| Presentation | 2023-02-02 [Invited Talk] How Can We Compress Signs of DCT Coefficients in Image Coding? Chihiro Tsutake, |
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| PDF Download Page |  PDF download Page Link |
| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | Compressing the signs of DCT coefficients is an intractable problem in image coding because of their equiprobable characteristics. To overcome this difficulty, we have proposed a novel method named sign retrieval that can restore the signs only from the DCT magnitudes. This method is inspired by a classical image restoration problem referred to as phase retrieval, which aims to find the phases of DFT coefficients only from their magnitudes. More specifically, we regard the DCT magnitudes and signs as the DFT magnitudes and phases in the phase retrieval problem, respectively, and we restore the signs via a phase retrieval solver. We have achieved the sign compression by using our sign retrieval. More specifically, we first compress DCT magnitudes at an encoder; we then restore the signs of DCT coefficients, and finally compress error-correction codes. If the signs can be restored with high accuracy, the error-correction codes have small entropy, i.e., compressible. By adding the error-correction codes to the restored signs, we can obtain the original signs without errors. In this talk, we review our research on the sign compression, and report the effectiveness of our method for still image coding and video one. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | image coding / phase retrieval / sign retrieval / sign compression / convex optimization / neural network |
| Paper # | IE2022-55 |
| Date of Issue | 2023-01-26 (IE) |
| Conference Information | |
| Committee | IE |
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| Conference Date | 2023/2/2(1days) |
| Place (in Japanese) | (See Japanese page) |
| Place (in English) | NII |
| Topics (in Japanese) | (See Japanese page) |
| Topics (in English) | Image Processing |
| Chair | Kazuya Kodama(NII) |
| Vice Chair | Hiroyuki Bandoh(NTT) / Toshihiko Yamazaki(Univ. of Tokyo) |
| Secretary | Hiroyuki Bandoh(KDDI Research) / Toshihiko Yamazaki(Nagoya Inst. of Tech.) |
| Assistant | Shunsuke Iwamura(NHK) / Shinobu Kudo(NTT) |
| Paper Information | |
| Registration To | Technical Committee on Image Engineering |
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| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | [Invited Talk] How Can We Compress Signs of DCT Coefficients in Image Coding? |
| Sub Title (in English) | A Method Inspired by Phase Retrieval |
| Keyword(1) | image coding |
| Keyword(2) | phase retrieval |
| Keyword(3) | sign retrieval |
| Keyword(4) | sign compression |
| Keyword(5) | convex optimization |
| Keyword(6) | neural network |
| 1st Author's Name | Chihiro Tsutake |
| 1st Author's Affiliation | Nagoya University(Nagoya Univ.) |
| Date | 2023-02-02 |
| Paper # | IE2022-55 |
| Volume (vol) | vol.122 |
| Number (no) | IE-376 |
| Page | pp.pp.19-19(IE), |
| #Pages | 1 |
| Date of Issue | 2023-01-26 (IE) |