Research On Motion Estimation Based On H.264/AVC

H.264/AVC (Advanced Video Coding) is a new generation video compression coding standard and a hotspot in the current image communication field, which was established by the ITU-T Video Coding Experts Group and the ISO/IEC Moving Picture Experts Group.H.264/AVC has achieved a significant improvement in compression performance and a"network-friendly"video representation relative. Motion estimation is one of the core technologies of video compression coding, but also the most time-consuming module. At present, the research on looking for a fast and effective motion estimation algorithm that can get an accurate motion vector becomes a hot topic.In this paper, the international video encode standards and their principles were discussed.Then, it introduces the stream syntax structure of to grasp the coding framework as a whole; and studyed its key technology in-depth. After the research on the block-matching motion estimation algorithms, this paper analysised and compared several classic search algorithms. In conclusion, it proposed a novel motion vector adaptive search algorithm (DPMV).In DPMV,the type of local motion activity and initial search center is first determined according to the motion vector field, then different search algorithm are adaptively used according to the motion activity of current macroblock. Experimental results showed that DPMV could obtain good PSNR performance as well as low computation cost. With the new core technologies of H.264/AVC, an efficient fast fractional pixel motion estimation algorithm (QAFSA) is proposed based on that the distortion of a search point monotonously increases with increasing distance from that search point to the global minimum point, and the center-biased of motion vector. Test results showed that the proposed algorithm reduces the number of searching points greatly and consumed less computation time, while keeping the nearly equal quality of the image and the bit rate.The simulation results suggest that both of the search algorithms can greatly increase the calculating speed of H.264/AVC coder, which is helpful for real time applications.