu Kikuchi, Masahiro Yukawa, Hidenori Watanabe, Shogo Muramatsu

    Proc. of 2010 WSEAS Int. Conf. on Visualization, Imaging and Simulation?(VIS’10)   53 - 58   2010.11

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  • A Computer-Aided Distinction Method of Borderline Grades of Oral Cancer Reviewed

    Mustafa M. Sami, Masahisa Saito, Shogo Muramatsu, Hisakazu Kikuchi, Takashi Saku

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E93A ( 8 )   1544 - 1552   2010.8

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    We have developed a new computer-aided diagnostic system for differentiating oral borderline malignancies in hematoxylin-eosin stained microscopic images. Epithelial dysplasia and carcinoma in-situ (CIS) of oral mucosa are two different borderline grades similar to each other, and it is difficult to distinguish between them. A new image processing and analysis method has been applied to a variety of histopathological features and shows the possibility for differentiating the oral cancer borderline grades automatically. The method is based on comparing the drop-shape similarity level in a particular manually selected pair of neighboring rete ridges. It was found that the considered similarity level in dysplasia was higher than those in epithelial CIS, of which pathological diagnoses were conventionally made by pathologists. The developed image processing method showed a good promise for the computer-aided pathological assessment of oral borderline malignancy differentiation in clinical practice.

    DOI: 10.1587/transfun.E93.A.1544

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  • An Optimum Design of Error Diffusion Filters Using the Blue Noise in All Graylevels Reviewed

    Junghyeun Hwang, Hisakazu Kikuchi, Shogo Muramatsu, Jaeho Shin

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E93A ( 8 )   1465 - 1475   2010.8

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    The error diffusion filter in this paper is optimized with respect to the ideal blue noise pattern corresponding to a single tone level. The filter coefficients are optimized by the minimization of the squared error norm between the Fourier power spectra of the resulting halftone and the blue noise pattern. During the process of optimization, the binary pattern power spectrum matching algorithm is applied with the aid of a new blue noise model. The number of the optimum filters is equal to that of different tones. The visual fidelity of the bilevel halftones generated by the error diffusion filters is evaluated in terms of a weighted signal-to-noise ratio, Fourier power spectra, and others. Experimental results have demonstrated that the proposed filter set generates satisfactory bilevel halftones of grayscale images.

    DOI: 10.1587/transfun.E93.A.1465

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  • Tone-Aware Halftoning Using Optimized Error Diffusion Filters Based on Blue Noise Patterns Reviewed

    Junghyeun Hwang, Hisakazu Kikuchi, Shogo Muramatsu

    Journal of Signal Processing   14 ( 4 )   301 - 304   2010.7

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  • Design of Error Diffusion Filter Using Lagrangian Optimization for Digital Halftoning Reviewed

    Junghyeun Hwang, Hisakazu Kikuchi, Shogo Muramatsu, Jaeho Shin

    Proc. of 2010 25th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   2010.7

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  • Total Variation Image Denoising Reviewed

    Peter Ndajah, Hisakazu Kikuchi, Shogo Muramatsu

    Proc. of 2010 International Conference on Approximation Theory   2010.3

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  • A Tone-Aware Halftoning Using Optimized Error Diffusion Filters Based on The Blue Noise Masks Reviewed

    Junghyeun Hwang, Hisakazu Kikuchi, Shogo Muramatsu

    Proc. of 2010 RISP Int. Workshop on Nonlinear Circuits, Communications and Signal Processing (NCSP)   2010.3

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  • Twin-pair rete ridge analysis: a computer-aided method for facilitating objective histopathological distinction between epithelial dysplasia and carcinoma in-situ of the oral mucosa Reviewed

    Mustafa M. Sami, Masahisa Saito, Shogo Muramatsu, Toshihiko Mikami, Kamal Al-Eryani, Jun Cheng, Faleh A. Sawair, Rasha Abu Eid, Hisakazu Kikuchi, Takashi Saku

    Oral Medicine & Pathology   14 ( 3 )   81 - 89   2010.1

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    DOI: 10.3353/omp.14.89

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  • Theoretical analysis of trend vanishing moments for directional orthogonal transforms Reviewed

    Shogo Muramatsu, Dandan Han, Tomoya Kobayashi, Hisakazu Kikuchi

    28th Picture Coding Symposium, PCS 2010   130 - 133   2010

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    This work contributes to investigate theoretical properties of the trend vanishing moment (TVM) which the authors have defined in a previous work and applied to the directional design of 2-D nonsep-arable GenLOTs. The TVM condition can be regarded as a natural extention of 1-D VM to 2-D one and alternative of the conventional directional vanishing moment (DVM). Firstly, the definition of TVM is given to clarify what it is, and then the mathematical meaning is discussed. While the conventional DVM condition requires for the moments to vanish along lines in the frequency domain and restricts the direction to a rational factor, the TVM condition imposes the moments only point-wisely and the direction can be steered flexibly. Some significant properties of TVMs are also shown and a simulation result of zonal coding for an artifical picture is given to verify the trend surface annihilation property. © 2010 IEEE.

    DOI: 10.1109/PCS.2010.5702440

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  • Interval Calculation of EM Algorithm for GMM Parameter Estimation Reviewed

    Hidenori Watanabe, Shogo Muramatsu, Hisakazu Kikuchi

    2010 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS   2686 - 2689   2010

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    This work proposes a low complexity computation of EM algorithm for Gaussian mixture model(GMM) and accelerates the parameter estimation. In previous works, the authors revealed that the computational complexity of GMM-based classification can be reduced by using an interval calculation technique[1], [2]. This work applies the idea to EM algorithm for GMM parameter estimation. From experiments, it is confirmed that the computational speed of the proposal achieves more than twice that of the standard method with &apos;exp( )&apos; function. The relative errors are less than 0.6% and 0.053% when the number of bits for table addressing are 4 and 8, respectively.

    DOI: 10.1109/ISCAS.2010.5537044

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  • 2-D NON-SEPARABLE GENLOT WITH TREND VANISHING MOMENTS Reviewed

    Tomoya Kobayashi, Shogo Muramatsu, Hisakazu Kikuchi

    2010 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING   385 - 388   2010

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    A novel design method of 2-D non-separable linear-phase paraunitary filter banks (LPPUFBs) is proposed. The trend vanishing moment (TVM) condition is newly derived for the lattice structure. The TVM condition can be regarded as a natural extension of 1-D VM to 2-D one and alternative of the conventional directional vanishing moments(DVMs). The structure is based on the 2-D DCT and can be regarded as an extension of GenLOT to the 2-D non-separable case. Because of the non-separability, the bases are allowed to be anisotropic and directional in addition to the fixed-subsampling, overlapping, orthogonal, real-valued, symmetric and compact-support property. As a previous work, the authors have shown that the block-wise implementation is appealing for the image processing application since the technique serves boundary operation for size-limitation, seamless basis alteration and compatibility with the block DCT. This work further contributes to yield the TVM condition so that piece-wise smooth images with smooth contours are compactly approximated. The condition is imposed directly on the design parameters and, therefore, the desirable properties of the lattice structure are maintained. From an experimental result of coding, it is shown that the TVM condition gives smooth reconstruction of a diagonal texture image.

    DOI: 10.1109/ICIP.2010.5654186

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  • Reversible component transforms by the LU factorization Reviewed

    Hisakazu Kikuchi, Junghyeun Hwang, Shogo Muramatsu, Jaeho Shin

    28th Picture Coding Symposium, PCS 2010   238 - 241   2010

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    A scaled transform is defined for a given irreversible linear transformation based on the LU factorization of a nonsingular matrix so that the transformation may be computed in a lifting form and hence may be reversible. Round-off errors in the lifting computation and the computational complexity are analyzed. Some reversible component transforms are presented and experimented to give some remarks to image compression applications. Discussions are developed with coding gain and actual bit rates. © 2010 IEEE.

    DOI: 10.1109/PCS.2010.5702475

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  • Effective Features and a Classification System for Defective Soldering Detection Reviewed

    Kentaro Sugiyama, Tatsuya Miyaguchi, Hisakazu Kikuchi, Shogo Muramatsu, Jun-ichi Kobayashi

    Proc. of 2009 International Workshop on Smart Info-Media Systems in Asia (SISA)   2009.10

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  • Bit-Plane Coding with a New Context Modeling for Applications to High-Quality Images Reviewed

    Hisakazu Kikuchi, Minoru Hiki, Shogo Muramatsu

    Proc. of 2009 International Workshop on Smart Info-Media Systems in Asia (SISA)   160 - 165   2009.10

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  • Histopathological Image Analysis for the Aid in Diagnosis of Oral Borderline Malignancies Reviewed

    Kyosuke Satoh, Mustafa M. Sami, Hisakazu Kikuchi, Shogo Muramatsu, Takashi Saku

    Proc. of 2009 International Workshop on Smart Info-Media Systems in Asia (SISA)   106 - 110   2009.10

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  • Multiplierless Refinement Scheme for Interval Calculation of GMM-Based Classification Reviewed

    Hidenori Watanabe, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2009 Asia-Pacific Signal and Information Processing Association Annual Summit and Conference (APSIPA ASC)   282 - 285   2009.10

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  • Simple Bit-plane Coding Conditioned by Expectation Values of Pixels for Lossy-to-Lossless Image Compression Reviewed

    Hisakazu Kikuchi, Shogo Muramatsu

    Proc. of 2009 24th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   393 - 396   2009.7

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  • Digital Halftoning Using an Error Diffusion Filter Optimized for the Blue Noise in Every Uniform Tone Reviewed

    Junghyeun Hwang, Hisakazu Kikuchi, Shogo Muramatsu, Jaeho Shin

    Proc. of 2009 24th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   227 - 230   2009.7

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  • Constraints of Second-Order Vanishing Moments on Lattice Structures for Non-separable Orthogonal Symmetric Wavelets Reviewed

    Atsuyuki Adachi, Shogo Muramatsu, Hisakazu Kikuchi

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E92A ( 3 )   788 - 797   2009.3

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    In this paper, a design method of two-dimensional (2D) orthogonal symmetric wavelets is proposed by using a lattice structure for multi-dimensional (M-D) linear-phase paraunitary filter banks (LPPUFB), which the authors have proposed as a previous work and then modified by Lu Gan et al. The derivation process for the constraints on the second-order vanishing moments is shown and some design examples obtained through optimization with the constraints are exemplified. In order to verity the significance of the constraints, some experimental results are shown for Lena and Barbara image.

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  • SIMPLE BIT-PLANE CODING FOR LOSSLESS IMAGE COMPRESSION AND EXTENDED FUNCTIONALITIES Reviewed

    Hisakazu Kikuchi, Kunio Funahashi, Shogo Muramatsu

    PCS: 2009 PICTURE CODING SYMPOSIUM   361 - 364   2009

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    A simple lossy-to-lossless bit-plane coding of still images is presented to integrate several functionality extensions including selective the partitioning, progressive transmission, ROI transmission, accuracy scalability, and others. The mean squared error between the original image and a decoded image at any progression level is known prior to encoding/decoding. The proposed bit-plane codec is competitive with JPEG-LS and JPEG 2000 in the lossless compression of 8-bit grayscale and 24-bit color images. The codec outperforms the existing standards in 8-bit color-quantized image compression.

    DOI: 10.1109/PCS.2009.5167351

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  • BLOCK-WISE IMPLEMENTATION OF DIRECTIONAL GENLOT Reviewed

    Shogo Muramatsu, Minoru Hiki

    2009 16TH IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING, VOLS 1-6   3977 - 3980   2009

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    This paper introduces block-wise implementation of 2-D nonseparable linear-phase paraunitary filter banks (LPPUFB) and shows a directional design approach. As a previous work, the authors have proposed a lattice structure of non-separable LPPUFBs which guarantees both of the linear-phase and orthogonal property. This paper shows that the structure serves variability of basis images without any violation to the orthogonality. Consequently, a boundary operation for size-limitation is yielded and compatibility with the 2-D separable block-DCT becomes possible since the lattice structure is based on the block-DCT. The main advantage of non-separable systems is its directional capability, and it is allowed to produce a directional non-separable GenLOT. Although the adaptive control of basis images is under investigation, experimental results of texture coding show prospective significance of the directional GenLOT.

    DOI: 10.1109/ICIP.2009.5413823

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  • Motion-compensated spatio-temporal nonseparable filtering for scalable video coding Reviewed

    Minoru Hiki, Shogo Muramatsu, Hisakazu Kikuchi

    Kyokai Joho Imeji Zasshi/Journal of the Institute of Image Information and Television Engineers   63 ( 11 )   1604 - 1610   2009

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    The use of a novel motion compensated spatio-temporal nonseparable filter (MCSTF) is proposed for scalable video coding. This filter is an alternative to the present motion-compensated temporal filtering (MCTF), a fundamental component for scalable video coding in the next generation. MCTF improve the coding efficiency and provide the temporal scalability. We classify MCSTF as a non-separable sub-sampling version of MCTF, and it provides interlaced pictures as intermediate video sequence by using a spatio-temporal split process. Furthermore, its 1/3-transform structure, which excludes the lifting-update-step, significantly suppresses the PSNR fluctuation that occurs when the existing MCTF technique is used. Our proposed system suppresses PSNR fluctuation with a higher average PSNR than the existing MCTF. Two types of sub-sampling lattices were investigated: the vertical-temporal (VT) quincunx and the face-centered orthorhombic (FCO) ones. Experimental results with entropy coded scalar quantization show the signifaicance of our proposed technique.

    DOI: 10.3169/itej.63.1604

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  • Two-Degree Vanishing Moments on 2-D Non-separable GenLOT Reviewed

    Tomoya Kobayashi, Shogo Muramatsu, Hisakazu Kikuchi

    2009 INTERNATIONAL SYMPOSIUM ON INTELLIGENT SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ISPACS 2009)   248 - 251   2009

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    This paper proposes a novel design method of two-dimensional (2-D) non-separable linear-phase paraunitary filter banks (LPPUFB). The two-degree vanishing moment constraint is derived for the lattice structure. In the 2 x 2-decomposition case, the authors have already derived the constraint and designed non-separable symmetric orthonormal wavelets with two-degree vanishing moments. This work extends the discussion to more general 2m(y) x 2m(x)-decomposition case and yields a method to impose the condition to the lattice structure. The constraint is imposed directly on design parameters so that both of the linear-phase and paraunitary property are structurally guaranteed. It is shown that the two-degree vanishing moment constraint reduces the number of parameters to be freely chosen and gives a smooth lowpass filter. Several design examples are shown to verify the significance of the novel constraint on the lattice structure.

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  • Visual Fidelity of Bilevel Halftones Generated by the Error Diffusion Filter Optimized for the Blue Noise Masks in All Tone Levels Reviewed

    Junghyeun Hwang, Hisakazu Kikuchi, Shogo Muramatsu, Jaeho Shin

    2009 INTERNATIONAL SYMPOSIUM ON INTELLIGENT SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ISPACS 2009)   371 - +   2009

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    In this paper a set of the optimum error diffusion filters is presented for the bilevel halftoning of grayscale images and the visual fidelity of the bilevel halftones generated by the error diffusion filters is investigated. The error diffusion filter is optimized with respect to the ideal blue noise mask (BNM) corresponding to a single tone level. The number of the optimum filters is hence equal to that of different tones. The filter coefficients are optimized by the minimization of the squared error norm between the frequency response of the filter and the Fourier spectrum of the BNM. During the process of optimization, the binary pattern power spectrum manipulation algorithm (BIPPSMA) is applied. Visual fidelity of the bilevel halftones generated by the error diffusion filters is investigated in terms of a weighted signal-to-noise ratio (WSNR) and Fourier power spectra. Experimental results have demonstrated that the proposed filter set generates satisfactory bilevel halftones of grayscale images.

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  • FAST ALGORITHM FOR GMM-BASED PATTERN CLASSIFIER Reviewed

    Shogo Muramatsu, Hidenori Watanabe

    2009 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH, AND SIGNAL PROCESSING, VOLS 1- 8, PROCEEDINGS   633 - 636   2009

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    This work proposes a fast decision algorithm in pattern classification based on Gaussian mixture models (GMM). Statistical pattern classification problems often meet a situation that comparison between probabilities is obvious and involve redundant computations. When GMM is adopted for the probability model, the exponential function should be evaluated. This work firstly reduces the exponential computations to simple and rough interval calculations. The exponential function is realized by scaling and multiplication with powers of two so that the decision is efficiently realized. For finer decision, a refinement process is also proposed. In order to verify the significance, experimental results on TI DM6437 EVM board are shown through the application to a skin-color extraction problem. It is verified that the classification was almost completed without any refinement process and the refinement process can proceed the residual decisions.

    DOI: 10.1109/ICASSP.2009.4959663

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  • Lossless-by-Lossy Coding for Scalable Lossless Image Compression Reviewed

    Kazuma Shinoda, Hisakazu Kikuchi, Shogo Muramatsu

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E91A ( 11 )   3356 - 3364   2008.11

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    This paper presents a method of scalable lossless image compression by means of lossy coding. A progressive decoding capability and a full decoding for the lossless rendition are equipped with the losslessly encoded bit stream. Embedded coding is applied to large-amplitude coefficients in a wavelet transform domain. The other wavelet coefficients are encoded by a context-based entropy coding. The proposed method slightly outperforms JPEG-LS in lossless compression. Its rate-distortion performance with respect to progressive decoding is close to that of JPEG2000. The spatial scalability with respect to resolution is also available.

    DOI: 10.1093/ietfec/e91-a.11.3356

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  • Functionally layered video coding for water level monitoring Reviewed

    Sakol Udomsiri, Masahiro Iwahashi, Shogo Muramatsu

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E91A ( 4 )   1006 - 1014   2008.4

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    This paper proposes a new type of layered video coding especially for the use of monitoring water level of a river. A sensor node of the system decomposes an input video signal into some kinds of component signals and produces a bit stream functionally separated into three layers. The first layer contains the minimum components effective for detecting the water level. It is transmitted at very low bit rate for regular monitoring. The second layer contains signals for thumb-nail video browsing. The third layer contains additional data for decoding the original video signal. These are transmitted in case of necessity. A video signal is decomposed into several bands with the three dimensional Haar transform. In this paper, optimum bands to be contained into the 1st layer are experimentally investigated considering both of water level detection and data size to be transmitted. As a result, bit rate for transmitting the first layer is reduced by 32.5% at the cost of negligible 3.7% decrease of recognition performance for one of video examples.

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  • Color demosaicing using asymmetric directional interpolation and hue vector smoothing Reviewed

    Yoshihisa Takahashi, Kentaro Hiraki, Hisakazu Kikuchi, Shogo Muramatsu

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E91A ( 4 )   978 - 986   2008.4

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    This paper presents a color demosaicing method applied to the Bayer pattern color filter array (CFA). Reliable estimation of an edge direction, edge-directed asymmetric interpolation, and the use of color samples at immediate neighbors are considered as the key guidelines for smooth and sharp image restoration. Also, special interest is directed to local areas that are rich in high spatial frequency variations. For suppression of false colors likely to occur in those areas, a hue vector representation is introduced so that the spatial correlation between different color components may be exploited in consistent with the local constant-hue principle. Smoothing is repeated in the hue vector field a few times. Experimental results have shown preferable performances in terms of PSNR, CIELAB color difference, hue angle difference, CIE chromaticity and visual appearance, in particular resulting in less false colors.

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  • Luma-based directional copy interpolation for color bilevel AM halftoning for printing Reviewed

    Hisakazu Kikuchi, Akira Iijima, Shogo Muramatsu, Shigenobu Sasaki

    IEICE ELECTRONICS EXPRESS   5 ( 5 )   170 - 175   2008.3

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    The interpolation of color pixel values prior to digital halftoning is discussed and a new color interpolation scheme is presented by a directional copy of color values in the gradient field of luma. Error diffusion quantization is combined with clustered-dot ordered dithering to prevent from contouring. Experimental results demonstrate that sharp and false color-free interpolation is obtained to produce color bilevel AM halftones with weak rosettes and no contouring artifacts.

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  • Orthogonality of DWT and Correlation of Distortion Reviewed

    Shogo Muramatsu, Atsuyuki Adachi, Minoru Hiki, Hisakazu Kikuchi

    Proc. of 2007 26th Picture Coding Symposium (PCS)   2007.11

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  • Equivalent parallel structure of deinterlacer banks and its application to optimal bit-rate allocation Reviewed

    Minoru Hiki, Shogo Muramatsu, Takuma Ishida, Hisakazu Kikuchi

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E90A ( 3 )   642 - 650   2007.3

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    In this paper, theoretical properties of deinterlacer banks are analyzed. Deinterlacer banks are novel filter banks in the sense that a progressive video sequence is separated into two progressive video sequences of a half frame rate and, furthermore, interlaced sequences are produced as intermediate data. Unlike the conventional filter banks, our deinterlacer banks are constructed in a way unique to multidimensional systems by using invertible deinterlacers, which the authors have proposed before. The system is a kind of shift-varying filter banks and it was impossible to derive the optimal bit-allocation control without any equivalent parallel filter banks. This paper derives an equivalent polyphase matrix representation of the whole system and its equivalent parallel structure, and then shows the optimal rate allocation for the deinterlacer banks. Some experimental results justify the effectiveness of the optimal rate allocation through our theoretical analysis.

    DOI: 10.1093/ietfec/e90-a.3.642

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  • Water Level Tracking with CONDENSATION Algorithm Reviewed

    Shinsuke Kobayashi, Shogo Muramatsu, Hisakazu Kikuchi, Masahiro Iwahashi

    Proc. of 2007 International Workshop on Advanced Image Technology (IWAIT)   750 - 755   2007.1

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  • Scalable Lossless Color Image Compression by a Lossless-By-Lossy Approach Reviewed

    Hisakazu Kikuchi, Kazuma Shinoda, Shogo Muramatsu

    Proc. of 2007 International Workshop on Advanced Image Technology (IWAIT)   789 - 794   2007.1

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  • Water level detection for functionally layered video coding Reviewed

    Masahiro Iwahashi, Sakol Udomsiri, Yuji Imai, Shogo Muramatsu

    2007 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING, VOLS 1-7   885 - +   2007

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    This paper proposes a new type of layered video coding especially for the use of monitoring a river or a water channel. A sensor node of the system decomposes a video signal into some components and produces a bit stream which is functionally separated into three layers. The first layer contains the minimum components effective for detecting water level. The second layer contains signals for thumb-nail video browsing. Each of them is transmitted at very low bit rate for regular monitoring. The third layer contains additional data for decoding the original video signal. It is transmitted in case of necessity. The original video signal is decomposed into band signals as the components by the Haar transform in a sensor node. Experimental results show which band signals should be included into the first layer considering both of water level detection performance and data size to be transmitted.

    DOI: 10.1109/ICIP.2007.4379157

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  • Color demosaicing that takes care of local areas rich in high spatial frequencies Reviewed

    Kentaro Hiraki, Yoshihisa Takahashi, Hisakazu Kikuchi, Shogo Muramatsu

    Kyokai Joho Imeji Zasshi/Journal of the Institute of Image Information and Television Engineers   61 ( 8 )   1209 - 1217   2007

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    A color demosaicing method has been developed that effectively performs within local areas that are rich in high spatial frequency variations. Such areas are likely to cause strong artifacts after demosaicing because of the inherent difficulty in subsampling. In visually tolerable image restoration, the spatial correlation between different color components is exploited to consistently maintain favorable transitions in the component intensities. Missing primary color values on the Bayer pattern color filter array are estimated using an edge-directed interpolation of primary color difference signals. The local transitions of the primary color differences are then smoothed by spatially adaptive filtering. Experimental results showed objectively-good and visually-preferable performance in terms of PSNR, CIELAB color difference and visual appearance, particularly resulting in less false color.

    DOI: 10.3169/itej.61.1209

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  • Parameter embedding in motion-JPEG2000 through ROI for variable-coefficient invertible deinterlacing Reviewed

    Jun Uchita, Shogo Muramatsu, Takuma Ishida, Hisakazu Kikuchi

    IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS   E89D ( 11 )   2794 - 2801   2006.11

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    In this paper, a coefficient-parameter embedding method into Motion-JPEG2000 (MJP2) is proposed for invertible deinterlacing with variable coefficients. Invertible deinterlacing, which the authors have developed before, can be used as a preprocess of frume-based motion picture codec, such as MJP2, for interlaced videos. When the conventional field-interleaving is used instead, comb-tooth artifacts appear around edges of moving objects. On the other hand, the invertible deinterlacing technique allows us to suppress the comb-tooth artifacts and also guaranties recovery of original pictures. As previous works, the authors have developed a variable coefficient scheme with a motion detector, which realizes adaptability to local characteristics of given pictures. However, when this deinterlacing technique is applied to a video codec, coefficient parameters have to be sent to receivers for original picture recovery. This paper proposes a parameter-embedding technique in MJP2 and constructs a standard stream Which consists both of picture data and the parameters. The parameters are embedded into the LH1 component of wavelet transform domain through the ROI (region of interest) function of JPEG2000 without significant loss in the performance of comb-tooth suppression. Some experimental results show the feasibility of our proposed scheme.

    DOI: 10.1093/ietisy/e89-d.11.2794

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  • Two-Stage Lossless Image Compression by Wavelet-Based Lossy Coding Reviewed

    Kazuma Shinoda, Hisakazu Kikuchi, Shogo Muramatsu

    Proc. of 2006 21st International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   325 - 328   2006.7

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  • Active Contour Description with Curvature Scale Space(CSS) for Video Retrieval Reviewed

    Shinsuke Kobayashi, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2006 International Workshop on Advanced Image Technology (IWAIT)   2006.1

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  • Iterative asymmetric average interpolation for color demosaicing of single-sensor digital dcamera data Reviewed

    Y Takahashi, H Kikuchi, S Muramatsu, N Mizutani

    DIGITAL PHOTOGRAPHY II   6069   606907   2006

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    A two-step color demosaicing algorithm for Bayer-pattern mosaic images is presented. Missing primary colors are at first estimated by an asymmetric average interpolation, and then sharpness of the initial estimate is improved by an iterative procedure. The intensity variation along an edge is not always uniform along one direction and its opposite with respect to a target pixel to be interpolated. Spatially asymmetric averaging along an edge is hence introduced in this study, where less intensity variation is assumed to be of stronger significance in the sense of stable restoration for details. Also, we restrict ourselves to use short-kernel filters for sharpness recovery. Spatially-adaptive filtering is involved with color demosaicing and an optical system for image acquisition and color filter array (CFA) sampling are subjected to the spatio-temporal aperture effect. Hence it is unavoidable to produce a blurred restoration to some extent. In order to overcome these difficulties and to restore a sharp image, an iterative procedure is introduced. Experimental results have shown a favorable performance in terms of objective measures such as PSNR and CIELAB color difference and subjective visual appearances, especially in sharpness recovery.

    DOI: 10.1117/12.650446

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  • A lossless-by-lossy approach to lossless image compression Reviewed

    Kazuma Shinoda, Hisakazu Kikuchi, Shogo Muramatsu

    2006 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING, ICIP 2006, PROCEEDINGS   2265 - +   2006

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    This paper proposes a method of lossless image coding by the aid of lossy image coding. It aims at an improvement in the compression efficiency. We apply a kind of embedded coding to large coefficients in magnitude in a wavelet transform domain. The other wavelet coefficients are encoded by a context-based entropy coding. The result slightly outperforms the compression efficiency in JPEG-LS.

    DOI: 10.1109/ICIP.2006.312814

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  • Suppression of PSNR fluctuation in motion-compensated temporal 1/3-transform through non-separable sub-sampling Reviewed

    Minoru Hiki, Takuma Ishida, Shogo Muramatsu, Hisakazu Kikuchi

    2006 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING, ICIP 2006, PROCEEDINGS   2153 - +   2006

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    In this work, a novel motion compensated spatio-temporal filter (MCSTF) is proposed for scalable video coding. MCSTF is an alternative technique of existing motion-compensated temporal filtering (MCTF), a fundamental component for scalable video coding in next generation. MCSTF is a non-separable sub-sampling version of MCTF and provides interlaced pictures as intermediate video sequence by using a spatio-temporal split process. Furthermore, the 1/3-transform structure, which excludes the lifting-update-step, significantly suppresses the PSNR fluctuation which occurs in the existing MCTF technique. Our proposed system has an advantage of suppressing PSNR fluctuation with almost the same average PSNR as that of existing MCTF. In this paper, two types of sub-sampling lattices are investigated: the vertical-temporal (VT) quincunx and face-centered orthorhombic (FCO) lattices. Some experimental results with entropy coded scalar quantization show the significance of our proposed technique.

