| As the development of computer, communication and network technology, real-time 2D video visual communication has become mature, and all video products have already entered into our lift, study and work, and so on. However, with the requirements of high definition and realistic video quality, traditional 2D video is no longer entirely satisfying the requirements. Free viewpoint video allows the users to change his/her viewing point and viewing direction freely and enjoy more photorealistic 3D images. With these functions, free viewpoint video will have good application in remote education, remote control, virtual reality system, and so on. Therefore, as current research hotspot, free viewpoint video technologies have attracted increasing researcher inside and outside country.In this paper, key technologies are studied from perspective of constructing free viewpoint video system. Firstly, because free viewpoint video is captured by multi-camera system, the data amount is several times of general video. In chapter 4 free viewpoint video coding technologies are researched. In second section, based on the analyzing of ray-space data correlation and data characteristic, fast adaptive block matching and rectilinear direction search data compression algorithms are proposed. Experimental results show the proposed algorithms can improve coding efficiency obviously compared with only inter-slice correlation based coding methods. This is one contribution of the thesis. Then in third section, 3DAV multi-view video coding schemes are compared in compression efficiency, computation complexity, memory consumption, random access and so on.Next, because of scene illumination, camera calibration, CCD noise, the color difference between different viewpoints may be very large, which brings much difficulty to the following processing. In chapter 5, multi-view video color correction technologies are researched. The basic correction steps are as follows: Color mapping relations are first constructed based on color information from different viewpoints, and then image is corrected based on the mapping. Global, region or pixel informations can all be use to construct the mapping. A series of algorithms are proposed in this paper. Correction parameter adjusting algorithm constructs pixel mapping relations through dynamic region segmentation. Region segmentation and tracking based algorithm constructs one dimension linear mapping relation based on region matching, and then implement video correction by region tracking. Principal componet analysis based automatic correction algorithm constructs three dimensions linear mapping relations based on principal component analysis, also implement video correction based on principal component tracking. Correction in noise cast is also discussed. Dynamic programming based nonlinear correction algorithm constructs best mapping route by dynamic programming, also implement video correction based on route tracking. Experiment results show the algorithms can reach well correction result for certain color change case. This is another contribution of the thesis.Next, in order to further combine color correction with data compression or virtual viewpoint rendering, multi-view luminance compensation and vector disparity based multi-view video color correction and virtual viewpoint rendering method are proposed in chapter 6. High coding efficiency and well rendering quality are realized as well as color correction. This is another contribution of the thesis.Finally, in section 6, three system frameworks are proposed combined with three key technologies. Experimental simulation is performed for one system.
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