POST PROCESSING OF MOTION VECTORS USING SAD FOR LOW BIT RATE VIDEO COMPRESSION

A method and system for detecting and replacing spurious motion vectors in video signal compression includes determining whether a motion vector of a current macroblock is spurious by comparing the motion vector with motion vectors of motion vectors of neighbouring macroblocks; and replacing the motion vector as spurious if the difference exceeds a predetermined threshold. In particular, the method and system seeks to determine (72, 73) whether at least one cluster of motion vectors of neighbouring macroblocks can be formed; and if not, leaves (80) the motion vector of the current macroblock unchanged but if so determining (74) whether the motion vector falls within a cluster. The motion vector may be replaced (81) under certain criteria if the motion vector does not fall within a cluster of motion vectors of neighbouring macroblocks.