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Dive into the research topics where Jun Murayama is active.

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Featured researches published by Jun Murayama.


international conference on neural information processing | 2013

Image Denoising Based on Overcomplete Topographic Sparse Coding

Haohua Zhao; Jun Luo; Zhiheng Huang; Takefumi Nagumo; Jun Murayama; Liqing Zhang

This paper presents a novel image denoising framework using overcomplete topographic model. To adapt to the statistics of natural images, we impose sparseness constraints on the denoising model. Based on the overcomplete topographic model, our denoising system improves over previous work on the following aspects: multi-category based sparse coding, adaptive learning, local normalization, and shrinkage function. A large number of simulations have been performed to show the performance of the modified model, demonstrating that the proposed model achieves better denoising performance.


Neural Processing Letters | 2015

Statistically Adaptive Image Denoising Based on Overcomplete Topographic Sparse Coding

Haohua Zhao; Jun Luo; Zhiheng Huang; Takefumi Nagumo; Jun Murayama; Liqing Zhang

This paper presents a novel image denoising framework using overcomplete topographic model. To adapt to the statistics of natural images, we impose both spareseness and topograpgic constraints on the denoising model. Based on the overcomplete topographic model, our denoising system improves the previous work on the following aspects: multi-category based sparse coding, adaptive learning, local normalization, lasso shrinkage function, and subset selection. A large number of simulations have been performed to show the performance of the modified model, demonstrating that the proposed model achieves better denoising performance.


international electron devices meeting | 2016

Four-directional pixel-wise polarization CMOS image sensor using air-gap wire grid on 2.5-μm back-illuminated pixels

Tomohiro Yamazaki; Yasushi Maruyama; Yusuke Uesaka; Motoaki Nakamura; Yoshihisa Matoba; Takashi Terada; Kenta Komori; Yoshiyuki Ohba; Shinichi Arakawa; Yasutaka Hirasawa; Yuhi Kondo; Jun Murayama; Kentaro Akiyama; Yusuke Oike; Shuzo Sato; Takayuki Ezaki

Polarization information is useful in highly functional imaging. This paper presents a four-directional pixel-wise polarization CMOS image sensor using an air-gap wire grid on 2.5-μm back-illuminated pixels. The fabricated air-gap wire grid polarizer achieved a transmittance of 63.3 % and an extinction ratio of 85 at 550 nm, outperforming conventional polarization sensors. The pixel-wise polarizers fabricated with the wafer process on back-illuminated image sensors exhibit good oblique-incidence characteristics, even with small polarization pixels of 2.5 μm. The proposed image sensor realizes mega-pixel various fusion-imaging applications, such as surface reflection reduction, highly accurate depth mapping, and condition-robust surveillance.


Archive | 2001

Coding apparatus, coding method and recording medium having coded program recorded therein, and decoding apparatus, decoding method and recording medium having decoded program recorded therein

Jun Murayama; Masayuki Hattori; Toshiyuki Miyauchi; Kouhei Yamamoto; Takashi Yokokawa


Archive | 2011

Video-information encoding method and video-information decoding method

Yoichi Yagasaki; Osamu Sunohara; Jun Murayama


Archive | 2010

Image Processing Apparatus and Method, Learning Apparatus and Method, and Program

Kazuki Aisaka; Masatoshi Yokokawa; Jun Murayama


Archive | 2001

Method and apparatus for reproducing data and method and apparatus for recording and/or reproducing data

Masayuki Hattori; Jun Murayama; Toshiyuki Miyauchi


Archive | 1997

Viterbi decoding apparatus and viterbi decoding method

Jun Murayama


Archive | 2011

Device, Method, and Program for Image Processing

Kazuki Aisaka; Masatoshi Yokokawa; Nodoka Tokunaga; Jun Murayama


Archive | 1999

Turbo coding, decoding devices and turbo coding, decoding methods

Jun Murayama; Robert J. McEliece; Masayuki Hattori

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Haohua Zhao

Shanghai Jiao Tong University

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Liqing Zhang

Shanghai Jiao Tong University

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Zhiheng Huang

Shanghai Jiao Tong University

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