关键词: 运动估计, 块匹配, 菱形搜索算法（DS）, 四步搜索算法（4SS）, 差分, 视频处理, 匹配误差

Abstract: By researching into the redundancy in the Diamond Search algorithm（DS）, a new improved Difference Based Search（DBS） algorithm is proposed. By making use of the relationship between distortions of search points, the direction that leads to global minimum distortion point is predicted. In this way, the number of points which needs to be calculated is reduced. Experiment results show that the new algorithm achieves higher coding speed while maintaining the matching precision.

Key words: motion estimation, block matching, Diamond Search（DS）, Four Step Search（4SS）, difference, video processing, matching error