    DOI: 10.1109/ICIP.2006.312870

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  • Motion-JPEG2000 codec compensated for interlaced scanning videos Reviewed

    T Ishida, S Muramatsu, H Kikuchi

    IEEE TRANSACTIONS ON IMAGE PROCESSING   14 ( 12 )   2179 - 2191   2005.12

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    This paper presents an implementation scheme of Motion-JPEG2000 (MJP2) integrated with invertible deinterlacing. In previous work, we developed an invertible deinterlacing technique that suppresses the comb-tooth artifacts which are caused by field interleaving for interlaced scanning videos, and affect the quality of scalable frame-based codecs, such as MJP2. Our technique has two features, where sampling density is preserved and image quality is recovered by an inverse process. When no codec is placed between the deinterlacer and inverse process, the original video is perfectly reconstructed. Otherwise, it is almost completely recovered. We suggest an application scenario of this invertible deinterlacer for enhancing the sophisticated signal-to-noise ratio scalability in the frame-based MJP2 coding. The proposed system suppresses the comb-tooth artifacts at low bitrates, while enabling the quality recovery through its inverse process at high bitrates within the standard bitstream format. The main purpose of this paper is to present a system that yields high quality recovery for an MJP2 codec. We demonstrate that our invertible deinterlacer can be embedded into the discrete wavelet transform employed in MJP2. As a result, the energy gain factor to control rate-distortion characteristics can be compensated for optimal compression. Simulation results show that the recovery of quality is improved by, for example, more than 2.0 dB in peak signal-to-noise ratio by applying our proposed gain compensation when decoding 8-bit grayscale Football sequence at 2.0 bpp.

    DOI: 10.1109/TIP.2005.857255

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  • A new color demosaicing method using asymmetric average interpolation and its iteration Reviewed

    Y Takahashi, H Kikuchi, S Muramatsu, N Mizutani

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E88A ( 8 )   2108 - 2116   2005.8

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    This paper presents a color demosaicing method by introducing iterative asymmetric average interpolation. Missing primary colors on a Bayer pattern color filter array (CFA) are estimated by an asymmetric average interpolation where less intensity variation is assumed to be of stronger significance, before sharpness of an initial estimate is further improved by an iterative procedure. The iteration is implemented by an observation process followed by a restoration process. The former is modeled by blurring followed by CFA sampling and the latter is completely as same as the color demosaicing method initially applied. Experimental results have shown a favorable performance in terms of PSNR and visual appearance, in particular, in sharpness recovery.

    DOI: 10.1093/ietfec/e88-a.8.2108

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  • Mathematical Properties of Deinterlacer Banks Reviewed

    Minoru Hiki, Shogo Muramatsu, Takuma Ishida, Hisakazu Kikuchi

    Proc. of 2005 20th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   1005 - 1006   2005.7

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  • Iterative Asymmetric Average Interpolation for a Single CCD Mosaic Image Invited Reviewed

    Yoshihisa Takahashi, Hisakazu Kikuchi, Shogo Muramatsu, Naoki Mizutani

    Proc. of 2005 20th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   199 - 200   2005.7

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  • Spatio-Temporal Multi-Resolution Analysis through Hierarchical Deinterlacer Banks Reviewed

    Takuma Ishida, Shogo Muramatsu, Jun Uchita, Daisuke Kitagawa, Hisakazu Kikuchi

    Proc. of 2005 International Workshop on Advanced Image Technology (IWAIT)   2005.1

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  • Two-Step Detection of Video Shot Boundaries in a Wavelet Transform Domain Reviewed

    Satoshi Hasebe, Shogo Muramatsu, Hisakazu Kikuchi, Makoto Nagumo

    Journal of the Institute of Image Electronics Engineers of Japan   34 ( 1 )   17 - 26   2005

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    This paper presents a two-step algorithm for detecting video shot boundaries in a wavelet transform domain. It captures gradual shot transitions such as dissolves and fades as well as abrupt shot transitions such as cuts. At the first step, it computes a distance between video intervals to find an isolated interval. Then, at the second step, it computes a distance between frames to specify the exact location of a shot boundary. Its effectiveness is evaluated in terms of recall and precision. © 2005, The Institute of Image Electronics Engineers of Japan. All rights reserved.

    DOI: 10.11371/iieej.34.17

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  • Lossless implementation of motion JPEG2000 integrated with invertible deinterlacing Reviewed

    Takuma Ishida, Shogo Muramatsu, Hisakazu Kikuchi

    Proceedings - IEEE International Symposium on Circuits and Systems   6328 - 6331   2005

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    A lossless implementation technique of Motion JPEG2000 (MJP2) integrated with invertible deinterlacing is presented. In previous works, we developed an invertible deinterlacing technique that suppresses the comb-tooth artifacts, which are caused by field interleaving of interlaced videos and affect the quality of scalable intraframe-based coding such as MJP2. We suggested a scenario of applying the technique as a prefilter to intraframe-based coding systems. This system suppresses the comb-tooth artifacts, while guaranteeing recovery of the original quality through the inverse process. In this work, we further propose an exact lossless implementation technique by embedding the deinterlacer into MJP2 and modifying header information for appropriate decoding. We demonstrate that the comb-tooth suppression capability can be kept at low bitrates with the standard MJP2 decoder. The experiments also show that the overhead of our proposed method is less than 0.9% compared with the normal field interleaving. © 2005 IEEE.

    DOI: 10.1109/ISCAS.2005.1466088

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  • Lossless implementation of motion JPEG2000 integrated with invertible deinterlacing Reviewed

    T Ishida, S Muramatsu, H Kikuchi

    2005 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS (ISCAS), VOLS 1-6, CONFERENCE PROCEEDINGS   6328 - 6331   2005

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    A lossless implementation technique of Motion JPEG2000 (MJP2) integrated with invertible deinterlacing is presented. In previous works, we developed an invertible deinterlacing technique that suppresses the comb-tooth artifacts, which are caused by field interleaving of interlaced videos and affect the quality of scalable intraframe-based coding such as MJP2. We suggested a scenario of applying the technique as a prefilter to intraframe-based coding systems. This system suppresses the comb-tooth artifacts, while guaranteeing recovery of the original quality through the inverse process. In this work, we further propose an exact lossless implementation technique by embedding the deinterlacer into MJP2 and modifying header information for appropriate decoding. We demonstrate that the comb-tooth suppression capability can be kept at low bitrates with the standard MJP2 decoder. The experiments also show that the overhead of our proposed method is less than 0.9% compared with the normal field interleaving.

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  • Performance evaluation of spatio-temporal multi-resolution analysis with deinterlacer banks Reviewed

    T Ishida, S Muramatsu, D Kitagawa, J Uchita, M Hiki, H Kikuchi

    VISUAL COMMUNICATIONS AND IMAGE PROCESSING 2005, PTS 1-4   5960   177 - 188   2005

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    In this work, hierarchical motion compensated three-dimensional (3-D) filter banks for spatio-temporal multiresolution analysis are presented as new tools for scalable video format control. For recent developments in scalable video coding, most of them are based on 3-D wavelet transform with motion compensation. To achieve the function of frame-rate and spatial resolution scalabilities, motion compensated temporal filtering (MCTF) through lifting wavelet transform currently attracts many researchers as an effective temporal decomposition tool. As previous works, we proposed single stage deinterlacer banks as novel 3-D filter banks. Unlike other filter banks, our proposed system is constructed in a way unique to multi-dimensional systems by using invertible deinterlacers, which we have proposed before. The single stage deinterlacer banks decompose a progressive video into two subband sequences of a half frame-rate in the progressive scanning manner. Even though the system handles interlaced videos as intermediate data, introducing a multistage decomposition is simply achieved because the output sequences have also the progressive format as like the input. Our proposed hierarchical deinterlacer banks are accompanied by 2-D discrete wavelet transforms (DWT) as spatial transforms. The multistage technique provides interlaced sequences as well as several reduced-rate progressive sequences while maintaining the reconstruction of the original full-resolution full-rate video sequence. We show that fine granular control of spatio-temporal resolution can be achieved through the hierarchical process. Some experimental results show novel functions and the significance of the proposed filter banks.

    DOI: 10.1117/12.631544

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  • Constructing storyboards based on hierarchical clustering analysis Reviewed

    S Hasebe, MM Sami, S Muramatsu, H Kikuchi

    VISUAL COMMUNICATIONS AND IMAGE PROCESSING 2005, PTS 1-4   5960   437 - 445   2005

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    There are growing needs for quick preview of video contents for the purpose of improving accessibility of video archives as well as reducing network traffics. In this paper, a storyboard that contains a user-specified number of keyframes is produced from a given video sequence. It is based on hierarchical cluster analysis of feature vectors that are derived from wavelet coefficients of video frames. Consistent use of extracted feature vectors is the key to avoid a repetition of computationally-intensive parsing of the same video sequence. Experimental results suggest that a significant reduction in computational time is gained by this strategy.

    DOI: 10.1117/12.631385

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  • Lossless compression of Motion JPEG2000 integrated with invertible deinterlacing Reviewed

    Takuma Ishida, Shogo Muramatsu, Hisakazu Kikuchi

    Kyokai Joho Imeji Zasshi/Journal of the Institute of Image Information and Television Engineers   59 ( 7 )   1011 - 1019   2005

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Inst. of Image Information and Television Engineers  

    A lossless implementation technique of Motion JPEG2000 (MJP2) integrated with invertible deinterlacing is presented in this paper. The invertible deinterlacing, which has been previously published, is a technique that suppresses the comb-tooth artifacts caused by field interleaving of interlaced videos and also guarantees the recovery of the original through the inverse process. The comb-tooth artifacts affect the performance of scalable intraframe-based codecs such as MJP2 and, thus we have suggested a scenario for applying this invertible deinterlacing as a prefilter to such a scalable codec since it is possible to suppress flickering due to the artifacts for low and middle bit-rate decoding and to remove the filtering effect for high quality decoding. In this work, we further propose an exact lossless implementation technique by integrating the deinterlacer into MJP2 codecs and modifying the header information for appropriate standard decoding. We demonstrate some simulation results to show that the comb-tooth suppression capability can be kept at low bitrates with standard MJP2 decoders. Furthermore, some experimental results show that the overhead of our proposed method is less than 2.0% compared with normal field interleaving in video sequence 'Football'.

    DOI: 10.3169/itej.59.1011

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  • Parameter transmission via ROI in JPEG2000 for variable-coefficient invertible deinterlacing. Reviewed

    Takuma Ishida, Jun Uchita, Shogo Muramatsu, Hisakazu Kikuchi, Tetsuro Kuge

    Proc. of 2004 12th European Signal Processing Conference (EUSIPCO), Vienna, Austria, September 6-10, 2004   653 - 656   2004.9

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  • Video key frame selection by clustering wavelet coefficients. Reviewed

    Satoshi Hasebe, Makoto Nagumo, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2004 12th European Signal Processing Conference (EUSIPCO), Vienna, Austria, September 6-10, 2004   2303 - 2306   2004.9

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  • Impact of Chip Duty-factor in DS-UWB Communications: Some Implications of Regulatory Emission Constraints Reviewed

    M. A. Rahman, Shigenobu Sasaki, Jie Zhou, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2004 7th International Symposium on Wireless Personal Multimedia Communications (WPMC)   3   233 - 237   2004.9

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  • Evaluation of selective rake receiver in direct sequence ultra wideband communications Reviewed

    MA Rahman, S Sasaki, J Zhou, S Muramatsu, H Kikuchi

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E87A ( 7 )   1742 - 1746   2004.7

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    Performance of selective Rake (SRake) receiver is evaluated for direct sequence ultra wideband (DS-UWB) communications considering an independent Rayleigh channel having exponentially decaying power delay profile (PDP). BEP performances are shown. The results obtained are compared with similar results in a channel having flat PDP. Assumption of a flat PDP is found to predict the optimum spreading bandwidth to be lower and sub-optimum operating performance beyond optimum spreading bandwidth to be severely worse than that is achievable in a channel having exponentially decaying PDP by employing an SRake receiver having fixed number of combined paths. Optimum spreading bandwidth for SRake in a channel having exponentially decaying PDP is shown to be much larger than the one in a channel having flat PDP; that is specifically a good-news for UWB communications. Effects of partial band interference are also investigated. Interference is found to be less effective in exponentially decaying PDP.

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  • Wavelet-Based Keyframe Selection Techniques for Video Abstraction Reviewed

    Satoshi Hasebe, Makoto Nagumo, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2004 19th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   416 - 419   2004.7

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  • Maximally-Decimated Perfect Reconstruction Deinterlacer Banks Based on FCO-Sampling Reviewed

    Daisuke Kitagawa, Takuma Ishida, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2004 19th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   863 - 866   2004.7

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  • Approximate Analyses and Comparisons of Generalized Spatial Correlation for Linear and Circular Antenna Arrays Reviewed

    Jie Zhou, Kenta Ishizawa, Shigenobu Sasaki, Shogo Muramatsu, Hisakazu Kikuchi, Yoshikuni Onozato

    Proc. of 2004 19th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   507 - 510   2004.7

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  • A parameter decimation technique for variable-coefficient invertible deinterlacing Reviewed

    J Uchita, T Ishida, S Muramatsu, H Kikuchi, T Kuge

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E87A ( 6 )   1363 - 1370   2004.6

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    In this paper, a coefficient-parameter reduction method is proposed for invertible deinterlacing with variable coefficients. Invertible deinterlacing, which the authors have developed before, can be used as a preprocess of frame-based motion picture codec, such as Motion-JPEG2000 (MJP2), for interlaced videos. When the conventional field-interleaving is used instead, comb-tooth artifacts appear around edges of moving objects. On the other hand, the invertible deinterlacing technique allows us to suppress the comb-tooth artifacts and also to recover an original picture on demand. As previous works, the authors have developed a variable coefficient scheme with a motion detection filter, which realizes adaptability to local characteristics of given pictures. When applying this deinterlacing technique to an image codec, it is required to send coefficient parameters to receivers for original picture recovery. This work proposes a parameter decimation technique and shows that this reduction approach can be achieved without significant loss of comb-tooth suppression capability and improves the quality at high bit-rate decoding.

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  • Online SNR and fading parameter estimation for parallel combinatorial SS systems in Nakagami fading channels Reviewed

    K Uenaga, S Sasaki, K Takizawa, J Zhou, S Muramatsu, H Kikuchi

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E87A ( 6 )   1495 - 1499   2004.6

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    This letter discusses the performance of online SNR estimation including fading parameter estimation for parallel combinatorial SS (PC/SS) systems. The PC/SS systems are partial-code-parallel multicode SS systems, which have high-rate data transmission capability. Nakagami-m distribution is assumed as fading channel model to cover a wide range of fading conditions. The SNR and fading parameter estimation considered in this letter is based on only a statistical ratio of correlator outputs at the receiver. Numerical results show that SNR estimation performance with fading parameter estimation is close to the one in the case of perfect fading parameter information, if the number of transmitting PN codes is less than a half of assigned PN codes.

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  • Invertible Deinterlacing with Variable Coefficients Reviewed

    Takuma Ishida, Shogo Muramatsu, Hisakazu Kikuchi, Tetsuro Kuge

    IEICE Trans. on Fundamentals   J87-A ( 2 )   336 - 341   2004.2

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    可変係数型可逆デインタレース処理を提案する.これまでに筆者らは,Motion-JPEG2000のようなフレーム内符号化で問題となるインタレース映像のくし状効果を抑えるために,可逆デインタレース処理を提案した.しかしながら,このデインタレースフィルタは固定係数であり,局所的には必ずしも適しているとはいえなかった.そこで,可逆性を犠牲にすることなく係数を可変とする新たな手法を提案し,画像の局所的性質に適した係数を用いることで画質の更なる改善を行う.シミュレーション結果により評価し,本手法の有効性を確認する.

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  • Generalized spatial correlation equations for antenna arrays in wireless diversity reception: Exact and approximate analyses Reviewed

    J Zhou, K Ishizawa, S Sasaki, S Muramatsu, H Kikuchi, Y Onozato

    IEICE TRANSACTIONS ON COMMUNICATIONS   E87B ( 1 )   204 - 208   2004.1

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    Multiple antenna systems are promising architectures for overcoming the effects of multi-path interference an increasing the spectrum efficiency. In order to be able to investigate these systems, in this article, we derive generalized spatial correlation equations of a circular antenna array for two typical angular energy distributions: a Gaussian angle distribution and uniform angular distribution. The generalized spatial correlation equations are investigated carefully by exact and approximate analyses.

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  • Generalized Spatial Correlation Equations for Antenna Array in Wireless Diversity Reception: Exact and Approximate Analyses Reviewed

    Jie Zhou, Kentas Ishizawa, Shigenobu Sasaki, Shogo Muramatsu, Hisakazu Kikuchi, Yoshikuni Onozato

    IEICE Trans. on Communications   E87-B ( 1 )   204 - 208   2004.1

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  • Spatial correlation of a circular array antenna and BER performance investigation Reviewed

    K Ishizawa, J Zhou, S Sasaki, S Muramatsu, H Kikuchi

    PROCEEDINGS OF THE 2004 IEEE ASIA-PACIFIC CONFERENCE ON CIRCUITS AND SYSTEMS, VOL 1 AND 2   1   385 - 388   2004

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    Multiple antenna arrays are promising architectures for overcoming the efects of multipath interference and increasing the spectrum efficiency. In order to be able to investigate these systems, in this article, we derive generalized spatial correlation equations of a circular antenna array for two types of angular energy distributions: a Gaussian angle distribution, and uniform angular distribution. The ganaralized spatial correlation equations and BER (:Bit Error Rate) performance is investigated. It has been reported that spatial correlation and BER performance using linear array antenna, but very few attempts have been made at circular array antenna [5][7]. It was found from the result that BER of receiving arrival wave with uniform distribution is better than that with gaussian distribution.

    DOI: 10.1109/APCCAS.2004.1412776

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  • Parameter embedding method of variable-coefficient invertible deinterlacing into motion-JPEG2000 through ROI Reviewed

    J Uchita, S Muramatsu, T Ishida, H Kikuchi, T Kuge

    2004 47TH MIDWEST SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOL II, CONFERENCE PROCEEDINGS   2   425 - 428   2004

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    In this work, a coefficient-parameter embedding method is proposed for invertible deinterlacing with variable coefficients in the application to Motion-JPEG2000 (MJP2). Invertible deinterlacing, which the authors have developed before, can be used as a preprocess of frame-based motion picture codec, such as MJP2, for interlaced videos. When the conventional field-interleaving is used instead, comb-tooth artifacts appear around edges of moving objects. On the other hand, the invertible deinterlacing technique allows us to suppress the comb-tooth artifacts and also to recover an original picture on demand. As previous works, the authors have developed a variable coefficient scheme with a motion detector, which realizes adaptability to local characteristics of given pictures. When applying this deinterlacing technique to video codec, however, it is required to send coefficient parameters to receivers for original picture recovery. This work proposes a parameter-embedding technique for MJP2 and constructs a standard stream which consists both of picture data and the parameters. We investigate to embed the parameters into the LH1 component of the wavelet domain through the ROI (region of interest) function of JPEG2000 without significant loss in the performance of comb-tooth suppression.

    DOI: 10.1109/MWSCAS.2004.1354184

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  • Perfect reconstruction deinterlacer banks for field scalable video compression Reviewed

    S Muramatsu, T Ishida, H Kikuchi

    ICIP: 2004 INTERNATIONAL CONFERENCE ON IMAGE PROCESSING, VOLS 1- 5   2279 - 2282   2004

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    Perfect reconstruction (PR) deinterlacer banks are proposed as new tools for spatio-temporal scalable video codec. The proposed systems separate a progressive video into two different progressive videos of a half frame rate and are novel from the viewpoint of filter-banks in that interlaced videos are given as intermediate data during, analysis and synthesis process. Unlike the conventional filter banks, Our systems are constructed in a way unique to multidimensional systems by using invertible deinterlacers which we have proposed before. This paper suggests two kinds of interlaced video formats: the vertical-temporal (VT) Quincunx and face-centered-orthorhombic (FCO) format. As a primal application, a spatio-temporal scalable video codec, or field scalable video codec (FSVC). system is experimented. This technique offers a functionality by which decoding a base layer by itself provides both of half-rate progressive and interlaced videos, and adding all enhancement layer improves the spatio-temporal resolution. Some experimental results of the filter banks combined with JPEG2000 show their potential for practical video codec applications.

    DOI: 10.1109/ICIP.2004.1421553

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  • Evaluation of selective Rake receiver in direct sequence ultra wideband communications in the presence of interference Reviewed

    MA Rahman, S Sasaki, J Zhou, S Muramatsu, H Kikuchi

    JOINT UWBST & IWUWBS 2004, CONFERENCE PROCEEDINGS   221 - 225   2004

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    Performance of selective Rake (SRake) receiver is evaluated for direct sequence ultra wideband (DS-UWB) communications considering an independent Rayleigh channel having exponentially decaying power delay profile (PDP). BEP performances are shown. The results obtained are compared with similar results in a channel having flat PDP. Assumption of a flat PDP (as was previously made in DS-SS) is found to predict the optimum spreading bandwidth to be lower and suboptimum operating performance beyond optimum spreading bandwidth to be severely worse than that is achievable in a real channel with an SRake receiver having fixed number of combined paths. Optimum spreading bandwidth for SRake in a channel having exponentially decaying PDP is shown to be much larger than the one in a channel having flat PDP. This is specifically a good-news for UWB communication. Effects of partial band interference have also been considered. Interference is found to be less effective in case of exponentially decaying PDP.

    DOI: 10.1109/UWBST.2004.1320968

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  • Performance evaluation of Rake reception of ultra wideband signals over multipath channels from energy capture perspective Reviewed

    MA Rahman, S Sasaki, J Zhou, S Muramatsu, H Kikuchi

    JOINT UWBST & IWUWBS 2004, CONFERENCE PROCEEDINGS   231 - 235   2004

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    In this paper, we derive the SEP for time-hopping M-ary PPM (TH-MPPM) UWB communication systems as a function of captured SNR per symbol and simplify the results for TH-BPSK. For TH-MPPM system, we incorporate the effect of modulation index (b) on SEP. The results obtained give us way to evaluate the performance of Rake reception of UWB signals in dense multipath channels from energy capture perspective. We present more general type of results that can be applied for verities of Rake implementations. We present simulation results using IEEE 802.15.3a UWB channel models for various pulse-widths. We evaluate the performances of optimum and ordinary all Rake (ARake) and selective Rake (SRake) receivers in different channel models (CM1 to CM3). We compare relative costs of simplifying various Rake complexities. Conditioned on some parameters, we present an optimum pulse-width for UWB communications while SRake is employed.

    DOI: 10.1109/UWBST.2004.1320970

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  • Performance Analysis of Packet Data Transmittion in Aeronautical Communication Systems by DS-CDMA Reviewed

    Kenta Ishizawa, Zhou Jie, Shigenobu Sasaki, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2003 6th International Symposium on Wireless Personal Multimedia Communications (WPMC)   3   460 - 464   2003.10

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  • Impact of Narrowband Interference and Timing Jitter in DS-UWB System Reviewed

    Shigenobu Sasaki, Takumi Kusama, Zhou Jie, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2003 6th International Symposium on Wireless Personal Multimedia Communications (WPMC)   2   274 - 277   2003.10

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  • Invertible deinterlacing with sampling-density preservation: Theory and design Reviewed

    S Muramatsu, T Ishida, H Kikuchi

    IEEE TRANSACTIONS ON SIGNAL PROCESSING   51 ( 9 )   2343 - 2356   2003.9

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    A novel class of deinterlacing for intra-frame/field-based motion-picture coding, such as Motion JPEG2000, as well as an inter-frame-based coding without the support of interlaced scanning video, such as MPEG-1, is developed. This technique has two features: sampling-density preservation and invertibility. These features mean that the amount of deinterlaced pictures is not increased, and the original pictures can be perfectly reconstructed. This deinterlacing technique is a kind of sampling-lattice alteration and is regarded as a generalization of conventional field interleaving and field separation. With the help of multidimensional (M-D) multirate theory, it is shown that the design problem of such a system, that is, invertible deinterlacer with sampling-density preservation, can be replaced to finding a 2 x 2 multivariable polynomial matrix with a monomial determinant. This problem resembles the design of two-channel M-D maximally decimated perfect-reconstruction finite-impulse-response (FIR) filterbanks. The inverse system, which is referred to as a reinterlacer, is given as FIR when the dual deinterlacing system is FIR. A practical design procedure is provided by suggesting three constraints considered to be preferable: normalization, regularity, and vertical symmetry. The significance of the procedure is verified by showing some design examples of deinterlacing and reinterlacing filters. Simulation results show that the developed method causes fewer comb-shaped artifacts than conventional field interleaving.

    DOI: 10.1109/TSP.2003.815368

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  • A lifting implementation of variable-coefficient invertible deinterlacer with embedded motion detector Reviewed

    T Ishida, T Soyama, S Muramatsu, H Kikuchi, T Kuge

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E86A ( 8 )   1942 - 1948   2003.8

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    In this paper, a lifting implementation of variable-coefficient invertible deinterlacer with embedded motion detector is proposed. As previous works, the authors have developed invertible deinterlacing that suppresses comb-tooth artifacts caused by field interleaving for interlaced scanning video, which affect the quality of intraframe-based codec such as Motion-JPEG2000. To improve the local adaptability for given pictures, its variable-coefficient processing with motion detection has also been proposed so that filters can be changed according to local properties of motion pictures, while maintaining the invertibility. In this paper, it is shown that the variable-coefficient invertible deinterlacing can be realized by a lifting-based simple hardware architecture, and motion detector can also be embedded. Both of the motion detection and deinterlacing filters are shared by a special choice of their coefficients, and by adaptive selection of deinterlacing filters. The significance of our proposed architecture is verified by showing synthesis results from the VHDL models. The proposed implementation with embedded motion detector achieves about 28% reduction of the gate count compared with the corresponding separate implementation.

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  • Parameter Decimation for Invertible Deinterlacing with Variable Coefficients Reviewed

    Jun Uchita, Takuma Ishida, Shogo Muramatsu, Hisakazu Kikuchi, Tetsuro Kuge

    Proc. of 2003 18th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   925 - 928   2003.7

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  • Spatial correlation functions for a circular antenna array and their applications in wireless communication systems Reviewed

    J Zhou, S Sasaki, S Muramatsu, H Kikuchi, Y Onozato

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E86A ( 7 )   1716 - 1723   2003.7

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    In this paper, we derive spatial correlation functions of linear and circular antenna arrays for three types of angular energy distributions: a Gaussian angle distribution, the angular energy distribution arising from a Gaussian spatial distribution, and uniform angular distribution. The spatial correlation functions are investigated carefully. The spatial correlation is a function of antenna spacing, array geometry and the angular energy distribution. In order to emphasize the research and their applications in diversity reception, as an example, performance of the antenna arrays with MRC in correlated Nakagami fading channels is investigated, in which analytical formulas of average BER for the spatial correlation are obtained.

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  • Extra encoding of fine grayscale data into 8-bit sRGB color space Reviewed

    H Kikuchi, H Sato, S Hasebe, N Mizutani, S Muramatsu, S Sasaki, J Zhou, S Sekine, Y Abe, Tofukuji, I, M Nakashizuka

    OPTICAL ENGINEERING   42 ( 7 )   1940 - 1948   2003.7

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    As an extra option, fine grayscale data that exceed eight bits per pixel are encoded into pseudogray colors in 8-bit sRGB color space to be displayed on an 8-bit sRGB CRT monitor. The characteristics of the pseudogray are investigated in terms of the CIELAB color difference and a*b* coordinates. (C) 2003 Society of Photo-Optical Instrumentation Engineers.

