A New Fast Block Motion Algorithm Based on Octagon and Triangle Search Patterns for H.264/AVC

The block motion estimation process is an integral and important part in the current video coding standards. However, the current algorithms for the block motion estimation process either have a large computational complexity, or have a poor accuracy. The UMHexagonS algorithm is recommended for the implementation of H.264 for its relatively good performance. In this paper, a new fast block motion estimation algorithm is proposed, which reduces the computational complexity of the UMHexagonS algorithm by more than 33 percent and have about the same accuracy. This is achieved by first classifying the motion type of a block. Then, for the block with regular and small motion, two newly proposed efficient search patterns, the octagon search pattern and the triangle search pattern, are, respectively and recursively, utilized to find a good motion vector by using low computational complexity. For the block with irregular or large motion, a symmetrical cross search pattern is first used, followed by the multi-octagon-grid search pattern due to its low complexity and good search efficiency, and finally the large diamond and triangle search pattern are, respectively and recursively utilized to refine the search process and obtain a motion vector with good accuracy.