| Presentation | 2001/4/13 A Lapped Biorthogonal Transform Adapted for Local Directionality of Images and Its Applications in Image Coding Toshihisa TANAKA, Yukihiko YAMASHITA, |
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| PDF Download Page | PDF download Page Link |
| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | We present the theory and design of an adaptive lapped biorthogonal transform for image coding. The proposed transform consists of basis functions overlapping across adjacent blocks and non-overlapping basis functions, where the basis functions' centers of symmetry are aligned. Because of the alignment, we can use the symmetric extension method at image boundaries when we transform an input image. Next, we show that the optimal non-overlapping basis functions in the minimal mean square error sense can be found by solving an eigenvalue problem without numerical search when the overlapping basis functions are given. This derivation is enabled by the subspace Karhunen-Loeve transform (SKLT) which provides the optimal approximation of an original signal in a given subspace, and which has been proposed by the present authors. We show an orientation adaptive example, where each adaptive transform is characterized by the angle of edges in image blocks. In the encoder, each block is selectively transformed by one of orientation adaptive transforms. Experimental results show that the use of adaptation improves the quality of decoded images. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | transform coding / lapped transform / biorthogonal transform / adaptive transform / subspace KLT |
| Paper # | DSP2001-1,IE2001-1,MI2001-1 |
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| Conference Information | |
| Committee | IE |
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| Conference Date | 2001/4/13(1days) |
| Place (in Japanese) | (See Japanese page) |
| Place (in English) | |
| Topics (in Japanese) | (See Japanese page) |
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| Paper Information | |
| Registration To | Image Engineering (IE) |
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| Language | ENG |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | A Lapped Biorthogonal Transform Adapted for Local Directionality of Images and Its Applications in Image Coding |
| Sub Title (in English) | |
| Keyword(1) | transform coding |
| Keyword(2) | lapped transform |
| Keyword(3) | biorthogonal transform |
| Keyword(4) | adaptive transform |
| Keyword(5) | subspace KLT |
| 1st Author's Name | Toshihisa TANAKA |
| 1st Author's Affiliation | Department of International Development Engineering Graduate School of Science and Engineering Tokyo Institute of Technology() |
| 2nd Author's Name | Yukihiko YAMASHITA |
| 2nd Author's Affiliation | Department of International Development Engineering Graduate School of Science and Engineering Tokyo Institute of Technology |
| Date | 2001/4/13 |
| Paper # | DSP2001-1,IE2001-1,MI2001-1 |
| Volume (vol) | vol.101 |
| Number (no) | 19 |
| Page | pp.pp.- |
| #Pages | 8 |
| Date of Issue | |