A globally adaptive pixel-decimation algorithm for block-motion estimation

For the estimation of block-motion vectors, common techniques use uniform pixel-decimation patterns to select pixels to evaluate block-matching criterion, while other techniques use adaptive pixel patterns and have achieved better efficiency. However, these adaptive techniques still require an initial division of a block into a set of uniform regions, and therefore, are locally adaptive in essence. Our proposed scheme, which does not fix any regions at the beginning and selects pixels only when they have the features important in determining a match, shows an improvement in performance over the existing adaptive schemes. Our results suggest the usefulness of this method in block-motion estimation for low-bit-rate video coding, particularly in video phone and video conferencing.