A Rate-Constrained Block Matching Algorithm for Video Coding

The Rate Constrained Block Matching Algorithm, (RC-BMA), introduced in this paper, jointly minimizes Displaced Frame Di erence (DFD) variance and entropy or conditional entropy of motion vectors for determining the motion vectors. It is intended for use in low rate video coding applications where the contribution of the motion vector rate to the overall coding rate might be signi cant. The DFD variance vs. motion vector rate performance of RC-BMA employing size KxK blocks is shown to be superior to that of the conventional Minimum Distortion Block Matching Algorithm (MD-BMA) employing size 2Kx2K blocks. Constraining of the entropy or conditional entropy of motion vectors in RC-BMA results in smoother and more organized motion vector elds than those output by MD-BMA. The motion vector rate of RC-BMA can also be precisely controlled for each frame by adjusting a single parameter. Subject terms : Motion estimation, block matching, vector quantization, rate constraint, entropy constraint, video coding