Affiliation Department etc.

Department of Computer Science
Department of Computer Science



External Career

  • 2001.04

      Research Assistant  

  • 2004.04

      Associate Professor (as old post name)  

  • 2005.10

      Associate Professor  

  • 2015.05

    ESIEE Paris, France   Laboratoire d'Informatique Gaspard-Monge (LIGM), Équipe Algorithmes, Architectures, Analyse et Synthèse d'images (A3SI)   Researcher  

Academic Society Affiliations

  • 2002.03


Field of expertise (Grants-in-aid for Scientific Research classification)

  • Perceptual information processing



  • Localization of Flying Bats from Multichannel Audio Signals by Estimating Location Map with Convolutional Neural Networks

    Kazuki Fujimori, Bisser Raytchev, Kazufumi Kaneda, Yasufumi Yamada, Yu Teshima, Emyo Fujioka, Shizuko Hiryu, and Toru Tamaki

    Journal of Robotics and Mechatronics ( Fuji Technology Press Ltd )  33 ( 3 ) 515 - 525   2021.06  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

    We propose a method that uses ultrasound audio signals from a multichannel microphone array to estimate the positions of flying bats. The proposed model uses a deep convolutional neural network that takes multichannel signals as input and outputs the probability maps of the locations of bats. We present experimental results using two ultrasound audio clips of different bat species and show numerical simulations with synthetically generated sounds.

  • A Hardware Implementation on Customizable Embedded DSP Core for Colorectal Tumor Classification with Endoscopic Video toward Real-Time Computer-Aided Diagnosis System

    Masayuki ODAGAWA, Takumi OKAMOTO, Tetsushi KOIDE, Toru TAMAKI, Bisser RAYTCHEV, Kazufumi KANEDA, Shigeto YOSHIDA, Hiroshi MIENO, Shinji TANAKA, Takayuki SUGAWARA, Hiroshi TOISHI, Masayuki TSUJI, Nobuo TAMBA

    IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences ( IEICE )  E104-A ( 4 ) 691 - 701   2021.04  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

    In this paper, we present a hardware implementation of a colorectal cancer diagnosis support system using a colorectal endoscopic video image on customizable embedded DSP. In an endoscopic video image, color shift, blurring or reflection of light occurs in a lesion area, which affects the discrimination result by a computer. Therefore, in order to identify lesions with high robustness and stable classification to these images specific to video frame, we implement a computer-aided diagnosis (CAD) system for colorectal endoscopic images with Narrow Band Imaging (NBI) magnification with the Convolutional Neural Network (CNN) feature and Support Vector Machine (SVM) classification. Since CNN and SVM need to perform many multiplication and accumulation (MAC) operations, we implement the proposed hardware system on a customizable embedded DSP, which can realize at high speed MAC operations and parallel processing with Very Long Instruction Word (VLIW). Before implementing to the customizable embedded DSP, we profile and analyze processing cycles of the CAD system and optimize the bottlenecks. We show the effectiveness of the real-time diagnosis support system on the embedded system for endoscopic video images. The prototyped system demonstrated real-time processing on video frame rate (over 30fps @ 200MHz) and more than 90% accuracy.

  • Spectral Rendering of Fluorescence on Translucent Materials

    Masaya Kugita, Kazufumi Kaneda, Bisser Raytchev, Toru Tamaki

      20 ( 1 ) 30 - 39   2021.03  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

    To render fluorescence, a wavelength dependent phenomena, we need to take into account the spectral distribution of light. Moreover, for translucent fluorescent medium we need to consider subsurface scattering. We propose a spectral rendering method to render fluorescence on translucent materials under global illumination environment. The proposed method is based on the physical properties of the fluorescence phenomena and rendered in a Probabilistic Progressive Photon Mapping method. By separating the power of photons into 3 elements (fluorescence, single scattering, multiple scattering), our method realizes fluorescence taking into account the scattering and absorption of light under the surface. We also introduce the Photon Power Table used for calculating the illuminance efficiently and deciding the outgoing point of light probabilistically. Finally, we show the usefulness of our method by demonstrating the rendered image.

