UMHexagonS算法的优化研究

Research and Optimization of UMHexagonS Algorithm

视频编码标准H．264已经正式采纳了UMHexagonS算法作为整像素的快速运动估计算法。文章对UMHexagonS算法进行了介绍，对其特点进行详尽分析后，提出了一种改进方法，即在预测起点处增加一个内容自适应的中止搜索阈值判断，以判断是否可立即结束搜索。模拟实验表明，相比原算法，在基本保持了原算法的的编码效果，还明显减少了搜索点减少了运动量，从而节省了编码时间。

The video coding standards H.264 have adopted Unsymmetrical cross Multi Hexagon grid Search （UMHexagonS） algorithm for integer pels motion estimation. However, further investigation on fast motion estimation method is still necessary. In this paper, based on the study of the principles of the UMHexagonS algorithm, an improved method is proposed, in which the idea of a new adaptive factor is introduced in initial search point prediction step for early termination. Simulation Results show that the improved UMHexagonS algorithm can reduce search points with minimal loss in bit-rate and reconstructed quality compared with those of the original UMHexagonS algorithm.