Matching pursuits video coding: Dictionaries and fast implementation

Matching pursuits over a basis of separable Gabor functions has been demons trated to outperform DCT methods for displaced frame difference coding for video compression, Unfortunately, apart from very low bit-rate applications , the algorithm involves an extremely high computational load. This paper c ontains original contribution to the issues of dictionary selection and fas t implementation for matching pursuits video coding. First, it is shown tha t the PSNR performance of existing matching pursuits codecs can be improved and the implementation cost reduced by a better selection of dictionary fu nctions. Secondly, dictionary factorization is put forward to further reduc e implementation costs. A reduction of the computational load by a factor o f 20 is achieved compared to implementations reported to date. For a majori ty of test conditions, this reduction is supplemented by an improvement in reconstruction quality. Finally, a pruned full-search algorithm is introduc ed, which offers significant quality gains compared to the better-known heu ristic fast-search algorithm, while keeping the computational cost low.