MOTION VECTOR CALCULATION METHOD, IMAGE CODING METHOD, IMAGE DECODING METHOD, MOTION VECTOR CALCULATION DEVICE AND IMAGE CODING/DECODING DEVICE

摘要

A motion vector calculation method for improving the compression rate comprises: a selection step for selecting one reference motion vector which a reference block has; and a calculation step for calculating the motion vector of a block to be processed using the one reference motion vector selected in the selection step. In the selection step, when the reference block has two reference motion vectors (S121), one reference motion vector is selected from the two reference motion vectors on the basis of whether the reference block is located in front of or behind the block to be processed in display time order (S123, S124), and when the reference block has only one reference motion vector (S125, S127), the one reference motion vector is selected (S126, S128).