  • Rephrasing visual questions by specifying the entropy of the answer distribution

    Kento Terao, Toru Tamaki, Bisser Raytchev, Kazufumi Kaneda, Shin’Ichi Satoh

    IEICE TRANSACTIONS on Information and Systems ( IEICE )  E103-D ( 11 ) 2362 - 2370   2020.11  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

  • An Entropy Clustering Approach for Assessing Visual Question Difficulty

    Kento Terao, Toru Tamaki, Bisser Raytchev, Kazufumi Kaneda, Shin'ichi Satoh

    IEEE Access ( IEEE )  8   180633 - 180645   2020.09  [Refereed]

    Research paper (scientific journal)   Multiple Authorship


  • Biomedical Engineering

    Tetsushi Koide, Toru Tamaki, Shigeto Yoshida, and Shinji Tanaka (Part: Multiple Authorship ,  A Hierarchical Type Segmentation Hardware for Colorectal Endoscopic Images with Narrow Band Imaging Magnification )

    Jenny Stanford Publishing  2021.11 ISBN: 9789814877633

    Several developed countries are facing serious problems in medical environments owing to the aging society, and extension of healthy lifetime has become a big challenge. Biomedical engineering, in addition to life sciences and medicine, can help tackle these problems. Innovative technologies concerning minimally invasive treatment, prognosis and early diagnosis, point-of-care testing, regenerative medicine, and personalized medicine need to be developed to realize a healthy aging society.

    This book presents cutting-edge research in biomedical engineering from materials, devices, imaging, and information perspectives. The contributors are senior members of the Research Center for Biomedical Engineering, supported by the Ministry of Education, Culture, Sports, Science and Technology, Japan. All chapters are results of collaborative research in engineering and life sciences and cover nanotechnology, materials, optical sensing technology, imaging technology, image processing technology, and biomechanics, all of which are important areas in biomedical engineering. The book will be a useful resource for researchers, students, and readers who are interested in biomedical engineering.


  • Estimating the number of Table Tennis Rallies in a Match Video

    Shoma Kato, Akira Kito, Toru Tamaki, Hiroaki Sawano

    International Workshop on Advanced Image Technology 2022 (IWAIT 2022)  2022.01  -  2022.01 

  • On the Instability of Unsupervised Domain Adaptation with ADDA

    Kazuki Omi, Toru Tamaki

    International Workshop on Advanced Image Technology 2022 (IWAIT 2022)  2022.01  -  2022.01 

  • p-TSM: Learning to shift temporal features point-wise for action recognition

    Wataru Fuji, Bisser Raytchev, Kazufumi Kaneda and Toru Tamaki

    The International Workshop on Frontiers of Computer Vision (IW-FCV2021)  (online)  2021.02  -  2021.02 

  • Weakly supervised temporal action localization with additional sub networks for local spatial information

    Komiki Maruyama, Bisser Raytchev, Kazufumi Kaneda and Toru Tamaki

    The International Workshop on Frontiers of Computer Vision (IW-FCV2021)  (online)  2021.02  -  2021.02 

  • Which visual questions are difficult to answer? Analysis with Entropy of Answer Distributions

    Kento Terao, Toru Tamaki, Bisser Raytchev, Kazufumi Kaneda, Shun'ichi Satoh

    Visual Question Answering and Dialog Workshop at CVPR 2020  (online)  2020.06  -  2020.06 

  • Video Captioning with Dot Attention

    Komiki Maruyama, Toru Tamaki, Bisser Raytchev and Kazufumi Kaneda

    The International Workshop on Frontiers of Computer Vision (IW-FCV2020)  (Ibusuki, Oita, Japan)  2020.02  -  2020.02 

  • Pose Estimation of Excavators

    Hinako Nakamura, Yumeno Tsukada, Toru Tamaki, Bisser Raytchev and Kazufumi Kaneda

    The 23rd International Workshop on Advanced Image Technology (IWAIT2020)  (Yogyakarta, Indonesia)  2020.01  -  2020.01 

  • A Method for Rendering Wavelength-dependent Phenomena Using Spectral Image-based Lighting

    Toru Nagai, Bisser Raytchev, Toru Tamaki and Kazufumi Kaneda

    The 23rd International Workshop on Advanced Image Technology (IWAIT2020)  (Yogyakarta, Indonesia)  2020.01  -  2020.01 

Grant-in-Aid for Scientific Research

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