    DOI: 10.1117/1.1578492]

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  • Online SNR and Fading Parameter Estimation for Parallel Combinatorial SS Systems in Nakagami Fading Channels Reviewed

    Shigenobu Sasaki, Kazuyuki Uenaga, Ken-ichi Takizawa, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2003 18th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   394 - 397   2003.7

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  • Performance analysis of a DS-CDMA cellular system with cell splitting into macrocell and microcell architecture Reviewed

    J Zhou, S Sasaki, S Muramatsu, H Kikuchi, Y Onozato

    IEICE TRANSACTIONS ON COMMUNICATIONS   E86B ( 6 )   1967 - 1977   2003.6

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    The demand for wireless mobile communications has grown at a very high rate, recently. In order to solve the non-uniform traffic rates, the use of cell splits is unavoidable for balancing the traffic rate and maximizing total system capacity. For cell planning, a DS-CDMA cellular system can be comprise of different cell sizes because of different demands and population density of the service area. In this paper, we develop a general model to study the forward link capacity and outage probability of a DS-CDMA cellular system with mixed cell sizes. The analysis of outage probability is carried out using the log-normal approximation. When a macrocell is split into the three microcells, as an example, we calculate the multi-cross interferences between macrocells and microcells, and the forward link capacities for the microcells and the neighboring macrocells. The maximum allowable capacity plane for macrocell and microcell is also investigated. The numerical results and discussions with previous published results of reverse link are summarized.

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  • M-ary TH/CSK Modulation for Ultra-wideband Communications Reviewed

    Shigenobu Sasaki, Tomohiko Suzuki, Zhou Jie, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2003 International workshop on ultra wideband systems   2003.6

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  • Quality-Oriented Image Coding Using an Objective Measure of PSNR Reviewed

    Naoki Mizutani, Hiroto Sato, Shigenobu Sasaki, Shogo Muramatsu, Zhou Jie, Hisakazu Kikuchi

    Journal of Signal Processing   7 ( 3 )   229 - 237   2003.5

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  • Performance of Online SNR Estimation for Multicode DS/SS Systems in Multipath Fading Channels Reviewed

    Shigenobu Sasaki, Ken-ichi Takizawa, Kazuyuki Uenaga, Zhou Jie, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2003 World Wireless Congress   2003.5

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  • Lifting architecture of invertible deinterlacing Reviewed

    T Soyama, T Ishida, S Muramatsu, H Kikuchi, T Kuge

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E86A ( 4 )   779 - 786   2003.4

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    Several lifting implementation techniques for invertible deniterlacing are proposed in this paper. Firstly, the invertible deinterlacing is reviewed, and an efficient implementation is presented. Next, two deinterlacer-embedded lifting architectures of discrete wavelet transforms (DWT) is proposed. Performances are compared among several architectures of deinterlacing with DWT. The performance evaluation includes dual-multiplier and single-multiplier architectures. The number of equivalent gates shows that the deinterlacing-embedded architectures require less resources than the separate implementaion. Our experimental evaluation of the dual-multiplier architecture results in 0.8% increase in the gate count, whereas the separate implementation of deinterlacing and DWT requires 6.1% increase from the normal DWT architecture. For the proposed single-multiplier architecture, the gate count is shown to result in 4.5% increase, while the separate counterpart yields 10.7% increase.

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  • Invertible deinterlacing with variable coefficients and its lifting implementation Reviewed

    T Ishida, S Muramatsu, H Kikuchi, T Kuge

    2003 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH, AND SIGNAL PROCESSING, VOL III, PROCEEDINGS   105 - 108   2003

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    Invertible deinterlacing with variable coefficients is proposed to suppress comb-tooth artifacts caused by field interleaving of interlaced scanning video. A vertical highpass filter is applied to detect moving artifacts around boundaries of moving objects. The coefficients of a deinterlacing filter is varied depending on the motion intensity so that the deinterlacing filter may be matched to the local characteristics of moving pictures. Note that the deinterlacing filter is motion-adaptive and is time/translation-varying, while the deinterlacing is still kept to be invertible. The deinterlacing filter performance and its contribution to intraframe-based video coding are evaluated. In addition, since the processing of motion detection and a part of deinterlacing filtering can be shared, their efficient implementation is derived in the form of lifting popular in wavelets.

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  • Performance analysis of diversity reception schemes with STD in correlated Rayleigh fading channels Reviewed

    J Zhou, H Kikuchi, S Sasaki, S Muramatsu, Y Onozato

    2003 INTERNATIONAL CONFERENCE ON COMMUNICATION TECHNOLOGY, VOL 1 AND 2, PROCEEDINGS   2   870 - 873   2003

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    Diversity reception, a key technique derived against multi-path mitigation in wireless communication system, is examined and discussed. Especially, we present an approach to investigate perfect/imperfect channel detection when a simple transmit diversity scheme (STD)[9] are used in the wireless systems, which provide remarkable schemes for diversity transmission over Rayleigh-fading channels using multiple antennas. In order to effectively make use of the transmit diversity techniques, the same approach is extended to process the situation of two transmit antennas and N receive antennas in STD scheme (2 x N STD), in which the effects of perfect/imperfect channel detection and the diversity reception with independent and correlated Rayleigh-fading signals are evaluated and compared.

    DOI: 10.1109/ICCT.2003.1209670

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  • Invertible deinterlacing with variable coefficients and its lifting implementation Reviewed

    T Ishida, S Muramatsu, H Kikuchi, T Kuge

    2003 INTERNATIONAL CONFERENCE ON MULTIMEDIA AND EXPO, VOL III, PROCEEDINGS   177 - 180   2003

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    Invertible deinterlacing with variable coefficients is proposed to suppress comb-tooth artifacts caused by field interleaving of interlaced scanning video. A vertical highpass filter is applied to detect moving artifacts around boundaries of moving objects. The coefficients of a deinterlacing filter is varied depending on the motion intensity so that the deinterlacing filter may be matched to the local characteristics of moving pictures. Note that the deinterlacing filter is motion-adaptive and is time/translation-varying, while the deinterlacing is still kept to be invertible. The deinterlacing filter performance and its contribution to intraframe-based video coding are evaluated. In addition, since the processing of motion detection and a part of deinterlacing filtering can be shared, their efficient implementation is derived in the form of lifting popular in wavelets.

    DOI: 10.1109/ICME.2003.1221277

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  • Two-step algorithm for detecting video shot boundaries in a wavelet transform domain Reviewed

    S Hasebe, S Muramatsu, S Sasaki, J Zhou, H Kikuchi

    ISPA 2003: PROCEEDINGS OF THE 3RD INTERNATIONAL SYMPOSIUM ON IMAGE AND SIGNAL PROCESSING AND ANALYSIS, PTS 1 AND 2   1   245 - 250   2003

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    This paper presents a two-step algorithm that automatically detects shot boundaries of a video in a wavelet transform domain. It at first finds isolated intervals in a given video sequence, and then detects a shot boundary within those intervals. Its effectiveness for several different kinds of videos is evaluated in terms of recalls and precisions.

    DOI: 10.1109/ISPA.2003.1296902

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  • DWT gain compensation of motion-JPEG2000 for invertible deinterlacer Reviewed

    T Ishida, S Muramatsu, Z Jie, S Sasaki, H Kikuchi

    2003 INTERNATIONAL CONFERENCE ON IMAGE PROCESSING, VOL 2, PROCEEDINGS   223 - 226   2003

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    In this work, discrete-wavelet-transform (DWT) gain compensation of Motion-JPEG2000 (MJP2) for invertible deinterlacer is proposed. As previous works, we have developed invertible deinterlacer that suppresses comb-tooth artifacts caused by field interleaving for interlaced scanning video, which affect the quality of scalable intraframe-based codec such as MJP2. Our technique has two features that the sampling density is preserved and the image quality can be recovered by the inverse process on demand. When no codec is applied in between the deinterlacer and inverse process, the original video is perfectly reconstructed. Otherwise, it is approximately recovered. The purpose of this work is to improve the quality of recovered images when MJP2 codec is inserted. It is shown that our invertible deinterlacer can be embedded into the DWT. As a result, frequency weighting for rate-distortion control can be moderately compensated. Simulation results show that the quality recovery is improved more than 1.5 dB in PSNR by applying the proposed compensation compared with the original weighting at 2.0bpp of decoding rate for 8-bit grayscale pictures.

    DOI: 10.1109/ICIP.2003.1246657

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  • Spatial correlation for a circular antenna array and its applications in wireless communications Reviewed

    J Zhou, S Sasaki, S Muramatsu, H Kikuchi, Y Onozato

    GLOBECOM'03: IEEE GLOBAL TELECOMMUNICATIONS CONFERENCE, VOLS 1-7   1108 - 1113   2003

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    In this paper, we derive spatial correlation functions of linear and circular antenna arrays for three types of angular energy distributions: a Gaussian angle distribution, the angular energy distribution arising from a Gaussian spatial distribution, and uniform angular distribution. The spatial correlation functions are investigated carefully. The spatial correlation is a function of antenna spacing, array geometry and the angular energy distribution. In order to emphasize the research and their applications in diversity reception, as an example, performance of the antenna arrays with MRC in correlated Nakagami fading channels is investigated, in which analytical formulas of average BER for the spatial correlation are obtained.

    DOI: 10.1109/GLOCOM.2003.1258410

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  • Online SNR estimation for parallel combinatorial SS systems in Nakagami fading channels Reviewed

    K Takizawa, S Sasaki, J Zhou, S Muramatsu, H Kikuchi

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E85A ( 12 )   2847 - 2858   2002.12

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    In this paper, an online SNR estimator is proposed for parallel combinatorial SS (PC/SS) systems in Nakagami fading channels. The PC/SS systems are called as partial-code-parallel multicode DS/SS systems, which have the higher-speed data transmission capability comparing with conventional multicode DS/SS systems referred to as all-code-parallel systems. We propose an SNR estimator based on a statistical ratio of correlator outputs at the receiver. The SNR at the correlator output is estimated through a simple polynomial from the statistical ratio. We investigate the SNR estimation accuracy in Nakagami fading channels through computer simulations. In addition, we apply it to the convolutional coded PC/SS systems with iterative demodulation and decoding to evaluate the estimation performance from the viewpoint of error rate. Numerical results show that the PC/SS systems with the proposed SNR estimator have superior estimation performance to conventional DS/SS systems. It is also shown that the bit error rate performance using our SNR estimation method is close to the performance with perfect knowledge of channel state information in Nakagami fading channels and correlated Rayleigh fading channels.

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  • Performance investigation of two transmit diversity schemes with perfect/imperfect channel evaluation in wireless communications Reviewed

    J Zhou, H Kikuchi, S Sasaki, S Muramatsu, Y Onozato

    IEICE TRANSACTIONS ON COMMUNICATIONS   E85B ( 10 )   1957 - 1965   2002.10

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    Transmit diversity, a key technique derived against multi-path mitigation in wireless communication system, is examined and discussed. Especially, we present an approach to investigate perfect/imperfect channel detection when the maximal ratio receiver combined scheme (MRRC) and a simple transmit diversity scheme (STD) are used in the wireless systems, which provide remarkable schemes for diversity transmission over Rayleigh-fading channels using multiple antennas. In order to effectively make use of the transmit diversity techniques, the same approach is extended to process the situation of one transmit antennas and N receive antennas in MRRC scheme (1 x N MRRC) and two transmit antennas and N receive antennas in STD scheme (2 x N STD). The effects of perfect/imperfect channel detection and the diversity reception with independent and correlated Rayleigh-fading signals are evaluated and compared carefully.

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  • Performance Evaluation of Iterative Demodulation and Decoding for Coded Parallel Combianatorial SS Systems through a Uniform Interleaver Reviewed

    Kenichi Takizawa, Shigenobu Sasaki, Jie Zhou, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2002 IEEE International Symposium on Spread Spectrum Techniques and Applications   736 - 740   2002.9

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  • Reversible conversion between interlaced and progressive scan formats and its efficient implementation. Reviewed

    Hisakazu Kikuchi, Shogo Muramatsu, Takuma Ishida, Tetsuro Kuge

    Proc. of 2002 11th European Signal Processing Conference (EUSIPCO)   1 - 4   2002.9

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    Other Link: http://dblp.uni-trier.de/db/conf/eusipco/eusipco2002.html#conf/eusipco/KikuchiMIK02

  • Online SNR Estimation for Turbo Coded Multicode DS/SS Systems Reviewed

    Ken-ichi Takizawa, Shigenobu Sasaki, Zhou Jie, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2002 17th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   2   1316 - 1319   2002.7

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  • Forward link performance of TDMA/W-CDMA spectrum overlaid system with interference cancellation for future wireless communications Reviewed

    J Zhou, H Kikuchi, S Sasaki, S Muramatsu, Y Onozato

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E85A ( 7 )   1536 - 1545   2002.7

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    In this paper, the co-existence of TDMA and W-CDMA spectrum sharing system (TDMA/W-CDMA overlaid system) with cellular architecture is discussed. In this system, both systems share the same frequency band to improve the spectrum efficiency. Overall rate, bit error ratio (BER) and spectrum efficiency of the system are calculated for the forward link (down-link) in the presence of AWGN channel. Taking into account the path loss and shadow fading loss in this system with cellular architecture, W-CDMA applying interference cancellation (IC) shows a substantial difference in spectrum efficiency, the overlaid system can provide a greater overall rate arid higher spectrum efficiency than a single multiple access-based system such as TDMA system or W-CDMA system. The interference cancellation can significantly improve BER of the spectrum overlaid system.

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  • Performance bounds in convolutional coded parallel combinatorial SS systems Reviewed

    K Takizawa, S Sasaki, S Muramatsu, J Zhou, H Kikuchi

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E85A ( 7 )   1696 - 1701   2002.7

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    Upper bounds on the bit error rate (BER) for maximum likelihood (ML) decoding are derived in convolutional coded parallel combinatorial spread spectrum (PC/SS) systems over additive white Gaussian noise (AWGN) channels. PC/SS systems can achieve higher data transmission than conventional multicode SS systems. To make the derivation tractable, we put a uniform interleaver between a convolutional encoder and a PC/SS transmitter. Since the PC/SS transmitter is employed as the "inner encoder," the bounds are obtained in a similar manner of the derivation in serially concatenated codes through a uniform interleaver. Two different error patterns in the PC/SS system are considered in the performance analysis. Numerical results show that the derived BER bounds are sufficiently accurate. It is found that the coded PC/SS systems outperform coded all-code-parallel DS/SS systems under the same data rate conditions if the number of pre-assigned PN codes increases.

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  • Mapping of Fine Grayscale Data into the sRGB Color Space Reviewed

    Hisakazu Kikuchi, Hiroto Sato, Satoshi Hasebe, Naoki Mizutani, Shogo Muramatsu, Shigenobu Sasaki, Zhou Jie, Seishi Sekine, Yoshito Abe, Makoto Nakashizuka

    Proc. of 2002 17th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   2   987 - 990   2002.7

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  • Lifting Implementation of Reversible Deinterlacer Reviewed

    Takuma Ishida, Tatsuumi Soyama, Shogo Muramatsu, Hisakazu Kikuchi, Tetsuro Kuge

    Proc. of 2002 17th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   1   90 - 93   2002.7

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  • Analysis of Forward Link Capacity of a CDMA Cellular System with Mixed Cell Sizes Reviewed

    Hao Zhao, Hisakazu Kikuchi, Zhou Jie, Shigenobu Sasaki, Shogo Muramatsu

    Proc. of 2002 International Conference on Telecommunications   1   2002.6

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  • Performance of CDMA cellular system with effects of soft handover under log-normal shadow channels Reviewed

    J Zhou, H Kikuchi, S Sasaki, S Muramatsu, Y Onozato

    2002 INTERNATIONAL CONFERENCE ON COMMUNICATIONS, CIRCUITS AND SYSTEMS AND WEST SINO EXPOSITION PROCEEDINGS, VOLS 1-4   1   332 - 336   2002

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    next generation wireless communication is based on a global system of fixed and wireless mobile services that are transportable across different network backbones,network service providers and network geographical boundaries. Although the power control is essential for Direct Sequence Code Division Multiple Access (DS-CDMA) cellular systems to overcome the near-far problem, one of the most important problems for the system is handover management and its effects on the system. This paper presents an approach to investigate the effects of soft handover[1][2] and perfect power control[3][4] on the forward link in a DS-CDMA cellular system. Especially, the relationships between the size of handover zone and the capacity gain are evaluated under the log-normal shadow channel. Then the optimization of maximum forward capacity is very necessary to be done with the maximum size of soft handover zone to the various system characteristics.

    DOI: 10.1109/ICCCAS.2002.1180632

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  • Convergence rate evaluation of a DS-CDMA cellular system with centralized power control by genetic algorithms Reviewed

    J Zhou, JN Chen, H Kikuchi, S Sasaki, S Muramatsu

    WCNC 2002: IEEE WIRELESS COMMUNICATIONS AND NETWORKING CONFERENCE RECORD, VOLS 1 & 2   177 - 182   2002

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    In this paper, we propose an approach to solve the power control issue in a DS-CDMA cellular system using genetic algorithms (GAs). The transmitter power control developed in this paper has been proven to be efficient to control co-channel interference, to increase bandwidth utilization and to balance the comprehensive services that are sharing among all the mobiles with attaining a common signal-to-interference ratio (SIR). In this paper, the optimal centralized power control (CPC) vector is characterized and its optimal solution for CPC is presented using GAs, in which first in-first out (FIFO) stacks and non-linear decreasing functions are derived in the investigation for enforcing the convergence rate. Emphasis is put on the balance of services and convergence rate by using GAs.

    DOI: 10.1109/WCNC.2002.993486

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  • A design method of invertible de-interlacer with sampling density preservation Reviewed

    S Muramatsu, T Ishida, H Kikuchi

    2002 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH, AND SIGNAL PROCESSING, VOLS I-IV, PROCEEDINGS   3277 - 3280   2002

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    A new class of de-interlacing is developed for intra-frame-based motion picture coding such as Motion-JPEG2000. The proposed technique has two features: the sampling density preservation and the invertibility. Thus, the amount of de-interlaced pictures is not increased and the original pictures can perfectly be reconstructed. This technique is regarded as a generalization of the conventional field interleaving. The significance is verified by showing some design examples and simulation results. The proposed technique is also shown to cause less comb-shape artifacts than the conventional one. The intra-field-based case is also discussed.

    DOI: 10.1109/ICASSP.2002.5745353

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  • Spectrum efficiency of a TDMA/W-CDMA frequency sharing system with notch filters and signal clippers Reviewed

    H Kikuchi, J Zhou, S Sasaki, S Muramatsu, Y Onazato

    2002 INTERNATIONAL CONFERENCE ON COMMUNICATIONS, CIRCUITS AND SYSTEMS AND WEST SINO EXPOSITION PROCEEDINGS, VOLS 1-4   1   192 - 196   2002

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    in this article, the co-existence of TDMA and W-CDMA spectrum sharing system (TDMA/W-CDMA overlaid system) with cellular architecture is discussed. In this system, both systems share the same frequency band to improve the spectrum efficiency. Overall rate and spectrum efficiency of the system are calculated for the forward link (down-link) in the presence of AWGN channel. Taking into account the path loss and shadow fading loss in this system with cellular architecture, W-CDMA applying interference cancellation (IC) shows a substantial difference in. spectrum efficiency, the overlaid system can provide a greater overall rate and higher spectrum efficiency than a single multiple access-based system such as TDMA system or W-CDMA system.

    DOI: 10.1109/ICCCAS.2002.1180601

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  • Online SNR estimation for parallel combinatorial SS systems in nakagami fading channels Reviewed

    K Takizawa, S Sasaki, H Zhou, S Muramatsu, H Kikuchi

    GLOBECOM'02: IEEE GLOBAL TELECOMMUNICATIONS CONFERENCE, VOLS 1-3, CONFERENCE RECORDS   E85-A ( 12 )   1239 - 1243   2002

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    In this paper, a simple and accurate on-line SNR estimator is proposed for parallel combinatorial SS (PC/SS) systems in Nakagami fading channels. The PC/SS systems are a kind of partial-code-parallel multicode DS/SS systems., Our proposed SNR estimator estimates the SNR at the correlator output by using a statistical ratio of the sum of correlator outputs for pre-assinged PN codes. We investigate the SNR estimation accuracy in Nakagami fading channels through computer simulations. Numerical results show that the the proposed SNR estimator brings superior estimation performance to that in conventional estimator that has proposed by Summers and Wilson [9]. In addition, we apply it to the convolutional coded PC/SS systems with iterative demodulation and decoding to evaluate the estimation performance from the viewpoint of error rate. By using our estimator, the bit error rate performance is close to the performance with perfect knowledge of the SNR information in Nakagami fading channels and correlated Rayleigh fading channels.

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  • Error rate performance bounds in block coded parallel combinatorial SS systems through a uniform interleaver Reviewed

    K Takizawa, S Sasaki, J Zhou, S Muramatsu, H Kikuchi

    2002 IEEE SEVENTH INTERNATIONAL SYMPOSIUM ON SPREAD SPECTRUM TECHNIQUES AND APPLICATIONS, VOLS 1-3, PROCEEDINGS   736 - 740   2002

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    Upper bounds on the codeword and bit error probabilities are obtained for maximum-likelihood (ML) decoding of block coded parallel combinatorial spread spectrum (PC/SS) systems in additive white Gaussian noise (AWGN) channels. To make the analysis tractable, we put a uniform inter-leaver between a block encoder and a PC/SS transmitter. An input-output distance enumerating function (IODEF) is introduced to calculate the number of codewords for an overall coded PC/SS system instead of the input-output weight enumerating function (IOWEF). The average bounds on the bit error rate (BER) of block coded PC/SS systems on AWGN channels are shown. It is demonstrated that the performance advantage between PC/SS systems is determined by the number of information bits per active transmitting PN code. A comparison between the coded PC/SS systems and coded conventional multicode DS/SS systems is also discussed.

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  • Online SNR estimation for parallel combinatorial SS systems in nakagami fading channels Reviewed

    K Takizawa, S Sasaki, H Zhou, S Muramatsu, H Kikuchi

    GLOBECOM'02: IEEE GLOBAL TELECOMMUNICATIONS CONFERENCE, VOLS 1-3, CONFERENCE RECORDS   1239 - 1243   2002

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    In this paper, a simple and accurate on-line SNR estimator is proposed for parallel combinatorial SS (PC/SS) systems in Nakagami fading channels. The PC/SS systems are a kind of partial-code-parallel multicode DS/SS systems., Our proposed SNR estimator estimates the SNR at the correlator output by using a statistical ratio of the sum of correlator outputs for pre-assinged PN codes. We investigate the SNR estimation accuracy in Nakagami fading channels through computer simulations. Numerical results show that the the proposed SNR estimator brings superior estimation performance to that in conventional estimator that has proposed by Summers and Wilson [9]. In addition, we apply it to the convolutional coded PC/SS systems with iterative demodulation and decoding to evaluate the estimation performance from the viewpoint of error rate. By using our estimator, the bit error rate performance is close to the performance with perfect knowledge of the SNR information in Nakagami fading channels and correlated Rayleigh fading channels.

    DOI: 10.1109/GLOCOM.2002.1188395

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  • Iterative demodulation and decoding for parallel combinatorial SS systems Reviewed

    KI Takizawa, S Sasaki, S Muramatsu, H Kikuchi

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E84A ( 12 )   2991 - 2999   2001.12

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    This paper proposes iterative demodulation/decoding for parallel combinatorial spread spectrum (PC/SS) systems. A PC/SS system conveys information data by a combination of pre-assigned orthogonal spreading sequences with polarity. In this paper, convolutional coding with a uniform random interleaver is implemented in channel coding, just like as a serial concatenated coding. A 'soft-in/soft-out' PC/SS demodulator based on a posteriori probability algorithm is proposed to perform the iterative demodulation and decoding. Simulation results demonstrate that the proposed iterative demodulation/decoding scheme bring significant improvement in bit error rate performance. This proposed decoding scheme achieves highspeed transmission by two approaches. One is a puncturing operation, and the other is to increase the number of transmitting sequences. In the latter approach, lower error rate performance is achieved comparing with that the punctured convolutional code is used to increase the information bit rate.

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  • Convergence Rate Comparison of a DS-CDMA System with Centralized Power Control by Genetic Algorithms Reviewed

    Zhou Jie, Yoshikuni Onozato, Hisakazu Kikuchi, Shigenobu Sasaki, Shogo Muramatsu

    Proc. of 2001 Investigation of a CDMA Cellular System with Various Traffic Distribution, Solved by Combination of Tilted Antenna Array and Power Control   119 - 124   2001.10

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  • Investigation of a CDMA Cellular System with Various Traffic Distribution, Solved by Combination of Tilted Antenna Array and Power Control Reviewed

    Zhou Jie, Hisakazu Kikuchi, Shigenobu Sasaki, Shogo Muramatsu, Yoshikuni Onozato

    Proc. of 2001 International Conference on ITS Telecommunication   113 - 118   2001.10

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  • Separate FEC coding for parallel combinatorial spread spectrum communication systems. Reviewed

    Shigenobu Sasaki, Ken-ichi Takizawa, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2001 12th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)   F11 - F15   2001.9

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    DOI: 10.1109/PIMRC.2001.965285

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  • Memory access estimation of filter bank implementation on different DSP architectures Reviewed

    N Mizutani, S Muramatsu, H Kikuchi

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E84A ( 8 )   1951 - 1959   2001.8

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    A unified polyphase representation of analysis and synthesis filter banks is introduced in this paper, and then the efficient implementation on digital signal processors (DSP) is investigated. Especially, the number of memory accesses, power consumption, processing accuracy and the required instruction cycles are discussed. Firstly, a unified representation is given, and then two types of procedures, SIMO system-based and MISO system-based procedures, are shown, where SIMO and MISO are abbreviations for single-input/multiple-output and multiple-input/single-output, respectively. These procedures are compared to each other. It is shown that the number of data load in SIMO system-based procedure is a half of that in MISO system-based procedure for two-channel filter banks. The implementation of W-channel filter banks is also discussed.

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  • Video Querying Based on Three-Dimensional Wavelet Transforms Reviewed

    Satoshi Hasebe, Shogo Muramatsu, Shigenobu Sasaki, Hisakazu Kikuchi

    Proc. of 2001 16th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   2   1196 - 1199   2001.7

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  • Memory Access Estimation in Filter Bank Implementations Reviewed

    Naoki Mizutani, Takuma Ishida, Shogo Muramatsu, Shigenobu Sasaki, Hisakazu Kikuchi

    Proc. of 2001 16th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   2   696 - 699   2001.7

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  • Convolutional Coded Parallel Combinatorial Spread Spectrum Systems with Iterative Demodulation and Decoding Reviewed

    Ken-ichi Takizawa, Shigenobu Sasaki, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2001 16th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   2   740 - 743   2001.7

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  • On FEC Coding for Parallel Combinatorial Cpread Spectrum Systems Reviewed

    Shigenobu Sasaki, Shuho Meguro, Ken-ichi Takizawa, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2001 4th International Symposium on Multidimensional Mobile Communications   66 - 73   2001.6

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  • Iterative demodulation and decoding for parallel combinatorial SS systems Reviewed

    KI Takizawa, S Sasaki, Z Jie, S Muramatsu, H Kikuchi

    GLOBECOM &apos;01: IEEE GLOBAL TELECOMMUNICATIONS CONFERENCE, VOLS 1-6   2   811 - 815   2001

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    This paper proposes iterative demodulation/decoding for parallel combinatorial spread spectrum (PC/SS) systems. The PC/SS systems convey the information data by a combination of pre-assigned spreading sequences with the polarity. In this paper, convolutional coding with random interleaver is implemented as channel coding, just like as a serial concatenated concatenated coding. A &apos;soft-in/soft-out&apos; PC/SS demodulator based on a posteriori probability algorithm is proposed to perform the iterative demodulation and decoding. Simulation results demonstrate that the proposed iterative demodulation and decoding bring significant improvement in the bit error rate performance.

