Hybrid Video Coding Based on Bidimensional Matching Pursuit

Hybrid video coding combines together two stages: first motion estimation and compensation predict each frame from the neighboring frames, then the prediction error is coded, reducing the correlation in the spatial domain. In this work we focus on the latter stage, presenting a scheme that profits of some of the features introduced by the standard H.264/AVC for motion estimation and replaces the transform in the spatial domain. The prediction error is so coded using the Matching Pursuit algorithm which decomposes the signal over an appositely designed bi-dimensional, anisotropic, redundant dictionary. Comparisons are made among the proposed technique, H.264 and a DCT-based coding scheme. Moreover, we introduce fast techniques for atom selection, which exploit the spatial localization of the atoms. An adaptive coding scheme aimed at optimizing the resource allocation is also presented, together with a rate-distortion study for the Matching Pursuit algorithm. Results show that the proposed scheme outperforms the standard DCT, especially at very low bit-rates