一种H.264/AVC中的快速运动估计算法

在UMHexagonS算法的基础上，最新的H.264/AVC视频编码采用一种简单、有效的混合快速运动估计算法。该文介绍一种新的快速搜索算法，初步研究和分析其综合性能的优越性，并提出改进策略，如增加终止搜索的判定、进一步划分运动类型、采用自适应的方向性搜索模板。实验结果表明，改进的策略能减少“简化UMHexagonS算法”8%~30%的搜索时间，而码率和率失真性能的变化可以忽略不计，对一些特殊序列，率失真性能略优于“简化UMHexagonS算法”。

Fast Motion Estimation Algorithm in H.264/AVC

The latest video coding standard proposes a simple yet efficient hybrid FME scheme based on the existing UMHexagonS scheme. This paper introduces this new fast search algorithm. Some improved schemes are proposed based on the study and analysis of the advantages of simplified UMHexagonS algorithm, such as introduces more early terminate criterions, further division to the motion type, adoptes directional search patterns for different blocktype adaptively, etc. Experimental results show that the improved strategies can reduce about 8%~10% of motion estimation time, while the R-D performance and bit rate are almost the same as simplified UMHexagonS algorithm.