    DOI: 10.1109/GLOCOM.2001.965531

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  • Forward link power control strategy and its optimum issue on CDMA cellular network Reviewed

    J Zhou, Y Onozato, S Sasaki, S Muramatsu, H Kikuchi

    NINTH IEEE INTERNATIONAL CONFERENCE ON NETWORKS, PROCEEDINGS   498 - 503   2001

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    In this paper, we proposed a theoretical method in order to estimate the forward link outage probability and user capacity of a cellular system which are based on IS-95 CDMA standard, especially impact of power control strategy and voice activity monitoring on the system under long-term fading. According to the numerical results obtained in this paper, the power control strategy leads to approximately threefold the user capacity contrast to the situation without power control strategy. The power control strategy not only improves the desired signal to interference ratio in the reference user's receiver, but also offers uniform service to the user wherever it is located in the cell.

    DOI: 10.1109/ICON.2001.962392

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  • A Motion Estimation with Two Images of Less Gray Level? Reviewed

    Masayuki Kurosaki, Shogo Muramatsu, Hitoshi Kiya

    IEICE Trans. on Fundamentals   J83-A ( 12 )   1434 - 1440   2000.12

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    低階調画像を用いて動きベクトルを推定する場合,動きベクトルの推定精度は,量子化の際のしきい値の値に依存する.本論文では,しきい値を計算するための演算量を低減する二つの方法を提案する.一つは2種類の低階調画像を用いる方法で,他の一つは,マクロブロックを分割し,より細かい単位でしきい値を計算する方法である.これらの二つの方法は組み合わせて使用することも可能である.シミュレーションにより,提案法は,動きベクトルの推定精度を保ち,しきい値決定に要する演算量を低減できることが確認できた.

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  • A Fast Motion Estimation in the Wavelet Transform Domain for Video Compression Reviewed

    Sanghyun Joo, Shogo Muramatsu, Hisakazu Kikuchi

    Proc. of 2000 IEEE International Symposium on Intelligent Signal Processing and Communication Systems (ISPACS)   1   68 - 71   2000.11

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  • Motion estimation with power scalability and its VHDL model Reviewed

    A Takagi, S Muramatsu, H Kiya

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E83A ( 8 )   1608 - 1613   2000.8

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    In MPEG standard, motion estimation (ME) is used to eliminate the temporal redundancy of video frames. This ME is the most time-consuming task in the encoding of video sequences and is also the one using the most power. Using low-bit images can save power of ME and a conventional architecture fixed to a certain bit width is used for low-bit motion estimator. It is known that there is a trade-off between power and image quality. ME may be used in various situations, and the relation between demands for power or image quality will depend on those circumstances. We therefore developed an architecture for a low-bit motion estimator with adjustable power consumption. In this architecture, we can select the bit width for the input image and adjust the amount of power for ME. To evaluate its effectiveness, we designed the motion estimator by VHDL and used the synthesis results to estimate the performance.

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  • Error Resilience in Image Transmission Using LVQ and Turbo Coding Reviewed

    Junghyeun Hwang, Sanghyun Joo, Hisakazu Kikuchi, Shigenobu Sasaki, Shogo Muramatsu, Jueho Shin

    Proc. of 2000 15th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   1   478 - 481   2000.7

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  • A bit-operation algorithm of the median-cut quantization and its hardware architecture Reviewed

    S Muramatsu, H Kiya, A Yamada

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E83A ( 2 )   320 - 328   2000.2

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    In this paper, an algorithm of the median-cut quantization (MCQ) is proposed. MCQ is the technique that reduces multi-valued samples to binary-valued ones by adaptively taking thr median value as the threshold. In this work, the search process of the median value is derived from the quick-sort algorithm. The proposed algorithm searches the median value bit by bit, and samples are quantized during the search process. Firstly the bit-parallel procedure is shown, and then it is modified to the bit-parallel procedure. The extension to the multi-level quantization is also discussed. Since the proposed algorithm is based on bit operations, it is suitable for hardware implementation. Thus, its hardware architecture is also proposed. To verify the significance, for the application to the motion estimation, the performance is estimated from the synthesis result uf the VHDL model.

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  • Motion estimation with power scalability and its VHDL model Reviewed

    A Takagi, S Muramatsu, H Kiya

    2000 INTERNATIONAL CONFERENCE ON IMAGE PROCESSING, VOL III, PROCEEDINGS   3   118 - 121   2000

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    In MPEG standard, motion estimation (ME) is used to eliminate the temporal redundancy of video frames. This ME is the most time-consuming task in the encoding of video sequences and is also the one using the most power. Using low-bit images can save power of ME and a conventional architecture fixed to a certain bit width is used for low-bit motion estimator. It is known that there is a trade-off between power and image quality ME may be used in various situations, and the relation between demands for power or image quality will depend on those circumstances. We therefore developed an architecture for a low-bit motion estimator with adjustable power consumption. In this architecture, we can select the bit width for the input image and adjust the amount of power for ME. To evaluate its effectiveness, we designed the motion estimator by VHDL and used the synthesis results to estimate the performance.

    DOI: 10.1109/ICIP.2000.899309

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  • Two-channel QMF bank without checkerboard effect and its lattice structure Reviewed

    Y Harada, S Muramatsu, H Kiya

    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART III-FUNDAMENTAL ELECTRONIC SCIENCE   82 ( 11 )   74 - 85   1999.11

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    Filter banks are usually designed so that the perfect reconstruction condition is satisfied. This condition, however, is not always satisfied in actual applications. In such a case, the filter bank operates as a time-varying system, and checkerboard distortion is produced by the time-varying effect. This paper discusses the checkerboard effect in a two-channel filter bank, including the effect of finite word length implementation and the case in which the perfect reconstruction condition is not satisfied. The general condition for avoiding the checkerboard effect is formulated. A design procedure for a paraunitary QMF bank satisfying that condition, as well as an implementation by the lattice configuration, are shown. It is furthermore shown that the checkerboard effect can be minimized in a finite word length implementation by employing the proposed lattice configuration and adding a correction to the rotation angle. (C) 1999 Scripta Technica, Electron Comm Jpn Pt 3, 82(11): 74-85, 1999.

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  • A Unified Module Architecture for Forward and Inverse Discrete Wavelet Transforms Reviewed

    Shogo Muramatsu, Hitoshi Kiya, Akihiko Yamada

    Proc. of 2000 European Conference on Circuit Theory and Design (ECCTD)   1   583 - 586   1999.9

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  • Consideration on Low Power Motion Estimation with Less Gray Level Images Reviewed

    Ayuko Takagi, Hitoshi Kiya, Shogo Muramatsu, Akihiko Yamada

    Proc. of 1999 14th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   1   9 - 12   1999.7

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  • VLSI Architecture of Motion Estimator with 8×8 Block Mode for MPEG4 and Its VHDL Model Reviewed

    Kenji Sakamoto, Shogo Muramatsu, Hitoshi Kiya, Akihiko Yamada

    Proc. of 1999 14th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   1   340 - 343   1999.7

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  • inear-Phase Paraunitary Filter Banks for Image Processing Reviewed

    MURAMATSU Shogo

    Tokyo Metropolitan University   1 - 134   1998.11

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  • A design method of 2-D axial-symmetric paraunitary filter banks with a lattice structure. Reviewed

    Shogo Muramatsu, Akihiko Yamada, Hitoshi Kiya

    Proc. of 1998 9th European Signal Processing Conference (EUSIPCO)   1 - 4   1998.9

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  • Multidimensional multirate filter without checkerboard effects. Reviewed

    Yasuhiro Harada, Shogo Muramatsu, Hitoshi Kiya

    Proc. of 1998 9th European Signal Processing Conference (EUSIPCO)   1 - 4   1998.9

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  • The two-dimensional lapped Hadamard transform Reviewed

    S Muramatsu, A Yamada, H Kiya

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E81A ( 8 )   1542 - 1549   1998.8

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    In this paper, a two-dimensional (2-D) binary valued (BV) lapped transform (LT) is proposed. The proposed LT has basis images which take only BV elements and satisfies the axial-symmetric (AS) properly. In one dimension, there is no 2-point LT with the symmetric basis vectors, and the property is achieved only with the non-overlapping basis which the Hadamard transform (HT) has. Hence, in two dimension, there is no 2 x 2-point separable ASLT, and only 2-D I-IT can be the 2 x 2-point separable AS orthogonal transform. By taking nonseparable BV basis images, this paper shows that a 2 x 2-point ASLT can be obtained. Since the proposed LT is similar to HT, it is referred to as the lapped Hadamard transform (LHT). LHT of larger size is shown to be provided with a tree structure. In addition, LHT is shown to be efficiently implemented by a lattice structure.

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  • Multidimensional multirate filter and filter bank without checkerboard effect Reviewed

    Y Harada, S Muramatsu, H Kiya

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E81A ( 8 )   1607 - 1615   1998.8

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    The checkerboard effect is caused by the periodic time-variant property of multirate filters which consist of up-samplers and digital filters. Although the conditions for some one-dimensional (1D) multirate systems to avoid the checkerboard effect have been shown, the conditions for Multidimensional (MD) multirate systems have not been considered. In this paper, some theorems about the conditions for MD multirate filters without checkerboard effect are derived. In addition, we also consider MD multirate filter banks without checkerboard effect. Simulation examples show that the checkerboard effect can be avoided by using the proposed conditions.

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  • A design method of odd-channel linear-phase paraunitary filter banks with a lattice structure Reviewed

    S Muramatsu, H Kiya

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E81A ( 5 )   976 - 980   1998.5

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    In this letter, a design method of linear-phase paraunitary filter banks is proposed for an odd number of channels. In the proposed method, a non-linear unconstrained optimization process is assumed to be applied to a lattice structure which makes the starting guess of design parameters simple. In order to avoid insignificant local minimum solutions, a recursive initialization procedure is proposed. The significance of our proposed method is verified by some design examples.

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  • A Design Method of Odd-Channel Linear-Phase Paraunitary Filter Banks with a Lattice Structure Reviewed

    Shogo Muramatsu, Hitoshi Kiya

    IEICE Trans. on Fundamentals   E81-A ( 5 )   976 - 980   1998.5

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    In this letter, a design method of linear-phase paraunitary filter banks is proposed for an odd number of channels. In the proposed method, a non-linear unconstrained optimization process is assumed to be applied to a lattice structure which makes the starting guess of design parameters simple. In order to avoid insignificant local minimum solutions, a recursive initialization procedure is proposed. The significance of our proposed method is verified by some design examples.

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  • The Two-Dimensional Lapped Hadamard Transform Reviewed

    Shogo Muramatsu, Akihiko Yamada, Hitoshi Kiya

    Proc. of 1998 IEEE International Symposium on Circuits and Systems (ISCAS)   5   86 - 89   1998.5

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    DOI: 10.1109/ISCAS.1998.694414

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  • The two-dimensional lapped Hadamard transform Reviewed

    S Muramatsu, A Yamada, H Kiya

    ISCAS '98 - PROCEEDINGS OF THE 1998 INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS 1-6   E81-A ( 8 )   D86 - D89   1998

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    In this paper, a 2-D binary-valued (BV) lapped transform (LT) is proposed. The proposed LT has basis images which take only BV elements and satisfies the axial-symmetric (AS) property. In ID, there is no 2-point LT with the symmetric basis vectors. Hence, in 2D, there is no 2 x 2-point separable ASLT. By taking non-separable BV basis images, this paper shows that a 2 x 2-point ASLT can be obtained. For its similarity to the Hadamard transform (HT), this paper refer to it as the lapped Hadamard transform (LHT). The efficient implementation is also given.

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  • Two-Channel QMF Bank without Checkerboard Effect and Its Lattice Structure Reviewed

    HARADA Yasuhiro, MURAMATSU Shogo, KIYA Hitoshi

    The Transactions of the Institute of Electronics,Information and Communication Engineers. A   80 ( 11 )   1857 - 1867   1997.11

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    フィルタバンクは,多くの場合,完全再構成条件を満たすように設計されるが,実際の使用においては,必ずしもこの条件は満足されない.このとき,フィルタバンクは時変システムとして動作し,この時変性の影響によりチェス盤ひずみが発生する.本論文では,2分割フィルタバンクにおいて,有限語長実現の影響や完全再構成条件を満たさない場合も含めチェス盤ひずみの考察を行い,チェス盤ひずみを回避するための条件を一般的に定式化する.また,その条件を満足するパラユニタリQMFバンクの設計法およびそのラティス構成による実現法を示す.更に,有限語長で実現する際に,このラティス構成を用いることにより回転角に補正角を加えることでチェス盤ひずみを極力抑えることが可能であることを示す.

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  • An efficient structure of generalized lapped orthogonal transforms for finite-duration sequences and its application to M-band discrete-time wavelet transforms Reviewed

    S Muramatsu, H Kiya

    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART III-FUNDAMENTAL ELECTRONIC SCIENCE   80 ( 10 )   39 - 50   1997.10

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    This paper describes an efficient structure for generalized lapped orthogonal transforms (GenLOT) for finite-duration sequences, which we expect to be used for subband image coding. When linear convolution is carried out on the finite-duration sequences and filter, the number of points in the output signal increases. Therefore, the linear convolution is not desirable in subband image coding. In order to solve this problem, the convolution is carried out after the finite-duration sequences are symmetrically and periodically extended (symmetric extension method). This method is superior to circular. convolution because the former method causes less distortion at the signal boundaries. In the GenLOT structure proposed in this paper, the symmetric extension can be realized without redundant operations due to signal extension and, furthermore, with fast implementation. This structure is considered to be a generalization of the lapped orthogonal transform (LOT) for finite-duration sequences. In addition, its application to the M-band discrete-time wavelet transform (DTWT) will be described. Finally, it will be shown that an efficient structure for finite-duration sequences can be realized in the M-band DTWT. (C) 1997 Scripta Technica, Inc.

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  • FTT-based implementation of sampling rate conversion with a small number of delays Reviewed

    XX Zou, S Muramatsu, H Kiya

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E80A ( 8 )   1367 - 1375   1997.8

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    Block delay caused by using fast Fourier transform (FFT), and computational complexity in sampling rate conversion system are considered in this paper. The relationship between the number of block delays and the computational complexity is investigated. The proposed method can avoid the redundant operations of sampling rate conversion completely and moreover provide a good trade-off between the number of block delays and the computational complexity. As a result, it is shown that with the proposed method, the sampling rate conversion can be realized more efficiently under a small number of blocks delays.

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  • Block sampling rate conversion for delay reduction Reviewed

    XX Zou, S Muramatsu, H Kiya

    ISCAS '97 - PROCEEDINGS OF 1997 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS I - IV   4   2357 - 2360   1997

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    A new implementation method for sampling rate conversion (SRC) is discussed in this work. Since the proposed method performs sampling rate conversion in a block way via FFT and inverse FFT (IFFT), we call the sampling rate conversion in this case the block sampling rate conversion (BSRC). The proposed method can reduce the additional input-output delay resulted from the use of FFT and trade-off it against the computational complexity more easily, compared with other FFT-based approaches.

    DOI: 10.1109/ISCAS.1997.612796

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  • A design method of multidimensional linear-phase paraunitary filter banks with a lattice structure Reviewed

    S Muramatsu, A Yamada, H Kiya

    IEEE TENCON&apos;97 - IEEE REGIONAL 10 ANNUAL CONFERENCE, PROCEEDINGS, VOLS 1 AND 2   1   69 - 72   1997

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    A lattice structure of multidimensional (MD) linear-phase paraunitary filter banks (LPPUFBs) is proposed, which makes it possible to design such filter banks in a systematic manner. The proposed structure can produce MD-LPPUFBs whose filters all have the region of support N(M Xi), where M and Xi are the decimation and an integer diagonal matrices, respectively, and ni (N) is the set of integer vectors in the fundamental parrallelpiped of N. Since our proposed system structurally restricts both the paraunitary and linear-phase properties, an unconstrained optimization process can be used to design MD-LPPUFBs. Some design examples will show the significance.

    DOI: 10.1109/TENCON.1997.647260

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  • An Efficient Structure of GenLOT for Finite-Duration Sequences and Its Application to M-Band Discrete-Time Wavelet Transforms Reviewed

    Shogo Muramatsu, Hitoshi Kiya

    IEICE Trans. on Fundamentals   J79-A ( 12 )   1966 - 1976   1996.12

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    本論文では,サブバンド画像符号化において応用が期待されている一般化重複直交変換(GenLOT: Generalized Lapped Orthogonal Transforms)の有限長信号に対する効果的な構成を提案する.有限長信号とフィルタとの直線畳込みを行うと,出力信号の点数が増加する.この理由から,サブバンド画像符号化において直線畳込みを行うことは望ましくない.そこで,この問題の解決法として,有限長信号を対称かつ周期的に拡張し,畳込みを行う対称拡張法が提案されている.この方法は,信号境界部分でのひずみが少ない点で循環畳込みよりも優れている.今回提案するGenLOTの構成は,信号拡張による冗長な処理を伴わずに対称拡張法を実現するものであり,高速処理が可能な利点ももつ.また,重複直交変換(LOT: Lapped Orthogonal Transforms)の有限長信号に対する構成の一般化としてみなすことができる.本論文では,更に,提案する構成のM帯域の離散時間ウェーブレット(DTWT: Discrete-Time Wavelet Transforms)への拡張についても議論する.結果として,M帯域DTWTにおいても,有限長信号に対する効果的な構成が得られることを示す.

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  • A design method for oversampled paraunitary DFT filter banks using householder factorization. Reviewed

    Kuniyuki Kajita, Hiroyuki Kobayashi, Shogo Muramatsu, Akihiko Yamada, Hitoshi Kiya

    Proc. of 1996 8th European Signal Processing Conference (EUSIPCO)   1 - 4   1996.9

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  • A new design method of linear-phase paraunitary filter banks with an odd number of channels. Reviewed

    Shogo Muramatsu, Hitoshi Kiya

    Proc. of 1996 8th European Signal Processing Conference (EUSIPCO)   1 - 4   1996.9

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  • A new factorization technique for the generalized linear-phase LOT and its fast implementation Reviewed

    S Muramatsu, H Kiya

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E79A ( 8 )   1173 - 1179   1996.8

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    In this work, a new structure of M-channel linear-phase paraunitary filter banks is proposed, where nl is even. Our proposed structure can be regarded as a modification of the conventional generalized linear-phase lapped orthogonal transforms (GenLOT) based on the discrete cosine transform (DCT). The main purpose of this work is to overcome the limitation of the conventional DCT-based GenLOT, and improve the performance of the fast implementation. II is shown that our proposed fast GenLOT is superior to that of the conventional technique in terms of the coding gain. This work also provides a recursive initialization design procedure so as to avoid insignificant local-minimum solutions in the non-linear optimization processes. In order to verify the significance of our proposed method, several design examples are given. Furthermore, it is shown that the fast implementation can be used to construct ni-band linear-phase orthonormal wavelets with regularity.

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  • Design Methods for Oversampled DFT Filter Banks Reviewed

    Kuniyuki Kajita, Kobayashi Hiroyuki, Shogo Muramatsu, Akihiko Yamada, Hitoshi Kiya

    Proc. of 1996 11st International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)   1122 - 1125   1996.7

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  • The generalized overlap-add and overlap-save methods using discrete sine and cosine transforms for FIR filtering Reviewed

    XX Zou, S Muramatsu, H Kiya

    ICSP '96 - 1996 3RD INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING, PROCEEDINGS, VOLS I AND II   1   91 - 94   1996

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    In this work, we investigate the generalized overlap add and overlap-save methods (GenOLA and GenOLS) using discrete sine and cosine transforms (DST's & DCT's). Compared to the GenOLA and GenOLS using discrete Fourier Transform (DFT), the merit of the DST & DCT approach is that the filtering can be implemented by real-valued operations. It is shown that the computational complexity can be minimized when the transform size of DST or DCT is chosen optimally, and a good tradeoff between the computational complexity and system delay can be achieved.

    DOI: 10.1109/ICSIGP.1996.566980

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  • PARALLEL-PROCESSING TECHNIQUES FOR MULTIDIMENSIONAL SAMPLING LATTICE ALTERATION BASED ON OVERLAP-ADD AND OVERLAP-SAVE METHODS Reviewed

    S MURAMATSU, H KIYA

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E78A ( 8 )   934 - 943   1995.8

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    In this paper, we propose two parallel processing methods for multidimensional (MD) sampling lattice alteration. The use of our proposed methods enables us to alter the sampling lattice of a given MD signal sequence in parallel without any redundancy caused by up- and down-sampling, even if the alteration is rational and non-separable. Our proposed methods are provided by extending two conventional block processing techniques for FIR filtering: the overlap-add method and the overlap-save method. In these proposed methods, firstly a given signal sequence is segmented into some blocks, secondly sampling lattice alteration is implemented for each block data individually, and finally the results are fitted together to obtain the output sequence which is identical to the sequence obtained from the direct sampling lattice alteration. Besides, we provide their efficient implementation: the DFT-domain approach, and give some comments on the computational complexity in order to show the effectiveness of our proposed methods.

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  • Optimum Block size of Discrete Sine and cosine Transforms for Symmetric Convolution Reviewed

    Xiaoxia Zou, Shogo Muramatsu, Hitoshi Kiya

    Proc. of 1995 10th Joint Technical Conference on Circuits/Systems, Computers and Communications (JTC-CSCC)   1   101 - 104   1995.7

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  • AN EXTENDED OVERLAP-ADD METHOD AND OVERLAP-SAVE METHOD FOR SAMPLING RATE CONVERSION Reviewed

    S MURAMATSU, H KIYA

    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART III-FUNDAMENTAL ELECTRONIC SCIENCE   78 ( 3 )   62 - 73   1995.3

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    The overlap-add (OLA) and overlap-save (OLS) methods are well known as efficient schemes for higher-order filtering. In those methods, the linear convolution for the infinite-duration data is reduced to the circular convolution for the finite blocks, and the fast-Fourier transform (FFT) is applied to the execution of the circular convolution.
    This paper proposes new OLA and OLS methods, which can directly be applied without a redundancy to the rate conversion. First, the conventional theory is extended for the finite-duration data. Then, the result is generalized for the infinite-duration data. Two methods are proposed as the main result in this paper, which are the extended overlap-add and extended overlap-save methods. Finally, the proposed method is compared to the polyphase structure, which is well known as an effective realization method for the rate conversion.

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  • Multidimensional parallel processing methods for rational sampling lattice alteration Reviewed

    S MURAMATSU, H KIYA

    1995 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS 1-3   756 - 759   1995

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    DOI: 10.1109/ISCAS.1995.521627

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  • RESOLUTION CONVERSION METHOD WITH ARBITRARY RATIONAL VALUES FOR TRANSFORM-CODED IMAGES Reviewed

    S MURAMATSU, H KIYA

    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART III-FUNDAMENTAL ELECTRONIC SCIENCE   77 ( 10 )   37 - 48   1994.10

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    The decimation and interpolation (contraction and expansion) processings of the image based on the orthogonal transform are simple and useful in the communication and storage of the digital image data. Consequently, their application to the resolution conversion of the image is expected. The conversion factor in this type of resolution conversion can be set as an arbitrary rational number if the size of the matrices in the forward and backward transforms can de set arbitrarily.
    On the other hand, the size of the transform matrix in the encoding is specified by the international standard and other specifications and it is not possible to set the conversion factor arbitrarily on the decoding side. When the transform matrix has the size of N, for example, the conversion factor is restricted to be the integer multiple of 1/N.
    From such a viewpoint, this paper proposes a method that can realize a resolution conversion with an arbitrary conversion factor even if the transform matrix size in the encoding is already specified. The basic principle of the proposed method is to combine the conventional method and the decimation processing and can be characterized as a more general method than the conventional method.
    By a discussion based on the filter bank and multirate system, the effective configuration for the proposed method is shown. It is shown also as a result that the conversion with an arbitrary rational factor can be executed with nearly the same computational complexity as in the conventional method. A simulation is executed using DCT and LOT and the effectiveness of the proposed method is demonstrated while indicating the problems in DCT.

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  • An Extended Overlap-Add Method and Save Method for Sampling Rate Conversion (in Japanese) Reviewed

    Shogo Muramatsu, Hitoshi Kiya

    電子情報通信学会論文誌 A   J77-A ( 8 )   1046 - 1055   1994.8

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  • Resolution Conversion Method with Arbitrary Rational Values for Transform-Coded Images Reviewed

    MURAMATSU Shogo, KIYA Hitoshi

    The Transactions of the Institute of Electronics,Information and Communication Engineers. A   77 ( 3 )   369 - 378   1994.3

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    ディジタル画像データの通信や蓄積の分野において,直交変換に基づく拡大・縮小処理が,その容易さと有効性から,画像の解像度変換への応用に期待されている.この解像度変換法は,もし順変換と逆変換の行列サイズを任意に選択可能ならば,その変換倍率を任意の有理数に選ぶことができる.しかしながら,国際規格等によって,符号化の際の変換サイズは決まっており,復号側において,変換倍率を任意に選ぶことが不可能となる.例えば変換サイズがNの場合,変換倍率は1/Nの整数倍に制限されてしまう.そこで本論文では,符号化の際の変換サイズが固定の場合においても,任意の有理数倍率の解像度変換を可能にする方法について提案する.提案法の基本原理は,従来法と間引き処理を組み合わせた構成であり,より一般的な形として位置づけることができる.また,フィルタバンクとマルチレートシステムに基づく考察により,提案法の効果的な構成を示す.この結果,任意の有理数倍率の変換においても,従来法と同程度の演算量で実行可能となる.また,DCTとLOTを使用したシミュレーションを行い,提案法の有効性を示し,DCTのもつ問題点を指摘する.

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  • AN EXTENDED OVERLAP-ADD METHOD AND OVERLAP-SAVE METHOD FOR SAMPLING RATE CONVERSION Reviewed

    S MURAMATSU, H KIYA

    1994 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOL 2   77 ( 8 )   B313 - B316   1994

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:I E E E  

    高次のFIRフィルタによる直線畳込みを効果的に実行する一手法として,重複加算法(OLA)や重複保持法(OLS)がある.これらの方法は,無限長データに対する直線畳込みを,有限なブロックごとの循環畳込みに帰着させ,その循環畳込みの実行に高速フーリエ変換(FFT)を利用できる.本論文ではレート変換においても冗長性なしに直接適用可能な新しいOLAとOLSを提案する.論文中では,まず有限長データのもとで,従来の理論を拡張する.次に,無限長データに対してそれを一般化し,本論文の目的である拡張重複加算法と拡張重複保持法の二つの方法を提案する.最後に,レート変換の効果的な実現技術として知られるポリフェーズ構成と本方法を比較し,提案法の有効性を示す.

    DOI: 10.1109/ISCAS.1994.408967

    Web of Science

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  • SCALE FACTOR OF RESOLUTION CONVERSION BASED ON ORTHOGONAL-TRANSFORMS Reviewed

    S MURAMATSU, H KIYA, M SAGAWA

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E76A ( 7 )   1150 - 1153   1993.7

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    It is known that the resolution conversion based on orthogonal transform has a problem that is difference of luminance between the converted image and the original. In this paper, the scale factor of the system employing various orthogonal transforms is generally formulated by considering the DC gain, and the condition of alias free for DC component is indicated. If the condition is satisfied, then the scale factor is determined by only the basis functions.

