Very low bit-rate video coding based on matching pursuits
We present a video compression algorithm which performs well on generic sequences at very low bit rates. This algorithm was the basis for a submission to the November 1995 MPEG-4 subjective tests. The main novelty of the algorithm is a matching-pursuit based motion residual coder. The method uses an inner-product search to decompose motion residual signals on an overcomplete dictionary of separable Gabor functions. This coding strategy allows residual bits to be concentrated in the areas where they are needed most, providing detailed reconstructions without block artifacts. Coding results from the MPEG-4 Class A compression sequences are presented and compared to H.263. We demonstrate that the matching pursuit system outperforms the H.263 standard in both peak signal-to-noise ratio (PSNR) and visual quality.