| With the progress of society and the rapid development of science and technology, the application of video image technology is used more and more widely.Multiple high definition TV and multimedia products exist on the market nowdays. The variety of players need different video sources and the current existing video sources far satisfy the demands of these products. Hence we need frame rate up conversion technology in these products.It is a video processing technology which improves the low frame rate of video sources by using frame interpolation. For example, we need to change the film source from 24 frames per second up to 60 frames per second. Then it can be smoothly broadcast in a variety of high clear digital TV and broadcast equipment.At present, video calling becomes more and more popular. During the transmission process,it is usually low frame rate transmission. The main reason is to reduce transmission bandwidth.However, the video receiver must restore the frame rate and therefore frame rate up conversion technology is used. At the same time, it can reduce the video frequency and stagnation phenomenon in the process of watching video and people can get a better visual enjoyment.At present, the more popular frame rate up conversion technology is motion compensation. It do frame interpolation by estimating object motion information. Motion compensation has two parts: motion estimation and motion compensation.In this paper,we do research on the advantages and disadvantages of the commonly used motion estimation algorithms such as three step search method and the traditional 3-D recursive search(3DRS) algorithm. The results show that they can not get effective and smooth vector field. Then the image of the motion compensation is fuzzy and shadowy.we get the idea of multi-layer block matching combined with the traditional 3DRS algorithm. Then a hierarchical block matching motion estimation algorithm based on 3DRS is proposed. The proposed algorithm divide one image into layers. The 3DRS algorithm is used on each layer.At the same time, the traditional 3DRS algorithm can not choose good candidate vectors for the fixed scan sequence.Then we add a variety of 3DRS search method. It can choose more appropriate reference vectors and then get more accurate vector field. In order to speed up our algorithm and get more accurate vectors,we add withdraw strategy. In the end, when the motion vector field is obtained, we do vector field smooth and the smoothness of the vectors is ensured.Experimental results show that the algorithm has a great improvement from the objective and subjective aspects when compared with the traditional 3DRS algorithm and the three step search method.In this paper, a motion compensated interpolation algorithm with weighted coefficients is adopted to compensate the overlap, block effect and holes caused by one-way motion compensation. The weighted coefficients are determined by calculating absolute error of overlapping areas coefficients of the forward and backward frame interpolation and forward or backward reference frames. Experimental results show that the proposed algorithm is improved in both objective and subjective aspects compared with linear interpolation algorithms. It is also a good solution to solve the problem of overlap,block effect and hole of one-way motion compensation. |
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