    Web of Science

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  • Scale Factor of Resolution Conversion in Transform/Subband Domain Reviewed

    Shogo MURAMATSU, Hitoshi KIYA

    Proc. of 1993 Joint Technical Conference on Circuits/Systems, Computers and Communications (JTC-CSCC)   179 - 184   1993.7

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Books

  • カメラ×センサ!ラズベリー・パイ製作全集[基盤3枚入り] : すぐに作れるAI/ロボット/スパコンからソフトウェア・ラジオ/ハイレゾ・オーディオまで

    トランジスタ技術編集部

    CQ出版  2019  ( ISBN:9784789847025

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    CiNii Books

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  • MATLABによる画像&映像信号処理―ツールを使った実践的アプリケーション開発 (ディジタル信号処理シリーズ)

    村松 正吾( Role: Sole author)

    CQ出版  2007.5  ( ISBN:4789830942

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    Total pages:295  

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  • マルチメディア技術の基礎 DCT(離散コサイン変換)入門―JPEG/MPEGからウェーブレット、重複直交変換(LOT)まで (エッセンス・シリーズ)

    貴家 仁志, 村松 正吾( Role: Joint author)

    CQ出版  1997.8  ( ISBN:4789836797

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    Total pages:234  

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MISC

  • Report on the Special Event "System and Signal Processing Subsociety Project: Panel Discussion" (June 2020, at the Joint Meeting of 4 Research Groups)

    14 ( 4 )   347 - 348   2021.4

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    Authorship:Lead author, Corresponding author   Language:Japanese   Publishing type:Meeting report   Publisher:Institute of Electronics, Information and Communications Engineers (IEICE)  

    DOI: 10.1587/essfr.14.4_347

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  • ICASSP 2019 Report

    村松 正吾

    映像情報メディア学会誌 = The journal of the Institute of Image Information and Television Engineers   73 ( 5 )   909 - 914   2019.9

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  • 河川防災とデータ駆動科学の融合

    村松 正吾

    新潟大学第5回U-goサロン   2018.12

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  • Let's go to IEICE Workshops!:Signal Processing (SIP)

    MURAMATSU Shogo

    IEICE ESS FUNDAMENTALS REVIEW   12 ( 1 )   71b - 72   2018

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  • International Conference Report:The 32nd International Technical Conference on Circuits/Systems, Computers and Communications

    MURAMATSU Shogo

    Fundamentals Review   11 ( 2 )   121 - 122   2017

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  • 20cm以下の床下をらくらく点検! Piカメラ偵察ローバ

    MURAMATSU Shogo

    トランジスタ技術   53 ( 12 )   49 - 66   2016.12

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  • ICASSP 2014 Report

    Muramatsu Shogo

    The journal of the Institute of Image Information and Television Engineers   68 ( 9 )   739 - 744   2014.9

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    今年5月,イタリアのフィレンツェにて開催された国際会議ICASSP2014について報告する.同会議は,IEEE Signal Processing Societyがフラグシップ会議として毎年主催する信号処理に関する世界最大級の国際会議である.今年で第39回目を向かえ,3,500件を超える投稿数を記録した.このうち,1,755件の論文が採択され発表の場を与えられた.

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  • Niigata Report

    MURAMATSU Shogo, MAEDA Yoshinobu, NAKANO Keisuke

    Fundamentals Review   7 ( 3 )   290 - 291   2014

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  • Video processing system development via MATLAB

    Shogo Muramatsu

    Kyokai Joho Imeji Zasshi/Journal of the Institute of Image Information and Television Engineers   65 ( 11 )   1571 - 1574   2011

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  • (24) Unit Testing on MATLAB

    Shogo Muramatsu

    Kyokai Joho Imeji Zasshi/Journal of the Institute of Image Information and Television Engineers   63 ( 6 )   777 - 779   2009.9

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  • C言語による情報理論入門, 久保田一, 大石邦夫, 福本昌弘(共著), "C言語による情報理論入門", コロナ社, 2007-06, A5判, 定価(2,500円+税)

    村松 正吾

    電子情報通信学会誌   91 ( 1 )   2008.1

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  • MATLABでオブジェクト指向プログラミング (特集 標準の記法を使って仕様をもむ,バグを出す,コードを作る 組み込みシステム開発に"損して得とる"モデリング)

    村松 正吾

    インタ-フェ-ス   33 ( 10 )   66 - 70   2007.10

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  • コンピュータ・シミュレーションやデータ解析の結果をビジュアルに概観 ここから始めるモデリング《MATLAB編》 (特集 標準の記法を使って仕様をもむ,バグを出す,コードを作る 組み込みシステム開発に"損して得とる"モデリング)

    村松 正吾

    インタ-フェ-ス   33 ( 10 )   52 - 65   2007.10

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  • IWAIT 2006

    MURAMATSU Shogo

    ITEJ   60 ( 4 )   2006.4

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Presentations

  • Sparsity-Aware High-Dimensional Data Restoration with Convolutional Dictionary Learning Invited

    Shogo Muramatsu

    IEEE/IEIE ICCE-Asia 2020  2020.11 

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  • 畳み込みネットワークによる高次元信号復元と異分野融合への展開 ~ スパースモデリングと畳み込み辞書学習 ~ Invited

    村松正吾

    映像情報メディア学会メディア工学研究会  2020.5 

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    Language:Japanese   Presentation type:Oral presentation (invited, special)  

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  • Image Restoration with Convolutional Dictionary Learning Invited

    Shogo MURAMATSU

    2019.12 

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  • Sparsity-Aware Image and Volumetric Data Restoration with Convolutional Dictionary Learning

    Shogo MURAMATSU

    APSIPA Summer School 2020  2020.12 

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  • システムと信号処理サブソサイエティの役割 ~ オンラインビデオ会議の Pros & Cons ~

    村松正吾, 高井重昌, 髙島康裕, 林 和則, 福田大輔

    電子情報通信学会CAS, VLD, SIP, MSS合同研究会  2020.6 

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  • グラフ動的モード分解による多地点河川水位の解析と予測

    新井裕介, 村松正吾, 安田浩保, 早坂圭司, 大竹 雄

    第35回信号処理シンポジウム  2020.11 

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  • 高次元信号復元のための構造化畳み込み非線形辞書

    小林累輝, 村松正吾

    第35回信号処理シンポジウム  2020.11 

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  • High-dimensional Signal Restoration by Convolutional Networks Driving Fusion Across Multiple Disciplines-Sparse Modeling and Convolutional Dictionary Learning-

    村松正吾

    映像情報メディア学会技術報告  2020 

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  • Optical coherence microscope using high-speed CMOS image sensor for intracochlear vibration imaging

    CHOI Samuel, 村松正吾, 任書晃, 太田岳, 日比野浩

    映像情報メディア学会技術報告  2020 

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  • 動的モード分解による河川データ分析

    伊郷恭平, 村松正吾, 安田浩保, 早坂圭司, CHEUNG Gene

    電子情報通信学会技術研究報告  2018.8 

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  • Development of a Cyber-Physical System for Active Control of River Channels Invited

    Shogo Muramatsu

    Technical Meeting, IEEE Sapporo Section  2021.9 

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  • 河川流路変動の解明と制御のためのサイバーフィジカルプロトタイプシステム構築

    内藤勇鷹, 村松正吾, 安田浩保, 早坂圭司, 大竹 雄

    映像情報メディア学会メディア工学研究会(サマーセミナー2020)  2020.9 

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  • 階層型冗長辞書とスケール間依存性を利用したグループスパース画像復元

    坂下和貴, 村松正吾

    映像情報メディア学会メディア工学研究会(サマーセミナー2020)  2020.9 

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  • ミリ波FM-CWレーダを用いたCNNによる人物の動作分類に関する基礎検討

    坂上史弥, 山田寛喜, 村松正吾

    電子情報通信学会宇宙・航行エレクトロニクス研究会 (SANE)  2020.6 

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  • 水制の模型実験による畳み込みスパース符号化動的モード分解の性能評価

    新井裕介, 金子侑平, 村松正吾, 安田浩保, 早坂圭司, 大竹 雄

    電子情報通信学会信号処理研究会  2020.3 

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  • 多波長走査型光コヒーレンス顕微鏡とスパースモデリングによる内耳感覚上皮帯ボリュームデータの3次元画像復元

    CHOI Samuel, 村松正吾, 太田岳, 任書晃, 鈴木孝昌, 日比野浩

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)  2019.9 

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  • レーダー画像復元のための複素ISTA組込み実装

    児玉 侑也, 吉田 祐太, 坂下 和貴, 村松 正吾, 山田 寛喜

    映像情報メディア学会技術報告  2019.8 

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  • OCT Volumetric Data Restoration with 3-D Non-separable Oversampled Lapped Transforms

    吉田 祐太, 藤井 元暉, 村松 正吾, 崔 森悦, 小野 峻佑, 太田 岳, 任 書晃, 日比野 浩

    IEICE technical report  2019.5 

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  • AIによる重症薬疹の早期診断

    藤本篤, 岩井由樹, 阿部理一郎, 村松正吾

    日本皮膚科学会雑誌  2019.5 

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  • 砂州の発生・発達過程における表面流速の計測法の開発

    茂木 大知, 五十嵐 拓実, 安田 浩保, 村松 正吾, 早坂 圭司

    第36回 土木学会関東支部新潟会研究調査発表会  2018.11 

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  • 畳込みスパース符号化を利用した拡張動的モード分解

    村松正吾, 安田浩保, 早坂圭司, 大竹雄, 小野峻佑, 湯川正裕

    第33回信号処理シンポジウム  2018.11 

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  • 重複加算/保持法を利用した生成モデルに基づく高次元信号復元処理

    吉田祐太, 藤井元暉, 村松正吾, 崔森悦

    第33回信号処理シンポジウム  2018.11 

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  • 多波長走査型光コヒーレンス顕微鏡を用いた内耳感覚上皮帯振動計

    崔森悦, 任文晃, 太田岳, 佐藤洸平, 村松正吾, 日比野浩

    日本光学会年次学術講演会予稿集  2018.11 

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  • PolSARデータを用いたサポートベクターマシンによる土地分類に関する基礎的検討

    齋藤奈々子, 山田寛喜, 村松正吾, 佐藤亮一, 山口芳雄

    電子情報通信学会信越支部大会  2018.9 

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  • 車載ミリ波SARイメージングにおけるドップラシフトの影響に関する検討

    小林拓光, 山田寛喜, 村松正吾, 山口芳雄

    電子情報通信学会信越支部大会  2018.9 

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  • 車載ミリ波SARイメージングにおけるSIMOレーダを用いた虚像抑圧に関する検討

    大島彬, 山田寛喜, 山口芳雄, 村松正吾

    電子情報通信学会信越支部大会  2018.9 

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  • 動的モード分解による河川状態のデータ駆動モデリング

    金子侑平, 安田浩保, 早坂圭司, 村松正吾

    電子情報通信学会ソサイエティ大会  2018.9 

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  • Experiment on OCT Volumetric Data Restoration via Hierarchical Sparsity and Hard Constraint

    藤井 元暉, 村松 正吾, 崔 森悦, 小野 峻佑, 太田 岳, 任 書晃, 日比野 浩

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2018.8 

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  • On Structural Constraint for Convolutional Layers in CNN

    栢森 翔太, 村松 正吾

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2018.8 

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  • Acceleration of Non-separable Oversampled Lapped Transforms for Embedded Vision

    吉田 祐太, 村松 正吾

    映像情報メディア学会技術報告 = ITE technical report  2018.8 

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  • 伝統的工芸品のBRDF圧縮センシング

    栢森翔太, 中野永人, 長山知司, 村松正吾, 阿部淑人

    2018年電子情報通信学会総合大会  2018.3 

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  • ポスター講演 複素非分離冗長重複変換を用いた超解像の検討

    長山知司, 村松正吾, 山田寛喜

    電子情報通信学会信号処理研究会  2018.3 

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  • カラー画像処理のための重複加算法による非分離冗長重複変換の組込み実装

    吉田祐太, 今井啓太, 村松正吾

    2018年電子情報通信学会総合大会  2018.3 

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  • DCGANを利用した伝統的工芸品のテクスチャ合成

    栢森翔太, 大竹加廉, 村松正吾, 阿部淑人

    2018年電子情報通信学会総合大会  2018.3 

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  • デジタルシネマの復号映像の主観品質の改善

    村田 悠, 村松正吾, 佐々木重信, 菊池久和

    第4回 明日を拓く高度情報通信シンポジウム  2017.12 

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  • 河床状態推定のための水面観測モデルの検討

    安康, 村松 正吾, 安田 浩保, 早坂 圭司

    電気学会東京支部新潟支所大会  2017.11 

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  • 交互砂州発達過程における2 次元浅水流モデルの適用性

    齋藤選, 五十嵐拓実, 安田浩保, 早坂圭司, 村松正吾

    第35回 土木学会関東支部新潟会 研究調査発表会  2017.11 

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  • 平成29年九州北部豪雨における群発表層崩壊の発生要因

    齋藤選, 五十嵐拓実, 安田浩保, 早坂圭司, 村松正吾

    第35回 土木学会関東支部新潟会 研究調査発表会  2017.11 

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  • 非負制約を利用した en-face OCTボリュームデータ信号復元

    村松正吾, 崔森悦, 小野峻佑, 伊藤迅平, 太田岳, 任書晃, 日比野浩

    第32回信号処理シンポジウム  2017.11 

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  • スパース表現による河床状態推定の検討

    伊郷恭平, 村松正吾, 安田浩保, 早坂圭司

    電子情報通信学会信越支部大会  2017.10 

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  • Study on Simple Imaging by Squint-mode SAR with Millimeter Wave Automotive Radar

    小林 拓光, 山田 寛喜, 村松 正吾, 杉山 裕一, 山口 芳雄

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2017.8 

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  • Divergence Similarity for Color Images and Its Subjective Assessment

    村山 瑞貴, 村松 正吾, 菊池 久和

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2017.6 

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  • Radar Image Denoising based on Iterative Shrinkage with Complex Nonseparable Oversampled Lapped Transforms

    長山 知司, 村松 正吾, 山田 寛喜, 杉山 裕一

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2017.6 

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  • Learning Rate Control of Nonseparable Oversampled Lapped Transform Design by Stochastic Gradient Descent

    藤井 元暉, 村松 正吾

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2017.5 

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  • Poster Presentation : On Radar Image Denoising with Complex Nonseparable Oversampled Lapped Transforms

    長山 知司, 村松 正吾, 山田 寛喜, 杉山 裕一

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2017.3 

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  • 転移学習による鎚起銅器テクスチャの合成パラメータ推定

    栢森翔太, 村松正吾, 阿部淑人

    電子情報通信学会総合大会  2017.3 

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  • Source Estimation of en-face OCT by Sparse Signal Modeling

    川村 拓海, 伊藤 迅平, 村松 正吾, 崔 森悦

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2017.1 

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  • パラメータ最適化によるen-face OCTの観測過程推定

    伊藤 迅平, 村松 正吾, 崔 森悦

    第31回信号処理シンポジウム  2016.11 

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  • en-face OCTの観測過程推定に関する検討

    伊藤 迅平, 川村 拓海, 村松 正吾, 崔 森悦

    電子情報通信学会信越支部大会  2016.10 

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  • 畳込みニューラルネットを用いた鎚起銅器テクスチャ画像の分類

    栢森 翔太, 村松 正吾, 阿部 淑人

    電子情報通信学会信越支部大会  2016.10 

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  • 板金検査システムのためのランダムドット画像によるピンホールカメラPSF推定

    王 波, 村松 正吾

    電子情報通信学会信越支部大会  2016.10 

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  • 重複加算法による非分離冗長重複変換の組み込み実装

    今井 啓太, 村松 正吾

    電子情報通信学会信越支部大会  2016.10 

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  • Poster Presentation : A Design Method of Complex Nonseparable Oversampled Lapped Transform

    長山 知司, 村松 正吾

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2016.8 

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  • 非分離冗長重複変換のHW/SW協調設計

    情野健太, 村松 正吾

    STARCフォーラム2015  2015.11 

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  • 非分離冗長重複変換の事例学習設計における効果的辞書更新

    村松 正吾, 石井 雅基

    第30回信号処理シンポジウム  2015.11 

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  • ピンホールカメラを用いた平板金属加工検査システムのための学習辞書による画像ボケ除去

    押木 友裕, 村松 正吾, 鈴木 孝昌, 村田 光由, 追立 俊朗

    第30回信号処理シンポジウム  2015.11 

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  • 多次元非分離冗長重複変換のFFT領域並列高速化

    堀内 洸汰, 村松 正吾

    第30回信号処理シンポジウム  2015.11 

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  • 学習辞書による鎚起銅器テクスチャの超解像に関する検討

    石井 雅基, 陳 智雨, 村松 正吾, 阿部 淑人

    第20回映像メディア処理シンポジウム  2015.11 

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  • 周波数領域実装による非分離冗長重複変換の並列高速化

    堀内洸汰, 村松正吾

    電子情報通信学会信越支部大会  2015.10 

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  • ピンホールカメラを用いた平板金属加工検査システムとボケ除去に関する検討

    押木友裕, 村松正吾, 鈴木孝昌, 村田光由, 追立俊朗

    電子情報通信学会信越支部大会  2015.10 

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  • 部分的間引き非分離冗長重複変換によるOCTデータノイズ除去

    川村拓海, 村松正吾, 崔森悦

    電子情報通信学会信越支部大会  2015.10 

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  • 非分離冗長重複変換の事例学習における目的関数勾配利用の検討

    石井雅基, 村松正吾

    電子情報通信学会信越支部大会  2015.10 

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  • On Application of NSOLT to 3-D OCT Data Denoising

    川村 拓海, 若杉 翔, 陳 智雨, 村松正吾, 崔 森悦

    電子情報通信学会信号処理研究会  2015.5 

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  • Poster Presentation : Computational Precision in HW/SW Co-implementation of Non-separable Oversampled Lapped Transforms

    SEINO Kenta, FURUYA Kosuke, MURAMATSU Shogo

    IEICE technical report. Signal processing  2015.3 

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    This work proposes an embedded implementation architecture of Non-separable Oversampled Lapped Transform (NSOLT) and investigates its computational precision. NSOLT satisfies the non-separable, real-valued, overlapping and compact-support property. Since the redundancy can be set to an arbitrary rational value, high performance image processing can be realized while saving memory consumption. However, NSOLT has a problem in the processing speed because of the amount of computations. It is expected to accelerate the processing speed by the HW implementation. This report proposes a HW/SW Co-implementation model of NSOLT. In addition, the bit width of integer and fractional parts are investigated to determine the optimal computational precision in the fixed-point operations.

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  • Poster Presentation : MSIST-based Image Restoration with Non-separable Oversampled Lapped Transforms

    WAKASUGI Sho, MURAMATSU Shogo

    IEICE technical report. Signal processing  2015.3 

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    This work proposes, an image restoration technique with modified subbsnd-adaptive iterative shrinkage thresholding (MSIST) and (2-D) non-separable oversampled lapped transforms (NSOLTs). An NSOLT is a lattice-structure-based redundant transform which satisfies the symmetric, real-valued and compact-support property, and capable to have rational redundancy. MSIST is an image restoration algorithm which sets a threshold for each subband independently, and allows the subband adaptive processing. In this study, the performance of the proposed method for deblurring, super-resolution and image inpainting is evaluated. It is verified that NSOLT with MSIST yields superior restoration performance to undecimated Haar transform with MSIST and NSOLT with ISTA in both of PSNR and SSIM.

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  • Image Fusion with Multiple Directional LOTs

    陳智雨, 村松正吾

    第29回信号処理シンポジウム  2014.11 

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  • ボリュームデータスパース表現のための三次元非分離冗長重複変換

    村松正吾, 古屋幸祐, 結城尚貴

    第29回信号処理シンポジウム  2014.11 

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  • 画像処理を利用した抗菌検査効果判定法

    山田孝太郎, 村松正吾, 幸田知華, 山内健, 坪川紀夫, 皆川真人

    電子情報通信学会信越支部大会  2014.10 

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  • 事例学習による非分離冗長重複変換を利用した画像ノイズ除去

    金昌吉, 村松正吾

    電子情報通信学会信越支部大会  2014.10 

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  • Structured Dictionary Learning Based on Face Images with 2-D Non-Separable Oversampled Lapped Transform

    結城 尚貴, 金 昌吉, 村松 正吾

    ITE Technical Report  2014.8 

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    本稿では,非分離冗長重複変換(NSOLT)を利用し,顔画像に基づいた構造化辞書学習を提案する.NSOLTはラティス構成に基づく変換であり,対称性・重複性を有する水平垂直非可分な要素画像(アトム)を有する.また,パーセバルタイトフレーム制約を構造的に課すことができる上,任意の有理数倍の冗長度を選択できる.本稿では,NSOLTを構造的制約とする構造化辞書学習により辞書を設計し,任意の顔画像に対して復元性能の高い辞書を設計する.また,提案法と非間引きHaar変換との顔画像復元性能を比較することで,提案辞書の性能を評価する.

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  • Implementation of Non-separable Oversampled Lapped Transforms for Embedded Vision

    古屋 幸祐, 情野 健太, 村松 正吾

    ITE Technical Report  2014.8 

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    本報告では,筆者らが提案している非分離冗長重複変換(NSOLT)の組込み実装について提案する.組込みビジョン技術の普及に伴い,車載カメラなどに用いられている組込みシステムは高性能化が望まれている.システムの性能向上の手段として,画像変換技術の高性能化が挙げられる.既存の画像変換技術として用いられている離散コサイン変換(DCT)や離散ウェーブレット変換(DWT)は,いずれも可分離処理であるため,性能向上に限界がある.そこで筆者らは,NSOLTを提案した.NSOLTは,非分離変換であり,斜め方向のテクスチャに対応できる.本報告では,NSOLTを組込みビジョン技術へ対応させるため,NSOLTの組込み実装について検討する.処理時間を測定することで,実装モデルの評価を行う.

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  • D-11-35 Study on Sheet-Metal Inspection System Using A Multi-Camera Array

    Chen Yangchao, Terasawa Norihisa, Muramatsu Shogo, Suzuki Takamasa, Oitate Toshiro

    Proceedings of the IEICE General Conference  2014.3 

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  • A-4-23 Heuristic Shrinkage Image Denoising with Non-separable Oversampled Lapped Transform

    Wakasugi Sho, Aizawa Natsuki, Muramatsu Shogo

    Proceedings of the IEICE General Conference  2014.3 

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  • A-4-25 HW/SW Co-Design of Non-separable Oversampled Lapped Transform

    Seino Kenta, Furuya Kosuke, Hara Shintaro, Muramatsu Shogo

    Proceedings of the IEICE General Conference  2014.3 

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  • D-11-34 Scale Correction in Sheet-Metal Inspection System with Digital Camera

    Oshiki Tomohiro, Terasawa Norihisa, Muramatsu Shogo, Suzuki Takamasa, Oitate Toshiro

    Proceedings of the IEICE General Conference  2014.3 

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  • クラス判別のための部分和による境界演算

    渡辺秀典, 村松正吾

    第28回信号処理シンポジウム  2013.11 

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  • Anscombe 変換に基づく混成DirLOTを利用したポアソンノイズ除去

    陳 智雨, 村松 正吾

    第28回信号処理シンポジウム  2013.11 

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  • Embedded Implementation Model of Non-separable Symmetric Lapped Transforms

    古屋 幸祐, 原 伸太郎, 渡辺 秀典, 村松 正吾

    第28回信号処理シンポジウム  2013.11 

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  • プロジェクトの企画運営における多角的視点と工学以外の知識の役割

    谷口諒太郎, 島田泰奨, 村松正吾, 佐々木重信, 原伸太郎

    日本工業教育協会年次大会  2013.8 

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  • 非分離冗長重複変換による高圧縮JPEG/JPEG2000画像の復元(若葉研究者の集い6,サマーセミナー2013〜画像処理の理論と実際〜)

    稲田 岳, 相澤 夏希, 村松 正吾

    映情学技報  2013.8 

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    本報告では,先に筆者らが提案した指向性を持つ非分離冗長重複変換(NSOLT)による高圧縮JPEG/JPEG2000画像の復元法を提案する.NSOLTは非分離処理であり,指向性を有するほか,2倍以下の有理数の冗長度を持つことができる.これまでに変換と繰返し縮退/閾値処理アルゴリズム(ISTA)を用いた画像復元法が高い性能を示すことを確認している.本稿ではJPEG/JPEG2000の劣化過程を線形システムでモデル化し,従来の枠組みで画像復元を行い,性能を評価する.

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  • Embedded Implementation of 2-D Nonseparable Linear-Phase Paraunitary Filter Bank with Multi-Level Tree Structure

    古屋 幸祐, 原 伸太郎, 村松 正吾

    回路とシステムワークショップ論文集 Workshop on Circuits and Systems  2013.7 

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  • ワンショットデジタルカメラを利用した平板金属検査システムにおける操作性向上の研究

    結城尚貴, 村松正吾, 鈴木考昌, 渡辺秀典, 寺澤憲久, 姚海, 追立俊明

    第19回画像センシングシンポジウム(SSII2013)  2013.6 

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  • Image Restoration with Directional Non-separable Oversampled Lapped Transform

    AIZAWA Natsuki, MURAMATSU Shogo

    IEICE technical report. Signal processing  2013.3 

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    This report proposes an image restoration technique with directional non-separable oversampled lapped transform (NSOLT)that the authors suggested as a previous work. NSOLT is a non-separable transform, able to possess a directional property, and capable to have rational redundancy less than two. In this report, the proposed transform is applied to deblurring, super-resolution and inpainting, and the performance is evaluated. The image restoration performance is compared with that of the redundant Haar transform as another redundant system. From simulation results, it is verified that the proposed method not only yields visually preferable results, but also shows high performance in terms of objective criteria, PSNR and SSIM.

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  • Motion-Compensated Temporal Filtering for Remote Control of Microscope

    TUERXUN Aishan, CHEN Zhiyu, MURAMATSU Shogo

    ITE Technical Report  2013.2 

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    In order to realize an efficient remote control of microscope for medicine, a lossless/lossy image sequence codec system is proposed by adopting motion-compensated temporal filtering (MCTF) and Motion JPEG2000. The proposed system exploits information of translation command as a motion vector given from the remote operator for searching a region of interest, and applies a global motion-compensation (GMC) to even frames. The GMC frames are used to predict odd frames in the temporal lifting structure and the difference is transmitted as an enhancement layer. In the static case, the base layer consisting of even frames and enhancement layer consisting of the difference are completely used to realize the lossless decode. On the other hand, when searching a region of interest, only the base layer is employed so that lossy decoding is realized for reducing the transmission cost. As a result, the usability is improved. In this report, the basic structure is investigated and verified the significance of the scalability function according to the static and dynamic operation case.

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  • Kinect-Based Gesture Recognition for Metal Sheet Inspection System

    YAO Hai, TERASAWA Norihisa, MURAMATSU Shogo, SUZUKI Takamasa, OITATE Toshiro

    ITE Technical Report  2013.2 

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    A metal sheet inspection system with Kinect is introduced in this work. The current sheet metal inspection system which the authors have proposed consists of an inspecting table and operation terminal. Since the table and terminal are separately installed, it is obliged to useless operations. In order to solve this problem, it is proposed to introduce a gesture recognition function of the Kinect sensor and improve the usability. A depth image is acquired by using Kinect, and then a fundamental gesture recognition is realized by using the OpenNI function. The fundamental gestures are considered to be adopted to the inspection operation terminal and the gesture operation on the inspecting table is discussed.

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  • 6-217 Role of Various Viewpoints and Knowledge Away from Engineering in a Project Management

    TANIGUCHI Ryotaro, SHIMADA Taisuke, HARA Shintaro, MURAMATSU Shogo, SASAKI Shigenobu

    Proceedings of Annual Conference of JSEE  2013 

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  • A Lattice Structure for 2-D Non-Separable Discrete Symmetric Tight Frames

    村松 正吾, 相澤 夏希

    信号処理シンポジウム講演論文集  2012.11 

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  • Tree Structure and Embedded Implementation of Directional Lapped Orthogonal Transforms

    原 伸太郎, 古屋 幸祐, 村松 正吾

    信号処理シンポジウム講演論文集  2012.11 

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  • A Study on Color Similarity between Digital Images

    片岡 智, 菊池 久和, 村松 正吾

    信号処理シンポジウム講演論文集  2012.11 

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  • カラー画像の類似性計量について

    片岡 智, 菊池 久和, 村松 正吾, ヘイッキ・フットネン

    2012年度画像符号化シンポジウム  2012.10 

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  • 透過型平板金属加工検査システムのためのレンズ歪補正に関する検討(若葉研究者の集い2,サマーセミナー2012〜高精細化時代のビジョン技術〜)

    寺澤 憲久, 北澤 伸哉, 渡辺 秀典, 村松 正吾, 鈴木 孝昌, 村田 光由, 追立 俊朗

    映情学技報  2012.8 

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    本研究では,デジタルカメラを用いた高精度且つ低コストな板金検査システムを提案する.提案検査システムは単一のデジタルカメラにより板金の画像を取得し,設計データと比較することで板金の加工誤差を検出する.デジタルカメラにより取得した画像はレンズ歪を有するため,高精度検査システムの実現にはレンズ歪の推定及び補正が必要となる.また,台座の高さや板金の厚みによるズレも考慮する必要がある.本研究では半径歪モデルと位相限定相関法を組み合わせた歪推定,局所的射影変換を用いた歪補正及び高さ・厚み補正の方法を提案する.実験により提案検査システムの検査精度を評価し,精度0.5mmの達成を確認する.

