Method and apparatus for most probable mode (MPM) reordering for intra prediction

摘要

To construct an MPM set for encoding or decoding an intra prediction mode, a plurality of neighbor blocks may be used. In one implementations, two above-intermediate neighbor blocks, such as those specified by sample locations at a distance equal to the height or half of the width may be used for a flat rectangular block, or two left-intermediate neighbor blocks, such as those specified by sample locations at a distance equal to the width or half of the height may be used for a tall rectangular block. The order of searching the neighbor blocks can be based on the current block's shape, or based on the distance between a neighbor's intra prediction mode and a vertical or horizontal intra prediction mode. Both the encoder and decoder follow the same MPM set construction process. Hence, no additional syntax elements are needed to signal the neighbor blocks and the search order.