Abstract: The diamond search (DS) algorithm has been adopted by MPEG4 standard, and
currently recognized as a better search algorithm. But the speed of DS algorithm is slow when the
motion vector is small. The improved diamond search (IDS) algorithm is presented. Rough
location and enhanced halfway-stop operation are added to it. Lots of vehicle tracking
experiments show that the IDS algorithm improves the search speed on the basic of ensuring the
search performance, supplying more effective technique support for template matching. Moreover,
contrastive experiments prove the algorithm is insensitive to mutational trajectory.

Key words: improved diamond search algorithm, motion vector, rough location, enhanced
halfway-stop operation