基于块匹配的运动向量估计算法已被多种国际视频编码标准所采用,但其计算复杂度一直是一个研究热点。为了提高运动向量估计算法的速度和精度,提出了一种新的基于概率矩阵的快速块匹配运动估计算法,该算法首先根据之前宏块的运动向量来估计当前宏块各可能的运动向量对应的概率值,以组成和搜索窗口同样大小的概率矩阵,然后依据概率大小限制搜索的次数,以平衡算法的速度和精度。仿真实验结果表明,和标准菱形搜索法相比,该算法在精度略有提高的同时,还有效地提高了搜索效率。

The complexity of video encoders in the international standards of H.263,MPEG- 4,H.264,depends mainly on the block motion estimation algorithm.In order to make motion estimation algorithm faster and more accurate,a fast motion estimation algorithm based on probability matrix is proposed in the paper.In the algorithm,every possible motion vector's probability of current macro block is estimated by the previous macro blocks' motion vectors,and constitutes the probability matrix whose size is as the same as the search window's.The algorithm restricts the number of pixels to search by probability.From the results of experiment,comparing the proposed algorithm and diamond search algorithm,it shows that the veracity is improved a little,and the speed grown faster at the same time.