| Project/Area Number |
07650419
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
情報通信工学
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| Research Institution | Niigata University |
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Principal Investigator |
KIKUCHI Hisakazu Department of Electrical Engineering, Professor, 工学部, 教授 (70126407)
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| Co-Investigator(Kenkyū-buntansha) |
SASAKI Shigenobu Department of Electrical Engineering, Lecturer, 工学部, 講師 (20242399)
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| Project Period (FY) |
1995 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1997: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1996: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1995: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | image compression / wavelets / source and channel coding / image enhancement / mobile telecommunication / CDMA / spread apectrum / 画像符号化 / 階層的符号化 / 無線通信 / 多重解像度 / ベクトル量子化 |
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| Research Abstract |
A broader interest in this research is targeted at the mobile telecommunications for imagery. The purpose of study is to develop a quality high-speed layred transmission system for images. A platform for image representations is provided by the wavelet-based multiresolution representation, and the parallel combinatorial spread apectrum technology is assumed to be a promising wireless telecommunication system. Major results are summarized in four points as follows.
/1/A layred image coding scheme is studied to provide wide-range scalability with respect to both image quality and spatial resolution, and the coding scheme comprises a direct-product wavelet expansion, nonlinear quantization with dead bands, multi-stage zero runlength coding and arithmetic coding.
/2/For quality image transmission in mobile telecommunications, parallel combinatorial spread apectrum systems are investigated in conjunction with error correcting decoding, and also their bit error rate performances have been found to be significantly improved in typical multipath fading channels.
/3/Decoded image quality has been very improved in realistic wireless telecommunication environments by negotiable trade-off between a layred encoded data stream and additional error correcting codes.
/4/As an option at receivers, a new image enhancement method has been developed. It is a local feature-based estimation based on statistical knowledge described in a vector quantization code book, and the code book consists of typical behaviors of edges and outlines across scales in a wavelet-based multiresolution space.
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