Motion estimation with low resolution distortion metric

Considering all possible candidate motion vectors in a given search area and calculating a distortion measure at every search position, as with the full-search block-matching motion estimation algorithm (FSBME), places a prohibitively high computational burden on the video encoder, making it unsuitable for real-time/portable video applications. To reduce computational complexity while maintaining accuracy, a new version of the reduced-bit, sum of absolute difference (RBSAD) algorithm is presented, which allows for optional correction to full resolution (FSBME) when appropriate. Analysis of a number of video sequence shows that this correction is required for blocks for which there is little motion between frames.