运动估计中的一种前处理算法

为降低视频编码中运动估计的算法复杂度,提出一种针对运动估计的前处理算法.该算法首先通过前两帧来对当前帧的矢量分布进行预测,并对大概率的运动矢量进行优先估计,使得一部分宏块的运动估计工作在前处理过程中完成,并且这些宏块的运动矢量需要的搜索点数仅为一次,因而该算法显著地提高运动估计的效率.理论分析结果表明,算法针对视频序列中的运动矢量中心偏置分布特性非常有效.把该算法分别应用于三步搜索(TSS)以及菱形搜索(DS)等算法中的实验结果表明,本算法在保持与以上算法相当的绝对误差的条件下能够大幅度降低平均搜索点数,使得运动估计的计算复杂度有了显著的降低,从而进一步降低整个视频编码的计算复杂度.

Fast motion estimation from pre- processing algorithm

To reduce the computational complexity of motion estimation for video coding,a pre-processing algorithm for fast motion estimation was proposed.The algorithm firstly predicts the motion vectors distributions of current frame from their previous ones.Then the motion vectors with big distribution probabilities are pre-estimated.After the pre-processing step,a number of macro blocks' motion vectors have been estimated and only one searching point for these macro blocks is required.Thereby,the average number of searching points is reduced greatly.We give the theoretical analysis of the algorithm,which shows that it is extremely effective for the center-biased motion vectors distribution in most video sequences.In the experiments,the algorithm was applied in two classic algorithms: Three Step Search(TSS),and Diamond search(DS) algorithm.The results show that it can greatly reduce the average searching points,while retaining comparative sum of absolute difference(SAD) with those of TSS and DS.Therefore,it can greatly reduce the computational complexity of motion estimation,as well as the overall computational complexity for video coding.