Dynamic Pattern Search Algorithm with Zero Motion Prejudgment for Fast Motion Estimation

Abstract

In the development of fast block based motion estimation (BME) algorithms, the focus is always on reduction of computational burden with quality as good as that of Full Search algorithm. Various fixed search BME algorithms like TSS, DS etc. Have been proposed in the literature for fast motion estimation but these suffer from over or under search for slow or fast motion video sequences. For quick determination of motion vector of fast moving blocks large search patterns would be helpful but this may cause unnecessary searches for small motion. Therefore a Dynamic Pattern Search algorithm had been suggested that uses the spatial coherence of the left adjacent block and temporal coherence of the collocated block from the reference frame to adjust the search pattern size. Further it was found that large numbers of blocks especially in slow motion sequences are zero motion blocks. Their early determination enhances the speed of motion estimation. A dynamic zero threshold determination model is implemented in this paper to speed up the motion estimation in Dynamic Pattern Search Algorithm. Simulation results clearly indicates 70-95% speed gain for slow motion sequences.