Temporal prediction of block motion vectors with local ambiguity-based adaptivity
Stephen O'Halek, Ken D. Sauer · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1994
The computational burden of full search block matching algorithms for motion estimation in video coding can be reduced through exploitation of spatial and temporal correlation of the motion vectors. This paper describes a simple adaptive temporal prediction scheme for block motion vectors. The first-order temporal predictor determines the center of the search area for a conventional block match, but with substantially reduced search radius. The abbreviated search reduces computation by about 75% for blocks whose motion is successfully predicted. Adaptivity is introduced through the notion of ambiguity in the predicted block match. Those blocks whose matching cost function shows too great an ambiguity in the neighborhood of the best match are instead estimated by the conventional full search. While performance of the algorithm is dependent on sequence content, it offers an attractive choice in the computational cost/performance tradeoff for simple motion compensation.