An improved search algorithm for motion estimation using adaptive search order

An adaptive search order (ASO) algorithm is presented in this letter to spe ed up the block motion estimation in digital video coding. According to the motion trend, a table of the adaptive search order is defined. For each se arching iteration, a better search order is derived and then the best match ed block can be found in the early search stage. Some experimental results demonstrate the computational advantage of the proposed improved algorithm when compared to previous algorithms, such as the full search algorithm, th e successive elimination algorithm, the block sum pyramid algorithm, and th e multilevel successive elimination algorithm.