New fast-search algorithm for block matching motion estimation using temporal and spatial correlation of motion vector

Abstract

This paper introduces a new technique that reduces the search time and improves the motion estimation accuracy by using the high temporal and spatial correlation of a motion vector. Instead of using a fixed first-search point, as in previous search algorithms, the proposed method identifies a more accurate first search point through compensating the search area based on the temporal and spatial correlation of a motion vector. Accordingly, the proposed algorithm is based on the consistent directivity and center-biased distribution property of a motion vector. As a result, the performance of the motion estimation is improved and the total number of search points used to find the motion vector of the current block is significantly reduced. Simulation results showed that the PSNR values improved up to 3.6 dB, depending on the image sequence, and advanced on average by about 1.7 dB. The comparative results demonstrated that the performance of the proposed algorithm was better than those of other fast-search algorithms whether the image sequence contained fast or slow motion, and similar to the performance of a full-search (FS) algorithm. Furthermore, the performance of the proposed scheme produced a superior subjective picture quality compared with other fast-search algorithms.