Enhanced block motion estimation based on distortion-directional search patterns

An improved algorithm for integer pel motion estimation based on the block matching algorithm (BMA) is presented for use in a block-based video coding system. To achieve enhanced motion estimation performance, we propose an adaptive search pattern length for each iteration of the current macro block (MB). In addition, search patterns that must be checked are determined using directional information based on the assumption of a unimodal distortion surface, thus reducing intermediate searches. This concept can be generalized to other search pattern algorithms, such as the diamond search (DS) and the three-step search (TSS). The proposed algorithm is tested with several sequences and excellent performance is verified.