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  • Filtering, Transform and Sparse Representation of Images Invited

    村松 正吾

    回路とシステムワークショップ論文集 Workshop on Circuits and Systems  2012.7 

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  • ISTA-Based Image Restoration with Multiple DirLOTs

    相澤 夏希, 村松 正吾, 湯川 正裕

    回路とシステムワークショップ論文集 Workshop on Circuits and Systems  2012.7 

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  • Hardware Model of Two-Dimensional Non-separable GenLOT for Video Processing

    HARA Shintaro, OTA Yuya, MURAMATSU Shogo

    IEICE technical report. Signal processing  2012.3 

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    In this report, a hardware model of two-dimensional non-separable GenLOT for video processing and a permutation module for wavelet structure are proposed. Existing transforms such as the discrete cosine trnsform (DCT) and discrete wavelet transform (DWT) are not suitable for the expression of diagonal edges or textures because these transforms are separable. The directional GenLOT proposed in this laboratory is suitable for the expression because it is non-separable. However, there is a problem of the processing speed in the directional GenLOT. It is expected that the specific hardware is effective to solve this problem. Therefore, the authors proposed a hardware model of two-dimensional non-separable GenLOT, where the model is designed for a still image processing. This study suggests to extend the hardware model to video processing of two-dimensional non-separable GenLOT by the modifying the preceding model. In addition, a module for wavelet structure is also proposed. Finally, a part of the model is described by VHDL, and the speed and area are evaluated in order to show the significance of the proposed architecture.

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  • Geometrical Distortion Estimation and Compensation for High Precision Metal Sheet Inspection System with Digital Still Camera

    KITAZAWA Shinya, WASHIZU Toru, WATANABE Hidenori, SATO Kotaro, TERASAWA Norihisa, HIROSAWA Akira, MURAMATSU Shogo, SUZUKI Takamasa, MURATA Mitsuyoshi, OITATE Toshiro

    IEICE technical report. Signal processing  2012.3 

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    In this report, a fast and automatic metal sheet inspection system by digital still camera is introduced. This system acquires a metal sheet image with a single digital still camera, inspects the image and detects errors by comparing with the layout data. Since a digital still camera yields particular lens distortions, geometrical undistortion process is required in order to achieve high precision inspection. In this research, it is proposed to combine the camera calibration with a radial distortion model and residual detail variation in order to achieve high precision distortion estimation. After undistortion by the radial distortion model, the detail variation is estimated by phase only correlation(POC). Futhermore, errors resulted from thickness of metal sheet is also compensated simultaneously. In order to confirm the significance of this inspection system, the accuracy is evaluated.

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  • Image Restoration with Union of Multiple DirLOTs

    AIZAWA Natsuki, MURAMATSU Shogo

    IEICE technical report. Signal processing  2012.3 

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    In this report, an image restoration method by using Directional Lapped Orthonormal Transform (DirLOT), which the authors proposed previously, is investigated. The transform has an advantage in representing diagonal edges and textures in images because it is nonseparable processing and has directional property. This study, suggests to construct a redundant dictionary which has multiple directional property by using multiple directional symmetric orthonormal wavelet transform(DirSOWT). The multiple directional property is suitable for representing a natural picture containing diagonal geometrical structures. The dictionary is applied to image restoration and the performance is evaluated. In order to show the significance of the proposed method, the performance is also compared with the image restoration results through non-subsampled Haar transform. It is confirmed that the proposed method yields perceptually preferable results from experimental results.

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  • 区間計算を用いた混合ガウス分布モデルクラス判別器による誤り訂正出力符号

    渡辺秀典, 村松正吾, 菊池久和, 佐々木重信

    第26回信号処理シンポジウム  2011.11 

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  • 混成指向性重複直交変換を利用した画像ノイズ除去

    韓丹丹, 村松正吾

    第26回信号処理シンポジウム  2011.11 

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  • 口腔悪性腫瘍における病理診断サポートのための口腔病理画像解析

    田中良祐, 菊池久和, 朔敬, 村松正吾, 湯川正裕, Mustafa M. Sami

    第26回信号処理シンポジウム  2011.11 

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  • 画像処理によるはんだ付け外観検査のための特徴量削減と良否識別

    今井達也, 菊池久和, 村松正吾, 湯川正裕

    第26回信号処理シンポジウム  2011.11 

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  • QuadtreeとSBCを用いた高能率プログレッシブ画像圧縮符号化

    阿部亮介, 菊池久和, 村松正吾, 湯川正裕

    第26回信号処理シンポジウム  2011.11 

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  • A Study on Edge-Aware Local/Global Tone Mapping for High Dynamic Range Compression

    黄正顕, 菊池久和, 村松正吾

    第26回信号処理シンポジウム  2011.11 

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  • 位相差顕微鏡映像における歯周病菌の追跡について

    川村陽一, 菊池久和, 村松正吾, 湯川正裕

    第26回信号処理シンポジウム  2011.11 

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  • 混成指向性重複直交変換を利用した画像スパース表現

    武田一樹, 村松正吾

    第26回信号処理シンポジウム  2011.11 

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  • デジタルカメラを利用した透過型板金検査システム

    寺澤 憲久, 北澤 伸哉, 渡辺 秀典, 村松 正吾, 鈴木 孝昌, 村田 光由, 追立 俊朗

    DSPS教育会議  2011.9 

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  • 映像処理のための非分離重複直交変換の組込み実装

    古屋 幸祐, 原 伸太郎, 村松 正吾

    DSPS教育会議  2011.9 

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  • シフト不変二次元非分離GenLOTを用いた平坦領域検出(若葉研究者の集い2,サマーセミナー2011(若葉研究者の集い))

    本田 義文, 村松 正吾, 村田 光由, 追立 俊朗

    映情学技報  2011.8 

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    本研究では,二次のバニッシングモーメントを有するシフト不変二次元非分離GenLOTの平面分離性能を利用し,画像中から平坦な領域を検出する手法を提案する.本手法は,教室における黒板・ホワイトボード領域検出や板金端材の未使用領域検出などの応用が期待される.検出法として,シフト不変二次元非分離GenLOTを用いてエネルギーマップを作成し,このエネルギーマップからマスクを求め,非平坦領域の削除・モルフォロジー処理を行うことで領域分割を行う.Haar DWT,9/7DWTを利用した結果との比較を通して本提案法の有効性を確認する.

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  • 3-6 On Adaptive Basis Switch Coding with 2-D Non-separable GenLOT

    WANG Rui, MURAMATSU Shogo, KIKUCHI Hisakazu

    PROCEEDINGS OF THE ITE ANNUAL CONVENTION  2011.8 

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    This report proposes an adaptive basis switching technique of two-dimensional (2-D) non-separable (NS) GenLOT for picture coding. The conventional DCT and DWTs are separable and have disadvantage in representing diagonal edges and textures of a given picture. In order to overcome the problem, the authors proposed 2-D NS GenLOT as a previous work. In this work, the adaptive local basis control of overlap and direction is investigated and the significance is verified.

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  • SURE-LET Image Denoising Through 2-D Non-separable GenLOT

    HAN Dandan, MURAMATSU Shogo, KIKUCHI Hisakazu

    IEICE technical report  2011.6 

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    This work proposes a denoising technoque with a two-dimensional (2-D) non-separable GenLOT for image denoising. In image denoising, one of the most popular and well known techniques is the soft shrinkage proposed by Donoho and Johnstone. However, the shrinkage function is not flexible since it depends on the universal threshold and the non-linearity makes the optimization complex. In order to mitigate these problems, an orthonormal wavelet thresholding algorithm based on SURE-LET is proposed by Luisier. However, the method still has a disadvantage in representing diagonal geometric structures such as diagonal edges and textures due to the separablity of an adopted transform. In order to solve the problem, this work contributes to apply the 2-D non-separable GenLOT with the trend vanishing moments(TVMs). From some experimental results, it is shown that our proposed method shows better performance for diagonal texture images.

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  • Hardware Implementation of Two-Dimensional Non-separable GenLOT Based on Block Processing and Lifting Scheme

    OTA Yuya, CHOI Saemi, MURAMATSU Shogo, KIKUCHI Hisakazu

    IEICE technical report  2011.6 

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    In this report, a hardware architecture of two-dimensional non-separable GenLOT is proposed based on the block processing and lifting scheme. The discrete cosine transform (DCT) adopted in JPEG and MPEG-2, or the discrete wavelet transform (DWT) used in JPEG2000 are not suitable for the expression of diagonal textures and edges because these transforms are separable. The non-separable GenLOT proposed by the authors is suitable for the expression of diagonal textures and edges because it can take directionality and has block-wise implementation which maintains the orthogonality. However, there is a problem in the process in teams of the computational cost. It is expected that a specific hardware yields effective solution to this problem. Therefore, in this study, it is suggested to realize the two-dimensional non-separable GenLOT on hardware architecture by the block-wise handling and lifting scheme. The circuit module to be implemented on hardware is modeled by VHDL and the speed and area are evaluated from the synthesis reports.

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  • フィルムグレイン再現モデルとディジタルシネマへの適用

    宗形俊, 菊池久和, 村松正吾, 湯川正裕, ヘイッキフットネン

    第25回信号処理シンポジウム  2010.11 

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  • TV Image Denosing and Noise Response Analysis

    Peter Ndajah, Masahiro Yukawa, Shogo Muramatsu, Hisakazu Kikuchi

    25th IEICE Signal Processing Symposium  2010.11 

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  • 区間計算を用いた混合ガウス分布モデルクラス判別器によるAdaboost

    渡辺秀典, 村松正吾, 菊池久和

    第25回信号処理シンポジウム  2010.11 

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  • 指向性GenLOTによる傾斜平面方向検出

    村松正吾, 韓丹丹, 小林智也, 菊池久和

    第25回信号処理シンポジウム  2010.11 

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  • 固定小数点精度におけるHough曲線計算の誤差評価

    鷲津亨, 村松正吾, 菊池久和

    電子情報通信学会信越支部大会  2010.10 

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  • Surface Annihilation Property of Trend Vanishing Moments

    Dandan Han, Tomoya Kobayashi, Shogo Muramatsu, Hisakazu Kikuchi

    電子情報通信学会ソサイエティ大会  2010.9 

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  • RAGアルゴリズムによる混合ガウス分布のための二次形式計算回路の小面積回路実装

    高橋充, 村松正吾, 菊池久和

    DSPS教育者会議  2010.9 

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  • P-14 Good Practice for Education "Departure from Superficial Learning" : Case in Electrical and Electronic Engineering Design Education

    OHDAIRA Yasuo, MURAMATSU Shougo, SHINBO Kazunari, FUKUI Satoshi, SUZUKI Takamasa

    工学・工業教育研究講演会講演論文集  2010.8 

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  • Adaptive Parameter Control and Block-Wise Implementation of Directional GenLOT

    皆川 明樹, 村松 正吾, 小林 智也, 菊池 久和

    ITE Technical Report  2010.8 

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    本研究では,筆者らが先に提案した指向性GenLOTにおける適応的パラメータ制御とブロック処理について述べる.これまで筆者らは,一定の方向を持つ画像に指向性GenLOTを適用することにより符号化性能を示してきた.そこで,今回はフィルタを適応的に切り替えることにより,様々な方向を持つ画像に対する指向性GenLOTの適用を試みる.符号化実験を通して本適応型指向性GenLOTの有効性を確認する.

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  • Relation between Keypoint Detection Ratio and Fixed-Point Word Length in SIFT Algorithm

    Nagumo Koji, Muramatsu Shogo, Kikuchi Hisakazu

    ITE Technical Report  2010.8 

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    本研究では,SIFTアルゴリズムにおけるキーポイントの検出精度と,固定小数点数の演算語長の関係を検証する.小数部の演算語長に24ビットを割り当てることで,誤検出数を2%,検出漏れ数を0.9%に抑えることが出来た.

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  • A Proposal of a Reproduction Model of Film Grain Textures in Decoding of Digital Cinema

    Munekata Shun, Kikuchi Hisakazu, Muramatsu Shogo, Yukawa Masahiro

    ITE Technical Report  2010.8 

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    ディジタルシネマのJPEG2000圧縮符号化に際してビットレートが十分に高くない場合,フィルム映画特有の質感を表わすフィルムグレインテクスチャが喪失する.本稿では,喪失フィルムグレインテクスチャを復号時に再現するためのモデルを提案する.フィルムグレインの統計的特徴にもとづいてモデル化を行い,白色雑音の混合,補間,明度依存画素適応振幅制御によってフィルムグレインテクスチャを再現する.実験的に提案モデルの妥当性を検証する.

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  • Reversible Component Transforms via an Interpretation of the LU Factorization

    KIKUCHI Hisakazu, HWANG Junghyeun, MURAMATSU Shogo

    IEICE technical report  2010.6 

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    A variant to a given irreversible linear transformation is defined based on the LU decomposition of a nonsingular matrix so that the transformation may be computed in a lifting form and may be hence reversible. Round-off errors involved with the lifting computation and the signal excursion are analyzed, and the computational complexity is also given. Some reversible component transforms are presented and experimented to provide helpful information to image compression applications. Discussions are developed with coding gain and actual bit rates.

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  • エアフローのあるダクトにおける能動騒音制御の検討

    吉田隆広, 広田俊介, 藤原武士, 羽田卓史, 菊池久和, 村松正吾

    電子情報通信学会総合大会  2010.3 

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  • Directional Constraints for 2-D Non-separable GenLOT

    KOBAYASHI Tomoya, MURAMATSU Shogo, KIKUCHI Hisakazu

    IEICE technical report. Signal processing  2010.2 

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    This paper proposes the diretional vanishing moment constraints to two-dimentional (2-D) non-separable GenLOT. As a previous work, the authors have proposed a lattice structure of 2-D non-separable filter banks which are orthogonal, symmetric and have overlapping property, and been investigated the directional design. This work newly derives directional constraints for parameter matrices of the lattice structure, which is given by introducing directional derivation to the transfer functions. Some experimental results of texture coding show the significance of the novel constraints.

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  • 指向性GenLOTにおける基底設計とブロック処理

    小林智也, 村松正吾, 菊池久和

    第24回信号処理シンポジウム  2009.11 

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  • 位相差顕微鏡映像における歯周病菌の追跡

    皆川圭, 菊池久和, 村松正吾

    第24回信号処理シンポジウム  2009.11 

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  • 混合ガウス分布モデルのための区間計算に基づくEMアルゴリズム

    渡辺秀典, 村松正吾, 菊池久和

    第24回信号処理シンポジウム  2009.11 

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  • A-4-16 On Directional Design of GenLOT for Picture Coding

    Sano Makoto, Hiki Minoru, Muramatsu Shogo, Kikuchi Hisakazu

    Proceedings of the Society Conference of IEICE  2009.9 

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  • A-4-10 Area Reduction of Quadratic Form Calcurator with Modified Distributed Arithmetic

    Nagumo Koji, Muramatsu Shogo, Kikuchi Hisakazu

    Proceedings of the Society Conference of IEICE  2009.9 

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  • A-4-9 GMM-based Classification with Interval Calculation using Multiplierless Refinement Scheme

    Watanabe Hidenori, Muramatsu Shogo, Kikuchi Hisakazu

    Proceedings of the Society Conference of IEICE  2009.9 

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  • A-4-17 Boundary Operations for Directional GenLOT

    Kobayashi Tomoya, Hiki Minoru, Muramatsu Shogo, Kikuchi Hisakazu

    Proceedings of the Society Conference of IEICE  2009.9 

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  • A-4-18 Fixed-point Design of Directional Interpolation Filter without Checkerboard Effect

    Minagawa Haruki, Muramatsu Shogo, Kikuchi Hisakazu

    Proceedings of the Society Conference of IEICE  2009.9 

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  • A-4-35 Adaptive Spatio-temporal Filtering with Motion/Edge Detecter

    Sato Kazuya, Hiki Minoru, Muramatsu Shogo, Kikuchi Hisakazu

    Proceedings of the Society Conference of IEICE  2009.9 

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  • A-4-39 A Design of an Active Noise Control Unit for a Duct

    Hirota Shunsuke, Yoshida Takahiro, Fujiwara Takeshi, Haneda Takuji, Kikuchi Hisakazu, Muramatsu Shogo

    Proceedings of the Society Conference of IEICE  2009.9 

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  • A-4-7 Error Evaluation of Markov Chain Monte Carlo with Chebyshev Approximation

    Kikuchi Yuji, Muramatsu Shogo, Kikuchi Hisakazu

    Proceedings of the Society Conference of IEICE  2009.9 

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  • A-4-8 Performance Evaluation of Interval Calculation with Fixed Point Arithmetic for GMM-Based Classifier

    Sato Takahiro, Watanabe Hidenori, Muramatsu Shogo, Kikuchi Hisakazu

    Proceedings of the Society Conference of IEICE  2009.9 

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  • グリーンノイズによる印刷向けハーフトーニングに関する研究

    林友之, 菊池久和, 村松正吾

    電子情報通信学会ソサイエティ大会  2009.9 

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  • 修正型分散算術による二次形式計算回路の面積削減

    南雲康次, 村松正吾, 菊池久和

    第11回DSPS教育者会議  2009.9 

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  • 指向性GenLOTにおける境界処理(セッション4,サマーセミナー(若葉研究者の集い))

    小林 智也, 比企 豊, 村松 正吾, 菊池 久和

    映情学技報  2009.8 

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    本研究では,指向性GenLOTにおける境界処理について述べる.JPEGやMPEG-2で採用されている離散コサイン変換(DCT)はブロック歪が発生するという問題がある.JPEG2000では基底画像が重複性を持つ離散ウェーブレット変換(DWT)を採用し,ブロック歪を回避している.これらDCT,DWTは可分離処理のため,画像の斜めエッジに適していない.そこで筆者らは指向性GenLOT/DWTを提案している.この変換は指向性設計が可能で,基底画像が重複性を有するためブロック歪を起こさない.しかしながら,対称拡張による境界処理ができず実際の画像処理への妨げとなっていた.本報告では,ラティス構成のパラメータ制御によって,基底画像の重複性を制御可能であることを示し,指向性GenLOT/DWTにおける境界処理が可能となることを示す.

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  • Effective Features for Defective Soldering Detection by Image Analysis

    SUGIYAMA Kentaro, MIYAGUCHI Tatsuya, KIKUCHI Hisakazu, MURAMATSU Shogo, KOBAYASHI Jun-ichi

    Reports of the Technical Conference of the Institute of Image Electronics Engineers of Japan  2009.7 

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    In the optical soldering inspection systems, the existence or nonexistence of soldering paste and unfirm solder are relatively easy to be detected. However, it is difficult to classify the amount, the shape and the state of the fillet of brazed joints. This study aims at a development of an automatic classification system of solder joints on printed circuit boards and an exploration of effective features for defective soldering detection by means of statistical image analysis of digital images. A number of features are selected from textural features to be tested for the classification into 5 typical classes of solder joints. Experiments have shown that they are effective.

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  • 区間計算を用いた混合ガウス分布モデルに基づくクラス判別のDSP/FPGA実装

    渡辺秀典, 村松正吾, 菊池久和

    第22回回路とシステム軽井沢ワークショップ  2009.4 

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  • Second Vanishing Moment Constraints on 2-D GenLOT and Its Directional Design

    MURAMATSU Shogo, ADACHI Atsuyuki

    ITE Technical Report  2008.12 

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    This work proposes a novel design method of 2-D non-separable linear-phase paraunitary filter banks (LPPUFB). Especially the two-degree vanishing moment constraint is derived for the lattice structure. In the 2 × 2-decomposition case, the authors have already derived the constraint and designed non-separable symmetric orthonormal wavelets with vanishing moments of degree two. This work extends the discussion to more general 2m_y × 2m_x-decomposition case and yields a method to impose the condition to the lattice structure. The constraint is imposed directly on design parameters so that both of the linear-phase and paraunitary property are structurally guaranteed. Since the structure adopted in this work is based on the 2-D separable DCT, 2-D separable GenLOT, a popular lattice structure of DCT-based LPPUFB, is regarded as a special case. The main advantage of non-separable systems is the directional capability. This work allows us to obtain directional non-separable LOT with two-degree vanishing moments. Some design examples are shown to verify the significance of the proposed method.

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  • Directional Adaptive Nonseparable Interpolation Filter for Sub-pixel Motion Compansation

    HIKI Minoru, MURAMATSU Shogo, KIKUCHI Hisakazu

    ITE Technical Report  2008.12 

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    In this work, we evaluate the directional adaptive nonseparable interpolation filter for sub-pixel motion compensation. In the future video coding systems, developing more efficeient interpolation filter for motion compensation is impotant subject to implove coding efficiency. In this work, we develop some nonseparable interpolation filters support different frequency region, and propose a new edge adaptive nonseparable interpolation method altering the filter by edge direction. Simulation for simple edge images and coding experiments for real video are shown.

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  • 画素の復号期待値によるビットモデリングにもとづく汎用ビットプレン符号化

    菊池久和, 船橋邦夫, 村松正吾

    第23回信号処理シンポジウム  2008.11 

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  • 色相変化に着目した高忠実度カラーデモゼイシング

    大野寛仁, 菊池久和, 村松正吾

    第13回映像メディア処理シンポジウム (PCSJ/IMPS)  2008.10 

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  • 動き補償時空間フィルタリングにおける可変係数型可逆デインタレース処理のパラメータ非伝送化

    打田淳, 村松正吾, 菊池久和

    第23回画像符号化シンポジウム (PCSJ/IMPS)  2008.10 

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  • 復号画素値を文脈とするビットプレン符号化 -機能拡充型可逆画像圧縮-

    船橋邦夫, 菊池久和, 村松正吾

    第23回画像符号化シンポジウム (PCSJ/IMPS)  2008.10 

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  • A-4-5 Interval Calculation with Fixed Point Arithmetic for Classification of Gaussian Mixture Models

    Sato Takahiro, Muramatsu Shogo, Watanabe Hidenori, Kikuchi Hisakazu

    Proceedings of the Society Conference of IEICE  2008.9 

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  • 混合ガウス分布モデルの区間計算判別回路におけるダイナミックレンジの改善

    渡辺秀典, 村松正吾, 菊池久和

    電子情報通信学会信越支部大会  2008.9 

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  • はんだ付け外観検査装置のための高次局所自己相関特徴を用いたはんだ画像の識別

    宮口竜也, 菊池久和, 村松正吾, 小林淳一

    第10回DSPS教育者会議  2008.9 

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  • デジタルシネマ復号映像におけるフリッカ低減方法

    村田悠, 菊池久和, 村松正吾

    第10回DSPS教育者会議  2008.9 

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  • 区間計算法を用いた混合ガウス分布モデルの判別回路の実装

    渡辺秀典, 村松正吾, 菊池久和

    第10回DSPS教育者会議  2008.9 

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  • 回帰分析を用いた河川監視映像のための河川水位推定

    大倉誠, 村松正吾, 岩橋政宏

    電子情報通信学会信越支部大会  2008.9 

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  • ラティス構成に基づく指向性フィルタバンク設計の検討(サマーセミナー(若葉研究者の集い)「最先端ビジョン技術が拓く画像応用の新境地」)

    安達 充幸, 村松 正吾, 菊池 久和

    映情学技報  2008.8 

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    本研究では,筆者らが既に提案しているラティス構成に基づく多次元直線位相直交フィルタバンクの設計法を用いて,指向性を考慮した二次元直交対称ウェーブレット変換の設計法を検討する.異方性の自己相関関数モデルに対する最適化設計をとおして,2次のバニッシング・モーメントを持つ指向性フィルタバンクの設計を行い,シミュレーションによる性能評価を行う.

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  • Progressive Bitplane Coding for Lossless Image Compression

    FUNAHASHI Kunio, KIKUCHI Hisakazu, MURAMATSU Shogo

    IEICE technical report  2008.6 

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    A lossless compression system for digital images is proposed to equip itself with two functions of progressive transmission and progressive decoding. It is a bitplane coding system and consists of context modeling and adaptive arithmetic coding (actually range coding). Starting from the most significant bitplane, every bitplane is encoded into a separate bit stream to implement progressive transmission. Sequential encoding of bitplanes enables progressive decoding. The context of a target bit is made of two composites. The neigborhood context is modeled by the expectation values of the neighboring pixel values that are available at decoders. The other is the self context that is the MSB of the decode expectation value for the target pixel. The lossless compression performance of the bitplane codec is competitive with that of JPEG-LS. There is no spatial blur even at the earliest level of progressive decoding. The mean square error between the original image and a decoded image at any progression level is known prior to encoding/decoding.

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  • Tracking of Periodontal Bacteria in Phase-Contrast Microscopic Video

    SHIMIZU Keita, KIKUCHI Hisakazu, MURAMATSU Shogo

    IEICE technical report  2008.6 

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    The latest research shows that 80 percents of the Japanese adult are infected by a periodontal disease. The pathological study on live periodontal bacteria has been not yet developed at a sufficient level for finding treatments and preventions against the periodontal disease. It is useful to design an automatic system that analyzes the live bacterial activity and dynamics in the mouth. This study presents an approach for analyzing the bacterial activity on a video sequence acquired by a differential phase microscope. By using a moving object segmentation algorithm, it has been successful to remove the background out of the video sequence and to detect moving bacteria. Bacteria are extracted by labeling connected pixels, and their locations and shapes are identified for tracking moving bacteria. The periodontal bacteria tracking system has been implemented on a digital signal processor (DSP) for real-time processing. The system offers two tracking modes: tracking all individual bacteria and tracking a single specific bacterium.

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  • An LSI architecture of classification module for Gaussian mixture models with interval computations

    武田 竜之介, 村松 正吾, 高橋 祐一郎

    回路とシステム軽井沢ワークショップ論文集  2008.4 

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  • D-16-8 Image Processing for Assisting the Diagnosis of Oral Pathological Images

    Saito Masahisa, Kikuchi Hisakazu, Muramatsu Shogo, Saku Takashi

    Proceedings of the IEICE General Conference  2008.3 

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  • A-4-20 An Efficient Classification Module Based on Gaussian Mixture Models with Interval Calculation

    Takeda Ryunosuke, Muramatsu Shogo, Watanabe Hidenori, Kikuchi Hisakazu

    Proceedings of the IEICE General Conference  2008.3 

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  • D-12-110 A Classification of Solder Appearance Using Higher-order Local Autocorrelation Features

    Miyaguchi Tatsuya, Kikuchi Hisakazu, Muramatsu Shogo, Kobayashi Jyunichi

    Proceedings of the IEICE General Conference  2008.3 

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  • Efficient Classification for Gaussian Mixture Models with Interval Calculation

    MURAMATSU Shogo, WATANABE Tsutomu, WATANABE Hidenori

    IEICE technical report  2008.1 

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    This work proposes an efficient Bayesian decision scheme for Gaussian mixture models (GMM). Statistical pattern classification problems with the Bayesian decision theorem often meet a situation that comparison between posterior probabilities of classes is obvious. In this work, the comparison for GMM is reduced to simple interval calculations. The exponential function is replaced by scaling and multiplication with powers of two, and the decision if teh comparison is obvious and which class is most likely is efficiently calculated. For unclear cases, a refinement process is also proposed, where the computational accuracy is successively refined. In order to verify the significance, experimental results of the application to a skin color classifier are shown. It is shown that the classification for over 99.5% of all observed data was completed without any refinement process, and that the refinement process was able to complete all decision. The proposed method enables us to save redundand exponential operations and is expected for DSP or LSI implementation with low power consumption.

