Rate-constrained block-matching algorithm

The rate constrained block matching algorithm (RC-BMA), introduced in this paper jointly minimizes DFD variance and entropy or conditional entropy of motion vectors for determining the motion vectors in low rate video coding applications where the contribution of the motion vector rate to the overall coding rate might be significant. The motion vector rate versus DFD variance 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 fields with respect to those output by MD-BMA. The motion vector rate of RC-BMA can also be fine tuned to a desired level for each frame by adjusting a single parameter.