A Modified Diamond Search algorithm

DS (Diamond Search) is one of the most famous motion estimation algorithms. By analyzing the characteristics of DS, it is found that DS can be improved more efficiently. A Modified Diamond Search (MDS) algorithm is proposed in this paper. Firstly, MDS employs Small Diamond Search Pattern(SDSP) to judge if the MBD(Minimum Block Distortion) point is the initial search center. If the MBD point does not locate at the search center, Simplified Large Diamond Search Pattern(SLDSP) will be used in the next search step. If the MBD point is not within the circular area with a radius of one pixel, SLDSP will be employed continually to locate the best matching block with large motion vector until the search center become the MBD point. Finally SDSP will be adopted to refine the motion vector. Experimental results show that MDS can speed up the motion estimation process greatly under the same encoding efficiency compared to DS, especially for those video sequences with simple and slow motion vectors.