The Research On Motion Estimation Technique For Video Images Based On The Block-matching

The motion estimation of video images is the technology of estimating motion information of every object in the image according to the related two or more than two frames of image. Among which, the technique of motion estimation based on the block-matching is a simple method, with the good effect of estimation, the high compression efficiency and satisfying the real time calculation easily of hardware system. It was adopted by many video coding standards such as MPEG-1/2 and ITU-T H.261/263, consequently becomes a hot subject in the digital video technology.First, based on the study of the theory of the block-matching motion estimation with details, this paper summarized the classical block-matching algorithms by the numbers at home and abroad at present, analyzed the merits and demerits of each search strategy. Second, we make the search course, search direction, search step, search pattern and stop search criteria as our main discussing clue and address the dissertation on the key technique of fast motion estimation—search strategy. In the aspect of motion estimation based on the characteristics of motion vector distribution, we introduced the distributing trait of center–biased of motion vector and the distributing trait of deflection of motion vector, described the relation between these two distributing traits of motion vector. The conclusion we got is that the discovery of deflective distributing trait of motion vector is not a denial to center-biased distributing trait of motion vector. Motion vector is first in the basis of central distribution then with the deflective distribution, deflective distribution is within the central distribution. Therefore, the distributing trait of deflection of motion vector is the most accurate complementarity to the distributing trait of center–biased of motion vector, that is the basis of this paper. In the end, based on the completely analyzed and concluded the study of block-matching technique, taken fully advantage of the distributing trait of deflection of motion vector and the distributing trait of center–biased of motion vector, we proposed two block-matching algorithms based on the distributing trait of motion vector, i.e. the block-matching algorithm based on small diamond template and the block-matching algorithm based on mixed template. Experimental results show that these new methods hold the advantage in reducing the complexity of calculation and improving the accuracy of motion estimation and so forth.