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  • Coefficient parameter reduction of invertible deinterlacing in motion-compensated spatiotemporal filtering

    岡田 敏幸, 村松 正吾, 比企 豊

    ITE technical report  2007.12 

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  • 単板式ディジタルカメラのための高忠実度カラーデモゼイシング

    大野寛仁, 高橋善寿, 村松正吾, 佐々木重信, 菊池久和

    第4回 明日を拓く高度情報通信シンポジウム  2007.12 

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  • デジタルシネマの復号映像の主観品質の改善

    村田 悠, 村松正吾, 佐々木重信, 菊池久和

    第4回 明日を拓く高度情報通信シンポジウム  2007.12 

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  • A Proposal of Directional Interpolation for Digital Halftone Printing

    IIJIMA Akira, KIKUCHI Hisakazu, MURAMATSU Shogo

    IEICE technical report  2007.11 

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    Bilevel halftones are used for printing color digital images. The interpolation of color pixel values prior to digital halftoning is discussed and a new color interpolation scheme is presented by a directional copy of color values in the hue vector space. As the number of data increases due to the interpolation, contouring artifacts are likely to appear because similar values increase in the close vicinity over uniform areas. Error diffusion is incorporated with the clustered-dot ordered dithering to prevent from undesirable contouring. Experimental results demonstrate that sharp interpolation is obtained to produce no visible contouring artifacts.

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  • Design of Non-separable Orthogonal Symmetric Wavelets With a Lattice Structure

    MURAMATSU Shogo, ADACHI Atsuyuki, KIKUCHI Hisakazu

    IEICE technical report  2007.11 

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    In this work, a design method of two-dimensional (2-D) orthogonal symmetric wavelets is proposed by using a lattice structure for multi-dimensional (M-D) linear-phase paraunitary filter banks (LPPUFB), which the authors have proposed before as a previous work. The derivation process for the constraints on the second-order vanishing moment is shown and some design examples obtained through optimization with the constraints are exemplified. In the application to image processing, the directionality of filters is of interest. This report verifies through optimization processes for anisotropic autocorrelated function (acf) model that the vanishing moment constraints significantly influence to the directionality.

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  • 定色相原理に基づく補間方向推定を用いたカラーデモゼイシング

    大野寛仁, 高橋善寿, 菊池久和, 村松正吾

    第22回信号処理シンポジウム  2007.11 

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  • 可変係数型可逆デインタレース処理のパラメータ非伝送化

    打田淳, 村松正吾, 菊池久和

    第22会画像符号化シンポジウム(PCSJ/IMPS)  2007.11 

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  • MCSTFにおける可変係数可逆デインタレース処理のためのパラメータ間引き

    岡田敏幸, 比企豊, 村松正吾, 菊池久和

    電子情報通信学会信越支部大会  2007.9 

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  • 能動騒音制御におけるオンライン推定法の研究

    山崎瞬, 菊池久和, 村松正吾

    電子情報通信学会信越支部大会  2007.9 

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  • Particleフィルタを用いた水面追跡 (メディア工学)

    小林 信介, 村松 正吾, 菊池 久和

    映像情報メディア学会技術報告  2007.8 

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  • Nonseparable DWT based on Lattice Structure for Video Coding

    ADACHI Atsuyuki, HIKI Minoru, MURAMATSU Shogo, KIKUCHI Hisakazu

    Proceedings of the Annual Conference of the Institute of Image Electronics Engineers of Japan  2007.8 

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    In this work, a new design method of linear-phase orthogonal nonseparable discrete wavelet transforms (DWT) with 2 vanishing moments are proposed based on lattice structure as a new tool for video coding. The DWTs used in JPEG2000 are known to yield fluctuation of hazy distortion when applied to motion picture. Our conjecture is that the DWTs do not have the orthogonal property. Since our proposed DWT has the orthogonal property, it is possible to reduce the hazy distortion. Coding experiments for real videos are shown for evaluating the relation between the spatial correlation of the distortion in the reconstructed picture and the orthogonal property of the transform.

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  • Gaussian Mixture Model for River Region Classification

    OHKURA Makoto, MURAMATSU Shogo, KIKUCHI Hisakazu, IWAHASHI Masahiro

    Reports of the Technical Conference of the Institute of Image Electronics Engineers of Japan  2007.8 

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    This report proposes a river region classification using a Gaussian mixture model for feature vectors. The conventional method classifies river region by assuming a single Gaussian distribution. Since this work assumes a Gaussian mixture distribution, better classification performance can be expected because it becomes possible to approximate more complex distributions than any single Gaussian. Experimental results with real surveillance videos are shown for evaluating the performance of the proposed method, and improvement of the performance from the conventional method in term of precision is verified.

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  • 定色相原理を用いた補間方向推定によるカラーデモゼイシング (メディア工学)

    大野 寛仁, 高橋 善寿, 菊池 久和, 村松 正吾

    映像情報メディア学会技術報告  2007.8 

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  • An Application of Fuzzy Reasoning to Image Object Extraction and Recognition

    MIYAGUCHI Tatsuya, TAKAHASHI Yoshihisa, KIKUCHI Hisakazu, MURAMATSU Shogo, KOBAYASHI Jyunichi

    IEICE technical report  2007.7 

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    Fuzzy reasoning is a method to make machines reason by themselves. Fuzzy reasoning gives the degree of likelihood for which an element in issue belongs to the set, whereas the ordinary set theory gives one of two states whether the element belongs to the set. This is referred to as fuzzification. The reasoning is done in accordance with the fuzzy rules denned with the fuzzified values in advance. The output is the defuzzified value of the reasoning result. Becouse of these reasoning processes, fuzzy reasoning is accepted as an easy and effective method for the expression of the human empirical knowledge. This paper proposes a system that makes extraction and classification of objects in an image. The system consists of a preprocessing, feature extraction and classification processes with fuzzy reasoning.

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  • Reduction in Perceptual Distortion for Wavelet Transform-Based Video Decoding

    MURATA Yutaka, KIKUCHI Hisakazu, MURAMATSU Shogo

    IEICE technical report  2007.7 

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    Motion JPEG2000 is a video coding system on the basis of wavelet transforms. It has many advantages such as easy editing, unified lossless/lossy compression, resolution and SNR scalabilities. However, there can produce some noise referred to as "flicker artifacts". Since it is visually annoying in a video sequence, it is strongly desirable to reduce it for quality decoding. In this paper, a distortion reduction method at a decoder is presented. The distortion is differentiated from the sequence movement by the region mean of frame difference. The information of previous frames is used to improve the perceptual appearance of the current frame. Experimental results demonstrate that the proposed method works well.

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  • Orthogonality of DWTs and Correlation of Distortion in Video Coding

    ADACHI Atsuyuki, HIKI Minoru, MURAMATSU Shogo, KIKUCH Hisakazu

    IEICE technical report  2007.7 

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    In this work, we evaluate the relation between the spatial correlation of the distortion in the reconstructecd picture and the orthogonality of DWTs in video coding. The DWTs used in JPEG2000 are known to yield fluctuation of hazy distortion when applied to motion picutres. Our conjecture is that the orthogonal property affects the artifacts. Simulation and coding experiments for real videos are shown for evaluating the relation between the spatial correlation of the distortion in the reconstructed picture and the orthogonal property of the transform.

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  • Spatio-temporal Filtering with Motion/Edge-based Prediction for Video Coding

    HIKI Minoru, MURAMATSU Shogo, KIKUCHI Hisakazu

    IEICE technical report  2007.7 

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    This work studies spatio-temporal filtering with motion/edge-based prediction for video coding, which is an alternative technique of non-separable motion-compensated spatio-temporal filtering (MCSTF). The proposed technique replaces motion compensation of MCSTF with edge-based prediction, and has an advantage in computational efficiency without motion-compensation. The proposed technique is based on the lifting scheme so that perfect reconstruction property is guaranteed. Some experimental results with JPEG2000 show the significance of our proposed technique.

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  • Perceptual Distortion Reduction in Wavelet Transform-Based Video Decoding

    MURATA Yutaka, KIKUCHI Hisakazu, MURAMATSU Shogo

    IEICE technical report  2007.6 

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    Motion JPEG2000 is a video coding system on the basis of wavelet transforms. It has many advantages such as easy editing, unified lossless/lossy compression, resolution and SNR scalabilities. However, there can produce some noise refered to as "flicker artifacts". We need to reduce it because it is visually annoying in a video sequence. In this paper, a distortion reduction method at a decoder is studied. The distortion is differentiaded from the sequence movement by the region mean of frame difference. The information of previous frames is used to improve the perceptual appearance of the current frame. Experimental results demonstrate that the proposed method works well.

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  • 映像符号化のための多次元非分離DWT

    安達充幸, 比企豊, 村松正吾, 菊池久和

    画像電子学会年次大会  2007.5 

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  • Linear-phase orthogonal nonseparable wavelet transforms for video coding and correlation of the distortion

    安達 充幸, 比企 豊, 村松 正吾

    回路とシステム軽井沢ワークショップ論文集  2007.4 

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  • Parallel computation of EM algorithm on a cell processor

    二田 晴彦, 村松 正吾, 菊池 久和

    回路とシステム軽井沢ワークショップ論文集  2007.4 

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  • Color demosaicing using asymmetric average interpolation and hue-transition smoothing

    高橋 善寿, 開 健太朗, 菊池 久和, 村松 正吾

    回路とシステム軽井沢ワークショップ論文集  2007.4 

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  • Functionally layered coding for river surveillance

    高橋 知将, 今井 裕二, 岩橋 政宏, 村松 正吾

    回路とシステム軽井沢ワークショップ  2007.4 

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  • Spatio-temporal Filtering with Edge-based Prediction for Video Coding

    HIKI Minoru, MURAMATSU Shogo, KIKUCHI Hisakazu

    IEICE technical report  2007.4 

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    This work studies spatio-temporal filtering with edge-based prediction for video coding, which is an alternative technique of non-separable motion-compensated spatio-temporal filtering (MCSTF). The proposed technique replaces motion-compensation of MCSTF with edge-based prediction, and has advantage in computational efficiency without motion-compensation. The proposed technique is based on the lifting scheme so that perfect reconstruction property is guaranteed. Some experimental results with JPEG2000 show the significance of our proposed technique.

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  • A-4-3 A Float-Point RTL Model of EM Algorithm for Gaussian Mixtures

    Watanabe Tsutomu, Muramatsu Shogo, Kikuchi Hisakazu

    Proceedings of the IEICE General Conference  2007.3 

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  • Real Time Analysis on Dynamic Periodontal Bacteria Image Using Digital Signal Processor

    KAMIMURA Masahiro, KIKUCHI Hisakazu, MURAMATSU Shogo

    ITE technical report  2006.12 

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  • Condensationアルゴリズムを用いた河川水面追跡

    小林信介, 村松正吾, 菊池久和, 岩橋政宏

    映像メディア処理シンポジウム(IMPS)  2006.11 

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  • EMアルゴリズムを用いた混合正規分布推定器のLSIアーキテクチャ

    本多秀章, 村松正吾, 菊池久和

    第21回信号処理シンポジウム  2006.11 

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  • 色相値の復元を利用したカラーデモゼイシングの検討

    開 健太朗, 高橋 善寿, 菊池 久和, 村松 正吾

    第21回画像符号化シンポジウム(PCSJ)  2006.11 

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  • EMアルゴリズムを用いた混合正規分布推定モジュールのLSIアーキテクチャ

    本多秀章, 村松正吾, 菊池久和

    第11回映像メディア処理シンポジウム  2006.11 

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  • EMアルゴリズムを用いた混合正規分布推定ハードウェアの実装

    本多秀章, 村松正吾, 菊池久和

    電子情報通信学会信越支部大会  2006.9 

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  • River State Classification with Dynamic Texture Analysis

    HIKI Minoru, MURAMATSU Shogo, KIKUCHI Hisakazu, IWAHASHI Masahiro

    ITE technical report  2006.8 

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  • Line Tracking with Condensation Algorithm and its Application to River Image Analysis

    KOBAYASHI Shinsuke, MURAMATSU Shogo, KIKUCHI Hisakazu, IWAHASHI Masahiro

    ITE technical report  2006.8 

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  • Visual Artifact Reduction Observed in Lower-Bitrate Video Encoded by Wavelet-Based Coding

    IIDA Takayuki, KIKUCHI Hisakazu, MURAMATSU Shogo

    IEICE technical report  2006.7 

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    Wavelet transform-based coding, like JPEG 2000, has various features such as high coding performance, unified lossless/lossy compression, resolution and SNR scalabilities. However, some visual artifacts produced by quantization appear in lower-bitrate video encoded by wavelet-based coding. It is indispensable to reduce visual artifacts with a flicker because they are visually noticeable. In this paper, we study the method of a spatio-temporal error diffusion to reduce the visual artifacts in video. The error is defined by a difference between an original frame and a decoded frame after quantization and it is diffused to the next frame to improve image quality. We show the validity of the proposed method by experiments.

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  • Motion-Compensated Spatio-Temporal Filtering with Reference-Type Variable-Coefficient Invertible Deinterlacer

    OKADA Toshiyuki, MURAMATSU Shogo, HIKI Minoru, KIKUCHI Hisakazu

    ITE technical report  2006.6 

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  • Performance Evaluation of Motion-Compensated Spatio-Temporal Filtering with Spatial DWT

    Minoru Hiki, Takuma Ishida, Shogo Muramatsu, Hisakazu Kikuch

    第19回回路とシステム軽井沢ワークショップ  2006.4 

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  • D-11-6 A Study on Lossless Image Compression by Embedded Coding

    Shinoda Kazuma, Kikuchi Hisakazu, Muramatsu Shogo

    Proceedings of the IEICE General Conference  2006.3 

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  • On Sub-sampling Lattices for Motion-Compensated Spatiotemporal Filtering (MCSTF)

    MURAMATSU Shogo, HIKI Minoru, ISHIDA Takuma, KIKUCHI Hisakazu

    ITE technical report  2005.12 

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  • On Bayesian Networks and Features for Player Face Detection in Soccer Videos

    TAKASHIMA Hiroaki, MURAMATSU Shogo, KIKUCHI Hisakazu

    ITE technical report  2005.12 

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  • Automatic setting of the threshold for Detecting Video Shot Boundaries in Wavelet Transform Domain

    NOMOTO Atsunori, HASEBE Satosi, MURAMATU Shogo, KIKUCHI Hisakazu

    ITE technical report  2005.12 

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  • Color Demosaicing Using Edge Directed Interpolation and Hue-Gradient Smoothing

    HIRAKI Kentaro, TAKAHASHI Yoshihisa, KIKUCHI Hisakazu, MURAMATSU Shogo

    ITE technical report  2005.12 

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  • 非対称算術平均補間によるカラーデモゼイシング

    高橋 善寿, 開 健太朗, 菊池 久和, 村松 正吾, 水谷 直喜

    第20回信号処理シンポジウム  2005.11 

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  • 非可逆符号化を用いた可逆画像符号化法の検討

    篠田一馬, 村松正吾, 菊池久和

    画像符号化シンポジウム(PCSJ)  2005.11 

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  • フィールド・スケーラブル映像符号化のための非分離MCTFの基礎検討

    比企豊, 石田拓麿, 村松正吾, 菊池久和

    画像符号化シンポジウム(PCSJ)  2005.11 

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  • EMアルゴリズムによる混合正規分布推定のためのCORDICを用いた隠れ変数事後確率計算モジュール

    小池和博, 村松正吾, 菊池久和

    電気関係学会北陸支部連合大会  2005.9 

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  • Hierarchical Variable-Coefficient Deinterlacer Banks for Scalable Video Coding

    ISHIDA Takuma, MURAMATSU Shogo, HIKI Minoru, KIKUCHI Hisakazu

    ITE technical report  2005.6 

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  • Dynamic Shape Description with CSS(Curvature Scale Space) for Video Retrieval

    KOBAYASHI Shinsuke, MURAMATSU Shogo, KIKUCHI Hisakazu

    Proceedings of the Annual Conference of the Institute of Image Electronics Engineers of Japan  2005.6 

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    Requirements of effective video retrieval is growing because of increase of video content distribution services. Therefore, in this report, we propose a feature descriptor that describe an object contour and its transformation. This descriptor is based on CSS(Curvature Scale Space) which is the shape descriptor defined in MPEG-7.

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  • 階層型動き補償デインタレーサバンクを用いた時空間多重解像度解析

    比企 豊, 石田 拓麿, 北川 大輔, 村松 正吾, 菊池 久和

    第18会回路とシステム軽井沢ワークショップ  2005.4 

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  • 可変係数デインタレーサバンクのための相互参照型パラメータ決定法

    村松正吾, 石田拓麿, 打田淳, 渡辺裕樹, 菊池久和

    第18回回路とシステム軽井沢ワークショップ  2005.4 

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  • Hardware Architecture of Point-based Deinterlacers

    MATSUNAGA Yoshinori, MURAMATSU Shogo, KIKUCHI Hisakazu

    Proceedings of the Annual Conference of the Institute of Image Electronics Engineers of Japan  2005 

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    Recent developments of the telecommunication infrastructures brought us many ways of visual communication. Thus, scalable video coding that can handle various formats on demand is required. In our laboratory, we have proposed deinterlacer banks with the perfect reconstruction property as a new tool of spatio-temporal scalable video coding. This work further proposes an architecture of an invertible deinterlacer, a component of deinterlacer banks, based on Face-Centered-Orthorhombic (FCO) sampling. The perfect reconstruction property is simulated through its VHDL model in order to verify the specification of the functionality. Then the performance is also evaluated through the synthesis results.

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  • ROI Extraction in Soccer Video Sequences

    TAKASHIMA Hiroaki, MURAMATU Shogo, KOBAYASHI Shinsuke, KIKUCHI Hisakazu

    Proceedings of the Annual Conference of the Institute of Image Electronics Engineers of Japan  2005 

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    In this work, we propose an automatic ROI extraction method with Bayesian networks .We apply a the Bayesian network to semantic transcoding by taking into account ROI in spatial domain. In our experiments, we use football sequences because of easyness of modeling probabilistic structure in scenes of video sequences. We evaluate the performance of our ROI extraction method by setting faces of football players as ROI. Several experiments showed that the proposed method can achieve high recall and precision rate and can extract football players faces only excluded other faces automatically.

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  • 動的に構築されるストーリーボードを用いた動画像閲覧

    長谷部聡, 村松正吾, 菊池久和

    映像メディア処理シンポジウム(IMPS)  2004.11 

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  • 非対称空間平均と反復によるデモゼイシングの提案

    高橋善寿, 菊池久和, 村松正吾, 阿部淑人, 水谷直喜

    第19回信号処理シンポジウム  2004.11 

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  • 時空間スケーラブル映像符号化のための階層型デインタレーサバンク

    石田拓麿, 村松正吾, 打田淳, 北川大輔, 菊池久和

    画像符号化シンポジウム(PCSJ)  2004.11 

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  • ストリーミングを考慮した品質主導型動画像符号化の検討

    角玄 涼, 水谷直喜, 長谷部聡, 村松正吾, 菊池久和

    電子情報通信学会信越支部大会  2004.10 

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  • 能動騒音制御システムのC6713DSKへの実装

    染谷秀明, 佐藤元樹, 村松正吾, 菊池久和

    第6回DSPS教育者会議  2004.10 

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  • 時空間ウェーブレット変換による動的テクスチャ解析とその応用

    今野裕也, 村松正吾, 佐々木重信, 周杰, 菊池久和

    電子情報通信学会信越支部大会  2004.10 

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  • DSPを用いた歯周病菌映像のリアルタイム解析

    金子昌弘, 長谷部聡, 村松正吾, 菊池久和, 角田勇

    電子情報通信学会信越支部大会  2004.10 

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  • JPEG2000係数ビットモデリング部のハードウェア実装に関する一検討

    緑川健志, 村松正吾, 周杰, 佐々木重信, 菊池久和

    電子情報通信学会信越支部大会  2004.10 

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  • ドットフォーミングハーフトーンの提案

    斎藤一幸, 菊池久和, 村松正吾, 阿部淑人

    日本画像学会年次大会  2004.6 

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  • フィールドスケーラブル映像符号化のための完全再構成デインタレーサバンク

    石田拓麿, 村松正吾, 北川大輔, 小林信介, 菊池久和

    第17回回路とシステム軽井沢ワークショップ  2004.4 

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  • ウェーブレット係数のクラスタリングによるキーフレーム選択

    長谷部聡, 南雲真, 村松正吾, 菊池久和

    第17回回路とシステム軽井沢ワークショップ  2004.4 

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  • D-11-11 Maximally-Decimated Perfect Reconstruction Deinterlacer Banks Based on FCO Sampling

    KITAGAWA Daisuke, ISHIDA Takuma, MURAMATSU Shogo, KIKUCHI Hisakazu

    Proceedings of the IEICE General Conference  2004.3 

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  • On Rake Reception of Ultra Wideband (UWB) Signal over Dense Multipath Channels for various Pulse-widths

    M. A. Rahman, S. Sasaki, J. Zhou, S. Muramatsu, H. Kikuchi

    電子情報通信学会ワイドバンドシステム研究会  2004.3 

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  • On Rake Reception of Ultra Wideband (UWB) Signals Over Dense Multipath Channels for Various Pulse-widths

    RAHMAN Mohammad Azizur, SASAKI Shigenobu, ZHOU Jie, MURAMATSU Shogo, KIKUCHI Hisakazu

    IEICE technical report. WBS, Wideband System  2004.2 

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    In this paper we present extensive simulation results on various Rake reception of ultra wideband (UWB) signals over IEEE 802.15.3a realistic UWB channel models using BPSK modulation. Convolving the continuous time impulse response with the transmitted pulse and adding WON, we produce the multipath profile in front of the receiver. We show that the more the pulse-width gets shorter, the more fraction of the energy comes to the receiver through isolated paths. Oppositely, the wider is the pulse, the more fraction of the energy is in overlapped path and the more is the multipath fade. We show performance of all Rake (ARake) and selective Rake (SRake) receivers by optimal delay estimation and by ordinary method. We observe wide performance variations in the two methods. We also show an optimum pulse-width for an SRake receiver for each channel model (CM1〜CM3).

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  • Hardware Implementation of Invertible Deinterlacing with Horizontal Decimation of Coefficient Parameters

    SOYAMA Tatsuumi, UCHITA Jun, ISHIDA Takuma, MURAMATSU Shogo, KIKUCHI Hisakazu, KUGE Tetsuro

    IEICE technical report. Circuits and systems  2004.1 

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    In this report, an architecture of invertible deinterlacing with horizontal decimation of coefficient-parameter is proposed. Invertible deinterlacing can be used for interlaced video as preprocessing of frame-based motion picture codec, such as Motion-JPEG2000 (MJP2). When simple field-interleaving is used, comb-tooth artifacts may appear around edges of motion objects. In contrast, invertible deinterlacing technique can suppress comb-tooth artifacts and also guaranties original picture recovery on demand. In previous work, we have developed a variable coefficient scheme with a motion detection filter, which realizes adaptability to local characteristics of pictures. When the scheme is applied to an image codec, it is necessary to send the coefficient parameters to receivers to recover the original image. Before we have shown that the coefficient parameters can be reduced by horizontally decimating while maintaining the comb-tooth suppression ability. This report shows that an architecture of our proposed parameter decimation approach, of which performance is also evaluated by using VHDL models.

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  • Parameter Embedding Method of Variable-Coefficient Invertible Deinterlacer into ROI in Motion-JPEG2000

    UCHITA Jun, SOYAMA Tatsuumi, ISHIDA Takuma, MURAMATSU Shogo, KIKUCHI Hisakazu, KUGE Tetsuro

    IEICE technical report. Circuits and systems  2004.1 

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    In this report, a coefficient-parameter embedding method is proposed for invertible deinterlacing with variable coefficients in the application to Motion-JPEG2000 (MJP2). Invertible deinterlacing, which the authors have developed before, can be used as a preprocess of frame-based motion picture codec, such as MJP2, for interlaced videos. When the conventional field-interleaving is used instead, comb-tooth artifacts appear around edges of moving objects. On the other hand, the invertible deinterlacing technique allows us to suppress the comb-tooth artifacts and also to recover an original picture on demand. As previous works, the authors have developed a variable coefficient scheme with a motion detector, which realizes adaptability to local characteristics of given pictures. When applying this deinterlacing technique to an image codec, however, it is required to send coefficient parameters to receivers for original picture recovery. This work proposes a parameter-embedding technique and constructs a standard stream which consists both of picture data and parameters. We investigate to embed the parameters into the LH_1 component of the wavelet domain through the ROI (region of interest) function of JPEG2000 without significant loss in the performance of comb-tooth supression.

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  • 内容型動画像検索を考慮したウェーブレット変換領域におけるショット境界検出

    長谷部聡, 南雲真, 村松正吾, 周杰, 佐々木重信, 菊池久和

    第18回デジタル信号処理シンポジウム  2003.11 

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  • Effects of Partial Band Jamming on the Performance of Generalized Selection Combining Rake Receiver in Direct Sequence Spread Spectrum(DS-SS) Communications

    RAHMAN Mohammad Azizur, SASAKI Shigenobu, ZHOU Jie, MURAMATSU Shogo, KIKUCHI Hisakazu

    IEICE technical report. WBS, Wideband System  2003.10 

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    Effects of partial band jamming on the performance of generalized selection combining (GSC) Rake receiver in direct sequence spread spectrum (DS-SS) communications have been investigated. Especially, we focus on effects of jamming on optimum spreading bandwidth for a fixed complexity GSC Rake receiver. The received signals are considered to undergo multipath fading over an independently and identically distributed (i.i.d.) Rayleigh channel, Expressions for performance measure at jamming environment have been derived as a function of system parameters and signal to jamming power ratio (P/J). A flat power delay profile (PDP) is considered for DS-SS. The idea is extended to direct sequence ultra wideband (DS-UWB) communications considering an exponentially decaying PDP. A fixed complexity GSC receiver designed to perform optimally for a given system bandwidth by outputting minimum achievable BEP, is found to perform sub-optimally in presence of jamming in both cases. However, effects of jamming are much less pronounced in case of a decaying PDP.

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  • 歯周病菌映像からの菌体抽出と追跡および活性度評価

    大場正也, 長谷部聡, 金子昌弘, 村松正吾, 菊池久和, 東福寺幾夫

    電子情報通信学会信越支部大会  2003.10 

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  • Impact of Narrowband Interference and Timing Jitter for Multiphase DS-UWB Signals

    Kusama Takumi, Sasaki Shigenobu, Zhou Jie, Muramatsu Shogo, kikuchi Hisakazu

    Proceedings of the Society Conference of IEICE  2003.9 

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  • A lossless implementation of invertible deinterlacing for Motion-JPEG2000

    Ishida Takuma, Muramatsu Shogo, Zhou Jie, Sasaki Shigenobu, Kikuchi Hisakazu

    Proceedings of the Society Conference of IEICE  2003.9 

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  • Extraction of MPEG-7 Color Layout Discriptor from JPEG2000 Pictures

    Iwafuchi Toshihiro, Muramatsu Shogo, Zhou Jie, Sasaki Shigenobu, Kikuchi Hisakazu

    Proceedings of the Society Conference of IEICE  2003.9 

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  • Iterative Demodulation / Decoding for Coded Differential Parallel Combinatorial Spread Spectrum Systems

    Sasaki Shigenobu, Asakawa Masashi, Hafuka Takamitsu, Zhou Jie, Muramatsu Shogo, Kikuchi Hisakazu

    Proceedings of the Society Conference of IEICE  2003.9 

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  • Generalized Equations for Spatial Correlation of a Circular Antenna Array

    ISHIZAWA Kenta, ZHOU Jie, SASAKI Shigenobu, MURAMATSU Shogo, KIKUCHI Hisakazu

    Proceedings of the Society Conference of IEICE  2003.9 

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  • Two-Step Algorithm for Detecting Video Shot Boundaries in a Wavelet Transform Domain

    HASEBE Satoshi, MURAMATSU Shogo, ZHOU Jie, SASAKI Shigenobu, KIKUCHI Hisakazu

    ITE technical report  2003.6 

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  • Evaluation of Filters in Invertible Deinterlacing for Motion-JPEG2000

    ISHIDA Takuma, MURAMATSU Shogo, JIE ZHOU, SASAKI Shigenobu, KIKUCHI Hisakazu

    ITE technical report  2003.6 

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  • Impact of Narrowband Interference and Timing Jitter in DS-UWB System

    SASAKI Shigenobu, KUSAMA Takumi, ZHOU Jie, MURAMATSU Shogo, KIKUCHI Hisakazu

    IEICE technical report. WBS, Wideband System  2003.5 

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    Ultra-wideband (UWB) is a new wireless communications technology using very short pulses less than a few nano-seconds. Transmitting signal usually occupies several giga-hertz bandwidth. In UWB communications, timing jitter at pulse generators causes the performance degradation. Narrowband interference (NBI) from conventional wireless communication entities is also a major degrading factor for error-rate performances in UWB systems. In this paper, we investigated impact of timing jitter and NBI in UWB system employing direct sequence spread spectrum (DS/SS) modulation. Gaussian monocycle pulse and modulated gaussian pulse is considered as the pulse waveforms. Simulation results show that root-mean-square (RMS) jitter should be less than a few percent of pulse width in order to maintain the ideal error-rate performance. If signal to interference ratio (SIR) becomes less than 20 dB,error rate performance is getting worse, especially modulated gaussian pulse is employed.

