Virtual Viewpoint Rendering Technology Based On Disparity Estimation And Correction

With the development of 3 D display technology,3 D television (3 DTV) system is improved gradually, and the next goal should be Free-Viewpoint display. In the Free-Viewpoint display system, spectators can arbitrarily switch their viewpoint as they wanted, and then the Free-Viewpoint display system would have a better user experience. However, it is impossible for us to get any viewpoint of the scene with an unlimited number of cameras. The virtual viewpoint rendering technology is mainly being used at present. It could produce other perspective image by using the limited viewpoint of the scene. But, there are many problems to be solved about virtual viewpoint of rendering technology at present. Therefore, an effective and reasonable virtual viewpoint rendering technology is a hot spot in the research of the three-dimensional display currently.The research is mainly to deal with the problem of DIBR in the virtual viewpoint rendering technology in this thesis, including the error caused by the discontinuity of the scene and texture regions in the process of getting the depth map, ghosting and uncoordinated phenomenon in the process of hole filling in virtual viewpoint rendering technology.The main content of the thesis includes the following parts:To deal with the problem of the low texture region and disparity discontinuity in stereo matching, A disparity estimation algorithm based on variable window method is presented, this method is to use a larger window matching to choose high reliability of points, then spread reliable matching point to the whole area by segmentation smooth constraint conditions, thus, improve the integral disparity estimation accuracy, compared with the traditional adaptive matching algorithm, this algorithm is about ten percent lower than the traditional adaptive matching algorithm in disparity discontinuity region.Second, convert stereo matching of parallax figure into depth map to virtual viewpoint rendering,for the problem among two-way virtual rendering technology to fill the hole, which caused by the error of depth map, the hole filling of depth error correction is proposed in this thesis, firstly, the hole neighborhood of the reference image and the target image is extract after 3d warping, offset value of minimum cost is got by using SAD algorithm. Then adjust the target image according to the offset value, thus, it could improve the accuracy of hole filling.Finally, to deal with the problem of artifacts and inharmonious phenomenon in two-way virtual viewpoint rendering, this dissertation using a linear fusion technology, the method is to fuse the hole neighborhood. After target image is corrected by SAD algorithm, the reference image and target image are merged according to the reliability of the neighborhood pixels, therefore, this method will not appear ghost phenomenon, and it can reduce the artifacts and inharmonious. Compared with the traditional two-way DIBR algorithm, PSNR of the method improves 0.77 dB.Virtual viewpoint rendering technology is the key part of the free stereo display system. This thesis aimed at analyzing and processing the problems existing in the traditional DIBR algorithm. Both on the subjective and objective evaluation have certain improvement.