In Search of 'Better-than-DCT' Unitary Transforms for Encoding of Residual Signals
| Autor: | Siu-Kei Au Yeung, Bing Zeng, Shuyuan Zhu |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Karhunen–Loève theorem
Covariance matrix Applied Mathematics Speech recognition Markov process Residual Unitary state symbols.namesake Transformation matrix Computer Science::Multimedia Signal Processing symbols Discrete cosine transform Electrical and Electronic Engineering Algorithm Mathematics Coding (social sciences) |
| Zdroj: | IEEE Signal Processing Letters. 17:961-964 |
| ISSN: | 1558-2361 1070-9908 |
| Popis: | It is well known that the discrete cosine transform (DCT) closely approximates the optimal Karhunen-Loeve transform (KLT) under the first-order stationary Markov condition with a strong inter-pixel correlation. However, if the inter-pixel correlation is weak or becomes negative, transforms other than the DCT would possibly become better. In this letter, we present a design framework for finding new unitary transforms according to two principles: 1) they are indeed more efficient than the DCT in encoding of signals with a weak or negative inter-pixel correlation (e.g., the residual signals after motion-compensation or intra- prediction) and 2) each has a fixed transform matrix (i.e., signal-independent) and can be implemented as efficiently as the DCT. Some of the new transforms will be used to demonstrate an improved R-D performance in the video coding scenario. |
| Databáze: | OpenAIRE |
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