GROUPES DE TRANSFORMÉES POUR LA SÉLECTION LOCALE D'UN ENSEMBLE DE TRANSFORMÉES EN CODAGE VIDÉO

摘要

A method and apparatus for improving the performance of video encoders and decoders involves selecting a set of transforms from among a plurality of sets of transforms that can be used for coding blocks in a region of a video image. Within a region, selection of a particular transform from among a plurality of transforms comprising the selected set of transforms is used to encoder or decode at least one block in the region. Associated indices representing the set of transforms to be used within a region and the selected transform for a block can be sent in a bitstream. In an alternate embodiment, a default set of transforms is complemented by selection of an additional set of transforms on a block or region basis.