MOTION VECTOR CONVERSION METHOD AND CONVERTER

摘要

PROBLEM TO BE SOLVED: To provide a motion vector conversion method by which a coding efficiency of image coding in compliance with the MPEG4 in an image information conversion method can be much more enhanced. SOLUTION: The motion vector conversion method generates a bit stream in compliance with the MPEG4 at a low frame rate and at a low bit rate by abandoning every other P frame of a bit stream in compliance with the MPEG2. This method also performs the motion vector conversion and motion vector smoothing, stores in advance macro blocks in the bit stream denoting received image compression information in compliance with the MPEG2 and information by each block, copies a motion vector of the P frame just before it is abandoned on the basis of the stored information, and doubly expands the copied motion vector in a temporal direction so as to generate a motion vector in compliance with the MPEG4 converted from an intra-frame in compliance with the MPEG2.