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  • Coefficient-Parameter Reduction of Invertible Deinterlacing with Variable Coefficients by Horizontal Decimation

    MURAMATSU S, UCHITA J, ISHIDA T, KIKUCHI H, KUGE T

    Technical report of IEICE. DSP  2003.3 

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    ln this report, a coefficient-parameter-reduction method is proposed for invertible deinterlacing with variable coefficients. Invertible deinterlacing, which the authors have developed, can be used for interlaced video as preprocessing of frame-based motion picture codec, such as Motion-JPEG2000(MJP2). When simple conventional field-interleaving is used, comb-tooth artifacts may appear around edges of motion objects. 0n the other hand, the invertible deiliterlacing technique allows us to suppress comb-tooth artifacts and also to restore an original picture on demand. As previous works, the authors have developed a variable coefficient scheme with a motion detection filter, which realizes adaptability to local characteristics of pictures. When applying this deinterlacing technique to an image codec. It is necessary to send coefficient parameters to receivers for original picture recovery. This report shows that these coefficient parameters can be reduced by decimating horizontally without significant loss of comb-tooth suppression ability.

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  • A method of video shot boundary detection on a wavelet-transformed domain

    Nagumo Makoto, Hasebe Satoshi, Muramatsu Shogo, Zhou Jie, Sasaki Shigenobu, Kikuchi Hisakazu

    Proceedings of the IEICE General Conference  2003.3 

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  • マルチレート・マルチユーザ環境におけるDS/CDMAパケットセルラーシステムの性能評価

    石澤賢太, 周杰, 佐々木重信, 村松正吾, 菊池久和

    電子情報通信学会総合大会  2003.3 

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  • M-ary TH/CSK Systems for Ultra Wideband (UWB) Wireless Communications

    SASAKI Shigenobu, SUZUKI Tomohiko, ZHOU Jie, MURAMATSU Shogo, KIKUCHI Hisakazu

    Technical report of IEICE. SST  2002.6 

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    In this paper, we propose a M-ary time-hopping/code shift keying (M-ary Th/CSK) modulation for ultra-wideband (UWB) wireless communications. UWB transmission is a promising technology in the future high-rate wireless personal area network (WPAN). Since very short pulse is used in UWB system, transmitting signal occupies extremely wide bandwidth. In the proposed M-ary TH/CSK system, an element of time-hopped sequence is used for choosing a transmitting code sequence among pre-assigned codes. A set of optical orthogonal code and its cyclic shift is used as a set of pre-assigned codes. Transmitter and receiver configurations of M-ary TH/CSK system are described. Preliminary result of error rate performance is also displayed under AWGN environment.

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  • Invertible Deinterlacing with Variable Coefficients

    MURAMATSU Shogo, ISHIDA Takuma, KIKUCHI Hisakazu, KUGE Tetsuro

    Technical report of IEICE. DSP  2002.6 

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    In this work, invertible deinterlacing with variable coefficients is proposed. As previous works, we have developed invertible deinterlacing that suppresses comb-shaped artifacts caused by field-interleaving for interlaced scanning video, which affect the quality of low-bitrate intraframe-based codec such as Motion-JPEG2000. However, since the coefficients of the deinterlacing filters are fixed it is not necessarily optimal for local characteristics of given pictures. To improve local adaptability, we propose to introduce variable coefficients so that filters can be changed according to local properties of pictures, while keeping the invertibility. The performance of our proposed method is evaluated by showing the effect as a deinteralcing prefilter, and also the coding efficiency of a whole system in which our proposed method is embeded.

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  • M-ary TH/CSK Systems for Ultra Wideband (UWB) Wireless Communications

    SASAKI Shigenobu, SUZUKI Tomohiko, ZHOU Jie, MURAMATSU Shogo, KIKUCHI Hisakazu

    Technical report of IEICE. SAT  2002.6 

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    In this paper, we propose a M-ary time-hopping/code shift keying (M-ary TH/CSK) modulation for ultra-wideband (UWB) wireless communications. UWB transmission is a promising technology in the future highrate wireless personal area network (WPAN). Since very short pulse is used in UWB system, transmitting signal occupies extremely wide bandwidth. Inthe proposed M-ary TH/CSK system, an element of time-hopped sequence is used for choosing a transmitting code sequence among pre-assigned codes. A set of optical orthogonal code and its cyclic shift is used as a set of pre-assigned codes. Transmitter and receiver configurations of M-ary TH/CSK system are described. Preliminary result of error rate performance is also displayed under AWGN environment.

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  • Finer-Scale Pseudo Gray for an sRGB CRT Monitor

    KIKUCHI Hisakazu, SATO Hiroto, HASEBE Satoshi, MIZUTANI Naoki, MURAMATSU Shogo, SASAKI Shigenobu, ZHOU Jie, SEKINE Seishi, ABE Yoshito, NAKASHIZUKA Makoto

    Technical report of IEICE. DSP  2002.5 

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    Fine grayscale data, which exceed eight bits per pixel, are mapped onto points around the achromatic axis in the 8-bit sRGB color space so as to be displayed on an 8-bit sRGB CRT monitor. The characteristics of the pseudo gray are investigated in terms of the CIELAB color difference and a^*b^* coordinates.

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  • 完全再構成デ・インタレース化処理のリフティング実装

    曽山 竜海, 石田 拓麿, 村松 正吾, 菊池 久和, 久下 哲郎

    第15回回路とシステム(軽井沢)ワークショップ  2002.4 

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  • 3-Dimensional Significance Descriptor for Content-Based Video Retrieval

    村松 正吾谷部聡, 村松正吾, 佐々木重信, 菊池久和

    第15回回路とシステム(軽井沢)ワークショップ  2002.4 

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  • Efficient Estimation Scheme of Channel State Information for Parallel Combinatorial SS Sytems(2)

    Takizawa Kenichi, Sasaki Shigenobu, Zhou Jie, Muramatsu Shogo, Kikuhchi Hisakazu

    Proceedings of the IEICE General Conference  2002.3 

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  • Forward Link Capacity of a CDMA Cellular System with Mixed Cell Sizes

    H.Zhao, H.Kikuchi, J.Zhou, S.Sasaki, S.Muramatsu

    電子情報通信学会総合大会  2002.3 

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  • Performance Investigation of Diversity Reception with Perfect/Imperfect Channel Evaluation

    J.Zhou, H.Kikuchi, S.Sasaki, S.Muramatsu

    電子情報通信学会総合大会  2002.3 

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  • Iterative demodulation/decoding for multiphase parallel combinatorial spread spectrum systems

    HAFUKA Takamitsu, SASAKI Shigenobu, TAKIZAWA Ken-ichi, ZHOU Jie, MURAMATSU Shogo, KIKUCHI Hisakazu

    情報理論とその応用シンポジウム予稿集 = The proceedings of the Symposium on Information Theory and Its Applications  2001.12 

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  • Intra-Frame/Field-Based Motion Picture Coding with Perfect Reconstruction De-interlacing

    ISHIDA T, MURAMATSU S, Z. JIE, SASAKI S, KIKUCHI H

    IEICE technical report. Circuits and systems  2001.11 

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    In this work, we consider applying perfect reconstruction de-interlaing to intra-frame/field-based codec system so that the system structure can realize a rich scalability with one bit stream according to requirements for image quality. When the conventional field interleaving or separation is applied for an interlaced picture, the intra-frame/field-based codec system causes horizontal comb-shape artifacts at edges of motion part or aliasing. Due to these effects, the low-bitrate-decoded pictures are degraded around the edges. The proposed technique is shown that the pictures decoded on low bitrate causes less comb-shape artifacts except for extra-process and the one decoded on high bitrate are able to be kept the spacial-resolution. It is also shown that the efficient implementation and lossless implementation exist for a unique case.

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  • 空間-時間ブロック符号化並列組合せSS方式に関する一検討

    村松 正吾早川, 佐々木, 周, 村松, 菊池

    電子情報通信学会信越支部大会  2001.10 

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  • Repeat-Accumulate符号を用いたDS/SS通信システムの検討

    吉野, 佐々木, 周, 村松, 菊池

    電子情報通信学会信越支部大会  2001.10 

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  • Spectrum Sharing System of TDMA/W-CDMA with Interference Cancellation

    Jie Zhou, H.Kikuchi, S.Sasaki, S.Muramatsu

    電子情報通信学会信越支部大会  2001.10 

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  • BER Performance Evaluation of a CDMA Cellular System with a Combination of Tilted Antenna Arrays and Power Control

    Jie Zhou, H.Kikuchi, S.Sasaki, S.Muramatsu, Y.Onozato

    電子情報通信学会ソサイエティ大会  2001.9 

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  • Separate FEC Coding for Parallel Combinatorial SS Systems

    Harada Tomoyuki, Sasaki Shigenobu, Kikuchi Hisakazu, Muramatsu Shogo, Jie Zhou

    Proceedings of the Society Conference of IEICE  2001.8 

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  • An Approach to Fast Content-based Video Querying Based on a Wavelet Decomposition

    Hasebe Satoshi, Muramatsu Shogo, Sasaki Shigenobu, Jie Zhou, Kikuchi Hisakazu

    Proceedings of the Society Conference of IEICE  2001.8 

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  • Efficient Estimation Scheme of Channel State Information for PC/SS Systems

    Takizawa Ken-ichi, Sasaki Shigenobu, Zhou Jie, Muramatsu Shogo, Kikuchi Hisakazu

    Proceedings of the Society Conference of IEICE  2001.8 

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  • Performance Evaluations for Block Coded Parallel Combinatorial Spread Spectrum Systems with Iterative Demodulation/Decoding

    TAKIZAWA Kenichi, SASAKI Shigenobu, ZHOU Jie, MURAMATSU Shogo, KIKUCHI Hisakazu

    Technical report of IEICE. DSP  2001.7 

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    We dcrive the upper bound of the bit crror rate for block coded parallcl combinatorial spread spectrum(PC/SS)systems with an itcrative demodulation/decoding. In this paper, the suitable selecting mcthod for the constant weight code has been discussed by using the dcrived upper bound. The result is that constant weight codes made from a Hadamard matrix are superior to Shalkwijk's constant weight codes on the block coded PC/SS systems with iterative demodulation/decoding from the viewpoint of the asympotic error rate. We have also compared the bit error rate performances of Reed-Solomon codcd systems with the performances of proposed demodulation/decoding systems. Bit error performance in the proposed systems are superior to that in Reed Solomon coded systems in the term of the required signal to noise ratio per bit for satisfying 10^-6 BER.

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  • パケット伝送における階層的誤り制御を組み合わせたゼロツリー 画像符号化法

    佐々木, 菊池, 村松

    第3回YRP移動体通信産学官交流シンポジウム  2001.7 

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  • A Bit-Operation-Based Algorithm of Dominant Color Extraction

    KURIHARA Tomotaka, MURAMATSU Shogo, SASAKI Sigenobu, KIKUCHI Hisakazu

    Proceedings of the IEICE General Conference  2001.3 

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  • Multistage Forward Error Correction for Wavelet Zerotree Image Coding in Packet Transmission

    SHIRAI Michitomo, SASAKI Shigenobu, MURAMATSU Shogo, JOO Sang-hyun, KIKUCHI Hisakazu

    IEICE technical report. Circuits and systems  2001.1 

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    In this paper, a hybrid method of wavelet zerotree image coding and forward error correction(FEC)by using product code is proposed for packet transmission.A modified packetization scheme for wavelet zerotree image coding is proposed to localize the impact of packet loss and bit errors.FEC coding by using Reed-Solomon product code is applied to protect image data from packet loss and bit errors.Computer simulation based on ATM(asynchronous transfer mode)network is performed.Results shows that the proposed method effectively works to protect compressed image data from packet loss and channel bit errors.

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  • ウェーブレット変換領域における動き推定(信号処理シンポジウム)

    大塚, 山田, 菊池, 朱, 村松

    第15回デジタル信号処理シンポジウム  2000.11 

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  • 無遅延サブバンド適応フィルタによる騒音制御について

    伊藤,村松, 菊池, 佐々木, 冨澤

    電気学会東京支部新潟支所研究発表会  2000.11 

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  • カーディナルスプライン補間を用いた画像加工に適した輪郭抽出表現についての検討

    鈴木,中静, 菊池,村松

    電気学会東京支部新潟支所研究発表会  2000.11 

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  • 医療画像の蓄積と伝送に関する研究

    佐藤,水谷,菊池, 佐々木,朱, 村松, 内藤,酒井

    電気学会東京支部新潟支所研究発表会  2000.11 

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  • ウェーブレット変換領域における動き推定(画像符号化シンポジウム)

    山田, 菊池, 佐々木, 朱, 村松

    画像符号化シンポジウム (PCSJ)  2000.11 

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  • Memory Access Estimation of Filter Bank Implementation on Different DSP Architectures

    MIZUTANI Naoki, MURAMATSU Shogo, KIKUCHI Hisakazu

    Technical report of IEICE. DSP  2000.10 

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    In this report, supposing digital signal processors (DSP) of different architectures, the efficient implementation of filter banks is investigated. Especially, focusing on the memory accesses, the number of memory transfers, the power consumptions and the processing accuracies are discussed. DSP 〓mploys the Harvard architecture for fast signal processing and has special functional units, such as multiplier-and-accumulator (MAC) units, Barrel shifters and so forth. Even if looking only the MAC units, however, there are some differences in the number of units, the number of accumulators and so forth. In addition, the processing procedure influences the efficiency of memory accesses and the processing accuracy. It is known that the extra memory accesses affects the power consumption, and is very important problem. On the other hand, filter banks are known as an element technique of subband coding and wavelet coding. Thus, their efficient implementation is expected. In this report, firstly the unified representation of analyses and synthesis banks are introduced and then it is divided into two types of procedures. These procedures are investigated with MAC units of different architectures.

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  • 医療画像の蓄積と伝送に関する研究

    村松 正吾水谷, 佐藤,菊池, 佐々木,朱, 村松, 内藤,酒井

    電子情報通信学会信越支部大会  2000.10 

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  • 陪直交変調方式における繰り返し復調/復号に関する一検討

    滝沢,佐々木, 菊池,村松

    電子情報通信学会信越支部大会  2000.10 

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  • Zerotree Image Coding for Packet Transmission

    Shirai Michitomo, Muramatu Shougo, Sasaki Shigenobu, kikuchi Hisakazu

    Proceedings of the Society Conference of IEICE  2000.9 

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  • Motion Estimation with Power Scalability and Its VHDL Model

    TAKAGI Ayuko, MURAMATSU Shogo, KIYA Hitoshi

    Technical report of IEICE. DSP  1999.12 

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    In this paper, motion estimation with power scalability is proposed for low-bit motion estimation. To reduce the power of motion estimator, algorithms using less gray level image has been proposed. In the case of motion estimation with images of low-bit, the accuracy of motion estimation depends on the thresholds of the quantization and image degradation occurs. Using low-bit images, the power is proportional to bit width: less bit width results less power. There is a trade off between image quality and power. Low power is not always the desired condition, and we must be able to choose the suitable behavior for motion estimator from the viewpoint of both image quality and power. We propose an architecture for low-bit motion estimator which can select the desired bit width for image. By controlling the bit width, we can achieve the scalability of power for motion estimation. To verify the significance, the performance is estimated by using the synthesis result of the VHDL.

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  • A Hardware Architecture of Motion Estimator with 8x8 Block Mode for MPEG4 and Its VHDL Model

    SAKAMOTO Kenji, MURAMATSU Shogo, KIYA Hitoshi, YAMADA Akihiko

    Technical report of IEICE. DSP  1999.6 

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    In MPEG4, a new moving picture coding standard, there both 16×16 block mode and 8×8 block mode. In this report, we propose a linear array architecture of motion estimatior with 8×8 block mode. The proposed architecture is improved in both the internal of processing elements (PE) and comparator module from the conventional one. The input is the same as the conventional one. In the internal of PE, some multiplexers and an accumulater are added to the convetional architecture. The improvement of the conventional PE makes it possible to select and accumulate the sum of absolute differences (SAD) in the 8×8 block mode. Since the output timing of SAD in the 8×8 block mode differs from that of 16×16 block mode, This paper proposes two architecture for the 8×8 block mode. The verify the significance for VLSI implementation, the performance is estimated by using the synthesis result of the VHDL.

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  • A VLSI Architecture of Median-Cut Quantization for Low-Bit Motion Estimation

    MURAMATSU Shogo, KIYA Hitoshi, YAMADA Akihiko

    Technical report of IEICE. DSP  1999.6 

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    In this work, a bit-operation algorithm for the median-cut quantization (MCQ) is proposed and then the VLSI architecture is provided for low-bit block matching motion estimation. MCQ is the thechnique that reduces multi-valued samples to binary-valued ones by adaptively taking the median value as the threshold. In the proposed method, the search process of the median value is derived from the quick-sort algorithm. Samples are quantized during the search process. Firstly, the bit-serial procedure is shown, and then it is modified to the bit-parallel procedure. The extension to the multi-level quantization is also discussed. Since the proposed algorithm is based on bit poerations, it is suitable for the VLSI implementation. To verify the significance, for the application to the motion estimation, the performance is estimated from the synthesis result of the VHDL model.

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  • A Linear Array Architecture of Motion Estimator with 8×8 Block Mode for MPEG4

    SAKAMOTO Kenji, MURAMATSU Shogo, KIYA Hitoshi, YAMADA Akihiko

    Proceedings of the IEICE General Conference  1999.3 

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  • Hardware Model Based Evaluation of Irredundant Full Search Motion Estimation

    TAKAYAMA Katsumi, MURAMATSU Shogo, KIYA Hitoshi, YAMADA Akihiko

    Technical report of IEICE. VLD  1999.3 

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    This report evaluate an irredundant full search motion estimation with a hardware model. The behavior of this model is based on software pipelining with conditional branches. The model dynamically generates an instruction to execute a irredundant full search motion estimation and the instruction is generated from a code scheduled by software pipelinirag. Simulation results with this model shows a effectiveness of the behavior of this model and we present some required hardware resources,the number of some functional units, memory bandwidth, and required frequency for real time motion estimation.

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  • Improving the Computational Redundancy of Spatially Segmented Wavelet Transform

    MURAKAMI Masaharu, KIYA Hitoshi, MURAMATSU Shogo, KIMURA Seiji, FUKUHARA Takahiro

    IEICE technical report. Image engineering  1999.2 

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    In this report, we discuss tiling wavelet tranforms in which an input image is partitioned into tiles and then the wavelet transform is executed on each tile. One of the conventional tiling methods, Spatially Segmented Wavelet Transform (SSWT), needs overlapping tiles to avoid block distortion along the boundaries of the tiles. Moreover, the overlap size of tiles must be decided by the number of stage S and the length of filters L, before executing the transformation. It approximately increases in proportion to 2^<S-1> and L. These limitations generate a lot of redundant calculations and disturb the adaptive transformations. In this report, we propose a new tiling method which gives the same wavelet coefficients as those of the SSWT, by using different approach. Thus, the proposed method does not generate the block distortion. Since the overlap size of tiles in the proposed method is independent of the number of stage S, it is possible to improve both problems of computational redundancy and adaptive transformation.

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  • Multidimensional Filter Banks Without Checkerboard Effects

    HARADA Yasuhiro, MURAMATSU Shogo, KIYA Hitoshi

    Technical report of IEICE. DSP  1997.10 

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    The checkerboard effect is caused by the periodic time-variant property of interpolators which compose a multirate system. Although the condition for some multirate systems to avoid the checkerboard effect has been shown, the checkerboard effect in multidimensional filter banks has not been considered. In this paper, the condition for multidimensional filter banks to avoid the checkerboard effect is considered. Besides, the properties of the multidimensional filters with no checkerboard effect are given, and it is shown that necessary and sufficient condition for one dimensional multirate filters with no checkerboard effect is not necessary and sufficient one for multidimensional filters but sufficient one. Simulation examples show that the checkerboard effect can be avoided by using the proposed condition.

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  • Checkerboard Effects in Multidimensional Multirate Systems

    HARADA Yasuhiro, MURAMATSU Shogo, KIYA Hitoshi

    Technical report of IEICE. DSP  1997.6 

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    The checkerboard effect is caused by the periodic time-variant property of the interpolator which composes a multirate system. Although the condition for one-dimensional multirate systems with no checerboard effect has been shown, the checkerboard effect in multidimensional multirate systems has not been considered. In this paper, the condition for multidimensional sampling rate conversion with no checkerboard effect is considerd. Simulation examples show that the checkerboard effect can be avoided by using the proposed condition.

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  • A Design Method of Multidimensional Linear-Phase Paraunitary Filter Banks with a Lattice Structure

    MURAMATSU Shogo, YAMADA Akihiko, KIYA Hitoshi

    Technical report of IEICE. DSP  1997.6 

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    In this work, a lattice structure of multidimensional linear-phase paraunitary filter banks (MD-LPPUFB) is proposed so as to design such systems in a systematic way. Our proposed structure has a capability to produce MD-LPPUFB whose filters all have the region of support generated by the product of the decimation matrix M with an extension matrix, which is introduced to extend the region of support generated by M. Since both of the paraunitary and linear-phase properties are structurely restricted, an unconstrained optimization process can be used to design it. Our proposed structure is developed for both of even and odd number of channels, and includes the conventional 1D system as a special case. Some design examples show the significance of our proposed structure, where both of the rectangular and non-rectangular decimation cases are given.

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  • A JPEG/MPEG-Compatible Subband Coding System

    MURAMATSU Shogo, YAMADA Akihiko, KIYA Hitoshi

    Technical report of IEICE. DSP  1997.3 

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    In this report, a structure of JPEG/MPEG-compatible subband codec (SBC) system is proposed on the basis of the generalized lapped orthogonal transform (GenLOT). Compatible here means the ability of SBC systems to encode and decode the standard bit-streams. Since our proposed structure consists of the discrete cosine transform (DCT) employed in JPEG and MPEG, the compatibility can be simply achieved. The structure also enables us to process DCT coefficients and subband signals of GenLOT in common. Furthermore, it employs an efficient structure of GenLOT for finete-duration sequences, which based on the symmetric extension method, so as to avoid the size-increasing of subband signals. Hence, our proposed structure is shown to provide all efficient JPEG/MPEG-compatible SBC system, which has no redundancy due to the signal extension and no size-increasing. In addition, it has an advantage or no checkerboard artifact addressed for SBC system.

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  • Implementation of Sampling Rate Conversion With Fewer Delay

    ZOU Xiaoxia, MURAMATSU Shogo, KIYA Hitoshi

    Technical report of IEICE. DSP  1996.12 

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    Input-output delay caused by using fast Fourier transform (FFT) in sampling rate conversion system is considered in this paper. The proposed method can avoid the redundant operations caused by sampling rate conversion completely and moreover has fewer input-output delay for FIR filtering based on FFT. The relationship between the input-output delay and the opttimum block size corresponding to the computational complexity is investigated for the proposed method. As a result, it is shown that a good tradeoff between the computational complexity and input-output delay can be achieved.

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  • Two-Channel QMF Banks without Checkerboard Effect

    HARADA Yasuhiro, MURAMATSU Shogo, KIYA Hitoshi

    IEICE technical report. Circuits and systems  1996.9 

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    Although filter banks are designed to have the perfect reconstruction property, this property is not satisfied in some practical applications. In this case, filter banks behave as time-variant systems. As a result, the checkerboard effect is caused. In this paper, the condition for two channel filter banks with no checkerboard effect is shown, and for two channel FIR paraunitary QMF banks with real coefficients, a new design method to satisfy the condition is proposed. Our proposed method has a complete expression, and can be performed as unconstrained optimization.

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  • An Efficient Structure of Generalized LOT for Finite-Duration Sequences : Efficient implementation of a symmetric extension method

    MURAMATSU Shogo, KIYA Hitoshi

    Technical report of IEICE. DSP  1996.7 

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    The generalized lapped orthogonal transform (GenLOT) is expected to be applied to subband image coding. In this work, an efficient structure of GenLOT for finite-duration sequences is proposed. Since the linear filtering of finite-duration sequences generates longer duration outputs, it is not desirable to use it in image processing. Thus, to solve this provlem, the symmetric extension method has been proposed. It is the technique which symmetrically and periodically extends their inputs before convolving, and is superior to circular convolution in terms of the less distorition at the boundaries. Our proposed structure is derived from the symmetric extension method. In fact, the structure does not require any extension of sequences, and the conventional fast algorithm is still available. Furthermore, our proposed structure can be regarded as a generalized one of lapped orthogonal transforms (LOT) for finite-duration sequences.

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  • Evolution of Linear-Phase Orthonormal M-band DTWT using the modified GenLOT

    Harada Yasuhiro, Muramatu Shogo, Kiya Hitoshi

    Proceedings of the IEICE General Conference  1996.3 

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    本報告では、先に我々が提案した改良GenLOT(一般化重複直交変換)の直線位相正規直交M帯域DTWT(離散時間ウェーブレット変換)への応用を検討する。この際、従来のGenLOT及び、コサイン変調に基づくパラユニタリフィルタバンクの一種である拡張重複変換(ELT)を用いたM帯域DTWTと、符号化利得及び演算量の点で比較を行なう。これらの比較により改良GenLOTの有効性を確認する。

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  • A Design Method of Oversampled Paraunitary DFT Filter Banks using Householder's factorization

    KAJITA Kuniyuki, KOBAYASHI Hiroyuki, MURAMATSU Shogo, YAMADA Akihiko, KIYA Hitoshi

    Technical report of IEICE. DSP  1995.12 

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    It is known that there exists FIR filters which satisfy perfect reconstruction condition of oversampled DFT filter banks. However, the general design methods are not addressed. In this work we propose a design method of oversampled DFT filter banks using paraunitary property which enable us to choose arbitray decimation ratio D less than the number of channel M, under filter length as the multiple of common number of M and D. Our proposed method gives us perfect reconstruction FIR DFT filter banks with sufficient stopband attenuation which is important for applying to subband adaptive filters. Besides, we also show a design method for oversampled paraunitary DFT filter banks with linear phases. In order to show effectiveness of our method, we give design examples.

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  • On Image Interpolation with DCT-II : the Investigation Based on Symmetric Convolution and the Reduction of Blocking Artifacts

    MURAMATSU Shogo, KIYA Hitoshi

    IEICE technical report. Circuits and systems  1995.6 

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    In the interpolation of an image with type-II discrete cosine transform (DCT-II), there is a problem that produced images exhibit the visually annoying blocking artifact. In this work, the problem is theoretically investigated, and a method to solve it is proposed. Firstly, sampling-rate conversion with symmetric convolution is considered. Then, by regarding the interpolation with DCT-II as the special case of the conversion, the cause of blocking artifacts is investigated. Following this investigation, a technique using overlap-add method to reduce the blocking artifact is proposed, and so is a pseudo overlap-add method for the computational efficiency. And finally, the effectiveness of our proposed method is verified by simulation examples.

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  • A-129 A Multidimensional Extended Overlap-Add and -Save Method for Arbitrary Sampling Lattice Alteration

    MURAMATSU Shogo, KIYA Hitoshi

    電子情報通信学会秋季大会講演論文集  1994.9 

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Works

Awards

  • Distinguished Lecturer Program Certificate

    2020.12   APSIPA  

    Shogo MURAMATSU

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  • 編集活動貢献賞

    2019.9   電子情報通信学会 基礎・境界ソサイエティ  

    村松 正吾