一种改进的UMHexagonS运动估计算法

Improved UMHexagonS Motion Estimation Algorithm

在视频编码中，运动估计占据约70％的编码时间，是视频编码中的重要环节。整像素运动搜索UMHexagonS算法以较低的计算复杂度，达到了接近全搜索算法的率失真性能，而被H．264和AVS等标准所采纳。在分析UMHexagonS算法的基础上，对其非对称十字形搜索和非均匀多层次六边形格点搜索算法进行了改进。实验表明，在基本保持原算法性能的同时，该算法比原算法减少了60％～70％的搜索点数，降低了运动估计的计算复杂度。

Motion estimation is a significant part of video coding, accounting for around 70% of the computing time. Integer pixel motion search algorithm UMHexagonS achieves a performance close to full search algorithm with lower computation complexity, so is adopted by H. 264 and AVS. An improved nonsymmetrical cross search and anisotropic multilayer hexagon search method is proposed in this paper. Experiment results show that the proposed algorithm reduces search points by 60% -70% while keeping the original performance generally, so the computation complexity of motion estimation process is reduced.