Abstract: Motion estimation algorithm is the research priority of video encoding technology. High precision and high efficiency of the match and compensation can reduce prediction error and improve video compression effect, so the accuracy of block matching is the core issue. The Minimum Absolute Difference(MAD )，the Minimum mean Square Error (MSE) , Normalized Cross}orrelation Function (NCCF)，the classification of pixel difference, sulrsampling, Variance Of Difference ( VOD) , and other matching criterions were theoretically and experimentally analysised. And a method of using the distribution of the image difference as a matching criterion was proposed, that is image Difference Variance (DVAR) matching criterion. Experimental results show that image difference variance matching criterion received relatively high codec quality. Finally the paper pointed out the future development of block matching criterion which is more in line with the human visual system (HVS) characteristics.

Key words: Motion estimation, Matching criterion, Block matching, Mean square deviation, Structural similarity(SSIM)