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Studies On Lapped Orthogonal Transform And Video Segmentation And Coding

Posted on:2004-08-16Degree:DoctorType:Dissertation
Country:ChinaCandidate:L Y BiFull Text:PDF
GTID:1118360185964875Subject:Communication and Information System
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The main focus of this dissertation is on development of video technology, and divided into two part: one part is about the research of the improvement of first generation video technology. A detail analysis for the lapped orthogonal transform is made, and its extended transform is applied in the video coding; meanwhile, other part is about the key technology of second generation video technology-video object segmentation and coding.The main focus of first part is on the research about the lapped orthogonal transform, which could reduce block effect of image coding. The main work of this part is as follows:1. The detail analysis of lapped orthogonal transform, which can reduce block effect, is presented. Theory analysis of lapped orthogonal transform is given, and the experiment is done. The experimental results show this method could give better coding efficiency than the traditional DCT image coding.2.Improved complex lapped transform domain motion estimation is presented. A method for estimating phase correlation in complex lapped transform is derived, which form the basis of a motion estimation algorithm that calculate vectors from the corresponding overlapped window region of image, so a global optimal of motion vector is easily got. Based on overlapped smooth window characteristic of complex lapped transform, the method could decrease the discontinuity of block edge, and thus produce a smooth motion field, which may reduce bit stream for motion vector. The experimental results demonstrate this method is better than other fast block-matching methods, produce good performance similar to full-search methods. This method produce smoother motion field, reduce bit stream of motion vector, and have a low computational complexity.3.To deal with the characteristic of disparity estimation, a hierarchical complex overlapped transform domain disparity estimation is presented, first, a fast algorithm of complex lapped transform is derived, and a disparity estimation based on complex lapped transform domain phase correlation is done in hierarchical structure.. The method processes a global optimal motion estimation in overlapped window region, and use the hierarchical structure to overcome the disadvantages of fixed size block matching, so have a correct disparity vector, and produce a smoother disparity map. The experimental result show this method could decrease the computation...
Keywords/Search Tags:lapped orthogonal transform, video object, complex lapped transform, color image segmentation, shape-adaptive wavelet coder
PDF Full Text Request
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