Video Encoding and Decoding with Chrominance Sub-sampling

摘要

A method of video encoding utilising a transform operation on separate luminance and chrominance transform blocks. Luminance and chrominance information relating to a common image region is received, the chrominance information being horizontally sub-sampled with respect to the luminance information (such as in the 4:2:2 sub-sampling format.) Square luminance transform blocks are formed by quad-tree splitting of the received luminance information and square chrominance transform blocks are formed by binary splitting and quad-tree splitting of the received chrominance information. Entropy encoding is then performed on each luminance and chrominance transform block, optionally preceded by transform and/or quantisation. The luminance and chrominance information may optionally represent residual luminance and chrominance after deduction of a prediction for the common image region or part of the common image region. The binary splitting of the chrominance information may be conducted in a root block preceding the quadtree splitting. Also disclosed in an equivalent method of video decoding.