The Research Of Motion Estimation Algorithm In Video Compression

With the development and popularization of computer and network technology, video technology has been widely applied to various applications and plays a more and more important role nowadays. Among the factors which influence the coding quality and efficiency for video compression, motion estimation technology is the most important one. It is known that the accuracy of motion estimation usually determines the quality of decoded images to a great extent. However, motion estimation contributes to the most part of computational load in thewhole video coding system. Thus research on efficient motion estimation algorithm becomes a focus in video coding field.At first, this paper gives an overview of a series of international standards for video coding, then introduce the basic theory and key points of its core technology, which is block-matching motion estimation. On the basis of the analysis on popular fast block-matching algorithms, Addaptive Fast Search algorithms were proposed.Because of the high correlation of the motion vector of adjacent block, we use the motion vectors of blocks on left, top, and top-right to predict the range of motin vector of current block. According to the difference of the range of motion vector, we can use different search pattern to find the MBD point. Thus the motion estimation algorithm will be more efficient and will find the MBD point more quickly. We can get the predictive motion vector using the high correlation of the motion vector of adjacent block. It can improve the accuracy and speed of search algorithm. Based on these technologies talked about before, we propose Addaptive Fast Search algorithms.When range of motion vector is very small, we use small diamond search pattern to find the MBD point. It can improve the speed of search algorithm efficiently;When the range of motion vector is middle, we use 3×3 square pattern in our algorithm, it can improve the speed of algorithm without loss of accuracy;When the range of motion vector is big, we use DS algorithm in our search algorithm, it can improve the speed of search algorithm.Experiment shows that Addaptive Fast Search algorithm can improve the speed of search algorithm markedly without loss of accuracy.