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[Author] Masakazu IWAMURA(5hit)

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  • Individuality-Preserving Silhouette Extraction for Gait Recognition and Its Speedup

    Masakazu IWAMURA  Shunsuke MORI  Koichiro NAKAMURA  Takuya TANOUE  Yuzuko UTSUMI  Yasushi MAKIHARA  Daigo MURAMATSU  Koichi KISE  Yasushi YAGI  

     
    PAPER-Pattern Recognition

      Pubricized:
    2021/03/24
      Vol:
    E104-D No:7
      Page(s):
    992-1001

    Most gait recognition approaches rely on silhouette-based representations due to high recognition accuracy and computational efficiency. A fundamental problem for those approaches is how to extract individuality-preserved silhouettes from real scenes accurately. Foreground colors may be similar to background colors, and the background is cluttered. Therefore, we propose a method of individuality-preserving silhouette extraction for gait recognition using standard gait models (SGMs) composed of clean silhouette sequences of various training subjects as shape priors. The SGMs are smoothly introduced into a well-established graph-cut segmentation framework. Experiments showed that the proposed method achieved better silhouette extraction accuracy by more than 2.3% than representative methods and better identification rate of gait recognition (improved by more than 11.0% at rank 20). Besides, to reduce the computation cost, we introduced approximation in the calculation of dynamic programming. As a result, without reducing the segmentation accuracy, we reduced 85.0% of the computational cost.

  • Data Embedding into Characters Open Access

    Koichi KISE  Shinichiro OMACHI  Seiichi UCHIDA  Masakazu IWAMURA  Marcus LIWICKI  

     
    INVITED PAPER

      Vol:
    E98-D No:1
      Page(s):
    10-20

    This paper reviews several trials of re-designing conventional communication medium, i.e., characters, for enriching their functions by using data-embedding techniques. For example, characters are re-designed to have better machine-readability even under various geometric distortions by embedding a geometric invariant into each character image to represent class label of the character. Another example is to embed various information into handwriting trajectory by using a new pen device, called a data-embedding pen. An experimental result showed that we can embed 32-bit information into a handwritten line of 5 cm length by using the pen device. In addition to those applications, we also discuss the relationship between data-embedding and pattern recognition in a theoretical point of view. Several theories tell that if we have appropriate supplementary information by data-embedding, we can enhance pattern recognition performance up to 100%.

  • Learning Multi-Level Features for Improved 3D Reconstruction

    Fairuz SAFWAN MAHAD  Masakazu IWAMURA  Koichi KISE  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2022/12/08
      Vol:
    E106-D No:3
      Page(s):
    381-390

    3D reconstruction methods using neural networks are popular and have been studied extensively. However, the resulting models typically lack detail, reducing the quality of the 3D reconstruction. This is because the network is not designed to capture the fine details of the object. Therefore, in this paper, we propose two networks designed to capture both the coarse and fine details of the object to improve the reconstruction of the detailed parts of the object. To accomplish this, we design two networks. The first network uses a multi-scale architecture with skip connections to associate and merge features from other levels. For the second network, we design a multi-branch deep generative network that separately learns the local features, generic features, and the intermediate features through three different tailored components. In both network architectures, the principle entails allowing the network to learn features at different levels that can reconstruct the fine parts and the overall shape of the reconstructed 3D model. We show that both of our methods outperformed state-of-the-art approaches.

  • Learning Pyramidal Feature Hierarchy for 3D Reconstruction

    Fairuz Safwan MAHAD  Masakazu IWAMURA  Koichi KISE  

     
    LETTER-Image Recognition, Computer Vision

      Pubricized:
    2021/11/16
      Vol:
    E105-D No:2
      Page(s):
    446-449

    Neural network-based three-dimensional (3D) reconstruction methods have produced promising results. However, they do not pay particular attention to reconstructing detailed parts of objects. This occurs because the network is not designed to capture the fine details of objects. In this paper, we propose a network designed to capture both the coarse and fine details of objects to improve the reconstruction of the fine parts of objects.

  • Exploring Sensor Modalities to Capture User Behaviors for Reading Detection

    Md. Rabiul ISLAM  Andrew W. VARGO  Motoi IWATA  Masakazu IWAMURA  Koichi KISE  

     
    LETTER-Human-computer Interaction

      Pubricized:
    2022/06/20
      Vol:
    E105-D No:9
      Page(s):
    1629-1633

    Accurately describing user behaviors with appropriate sensors is always important when developing computing cost-effective systems. This paper employs datasets recorded for fine-grained reading detection using the J!NS MEME, an eye-wear device with electrooculography (EOG), accelerometer, and gyroscope sensors. We generate models for all possible combinations of the three sensors and employ self-supervised learning and supervised learning in order to gain an understanding of optimal sensor settings. The results show that only the EOG sensor performs roughly as well as the best performing combination of other sensors. This gives an insight into selecting the appropriate sensors for fine-grained reading detection, enabling cost-effective computation.