Abstract:A new motion estimation algorithm based on spatio-temporal cohenence is presented. In this proposed algorithm, an initial motion vector of the block which has good coherence with its neighbors or that of the previous frame is directly predicated. A more precise motin vector is obtained based on the initial one by full-searching block matching algorithm (FBMA) in a small range. As to blocks with poor coherence, FBMA with ordinary range is used, and their motion vectors are at last adjusted by the coherence criterion given in the paper. Experiments show satisfying results can be reached with the proposed algorithm.