Patent US RE40372

A motion vector prediction method in an error resilient mode. In the motion vector prediction method capable of decoding backwards, motion vectors of macro blocks are calculated, and motion vectors of macro blocks each having one motion vector are predicted while moving to another macro block from left to right, and motion vectors of macro blocks each having four motion vectors are continuously predicted in a predetermined sequence to have correlation in prediction of the four motion vectors. Thus, in the motion vector prediction method based on the image signal compression method of the MPEG-4 or H.263 standard, the motion vector prediction is performed with continuity and correlation among the motion vectors, so that two-way decoding is possible during transmission of blocks with a predetermined packet, resulting in better error resilient characteristics.