Yet a faster motion estimation algorithm with directional search strategies

An efficient fast search motion estimation algorithm is highly desired in many video coding applications. Most previous fast algorithms are performed in a blind way, without critically making use of the characteristics of motion information of the sequence being coded. In this paper, we propose a new fast search motion estimation algorithm, which uses the directional information of the selected checking points obtained in the search procedure to guide the search. The statistical information which features the motion activities of the blocks in the previous frame is used to predict the characteristics of the motion activities of the blocks in the current frame. This is to save the computational cost and to avoid spending effort on the blocks which will unlikely provide the optimal match. Hence, the computational resource can be re-assigned to locations that deserve to be searched more than others. Extensive experimental work has been done, results of which show that our approach gives a speedup of 5.39 to 1.14 times over that of the recent fast algorithms and 150 times over the exhaustive full search algorithm on average, with a negligible degradation in peak signalto-noise ratio (PSNR).