IMAGE SIGNAL CODING AND DECODING APPARATUS WITH MULTIPLE-PROCESS MOTIO N COMPENSATION

Image signal coding and decoding apparatus adapted to reduce the redundancy between motion vectors in divided blocks of an image to realize enhanced data compression. The coding apparatus comprises a local decoder for locally decoding quantized data; a motion detector for calculating the motion vectors of individual subblocks defined by dividing macroblocks for motion compensation of a dynamic image; a controller for selecting an optimal process for the motion vectors to minimize the redundancy; a motion compensator for forming a predictive image; and a difference calculator for calculating the difference between the predictive image and the original image signal corresponding thereto. The image signal decoding apparatus comprises an inverse multiplexer for separating the coded data into variable-length coded data and vector coded data; and a controller for selecting an optimal motion vector process on the basis of the vector coded data.