运动估值的快速算法普遍存在着精度过低的缺陷。本文应用块匹配法的基本原理，通过对块匹配规律的分析，找到了改进对偶法快速算法搜索路径的有效方法，提出了实用快速算法——最大梯度及多重循环对偶法。该算法在兼顾准确性的同时，保留了算法路径简单、易于实现的优点，其匹配结果仍具有快速算法的速度且更加接近全匹配算法的精度。

Generally fast algorithms for motion estimation have low precision. Based on the basic theory and rule of block matching, a new fast motion estimation algorithm which uses maximum grads and more cycle conjugate search algorithm to improve searching approach, is presented. Its speed is comparable to typical fast algorithm and its precision is compariable to the exhaustive searching algorithm, meanwhile it has veracity, simple algorithm path and is easy to be realized. The results of the comparison are also presented.