块匹配运动估计在视频编码中有着举足轻重的地位,其性能的优劣在很大程度上影响着输出码流的质量。全搜索是效果最好的运动估计算法,但其巨大的运算量是实际应用无法承受的。为解决这一问题,该文提出了一种基于H.264自适应块搜索范围快速运动估计算法。该算法是利用相邻宏块的运动矢量来确定初始搜索中心位置,并动态地确定搜索区域的大小。与以往固定搜索区域的算法相比,它具有更高的灵活性,还可以与其他任何一种快速运动估计算法相结合。仿真结果表明,在基本不损失性噪比的前提下,根据不同的运动序列,该算法可不同程度地减少运算的复杂度。

Block matching motion estimation(BMME) plays a very important role in video coding.The performance of BMME greatly affects the quality of the encoded bit stream.Full Search(FS) is the optimal algorithm for BMME.But its tremendous computation payload is unaffordable for practical applications,especially for real-time applications.To overcome this problem,a lot of fast algorithms were developed.This paper presents an adaptive fast motion-estimation algorithm based on H.264.Taking advantage of motion-vectors of the nearby macro-blocks to find the original searching central position and determine the size of the searching zone.Compared with the former algorithms with fixed searching zone,this algorithm is more flexible and can combine with any other fast motion estimation algorithm.Experimeotal results show that the algorithm can reduce computation amount variously by different motion-sequence under the premise don't reduce the PNSR.