A constrained disparity estimation method is proposed which uses a directional regularization technique to efficiently preserve edges for stereo image coding. The proposed method smoothes disparity vectors in smooth r...
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A constrained disparity estimation method is proposed which uses a directional regularization technique to efficiently preserve edges for stereo image coding. The proposed method smoothes disparity vectors in smooth regions and preserves edges in object boundaries well, without creating an oversmoothing problem. The differential pulse code modulation (DPCM) technique for disparity map coding is used prior to entropy coding, in order to improve the overall coding efficiency. The proposed disparity estimation method can also be applied to intermediate view reconstruction. Intermediate views between a left image and a right image provide reality and natural motion parallax to multiviewers. Intermediate views are synthesized by appropriately exploiting an interpolation or an extrapolation technique according to the characteristics of each region after identifying the regions as occluded regions, normal regions, and regions having ambiguous disparities. The experimental results show that the proposed disparity estimation method gives close matches between a left image and a right image and improves coding efficiency. In addition, we can subjectively confirm that the application of our proposed intermediate view reconstruction method leads to satisfactory intermediate views from a stereo image pair.
In this paper we present a combination of three steps to code a disparitymap for 3D teleconferencing applications. First we introduce a new disparitymap format, the chain map, which has a very low inherent redundanc...
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ISBN:
(纸本)0819424358
In this paper we present a combination of three steps to code a disparitymap for 3D teleconferencing applications. First we introduce a new disparitymap format, the chain map, which has a very low inherent redundancy. Additional advantages of this map are: one single bidirectional map in stead of the usual two unidirectional vector fields, explicit indication of occlusions, no upper or lower bound on disparity values, no disparity offset, easy generation by disparity estimators and easy interpretation by image interpolators. In a second step, we apply data reduction on the chain map. The reduction is a factor two, thereby losing explicit information about the position of occlusion areas. An algorithm for image interpolation in absence of occlusion information is presented. The third step involves entropy coding, both lossless and lossy. A scheme specially suited for the chain map has been developed. Although the codec is based on a simple prediction process without motion compensation, compression ratios of 20 (lossless) to 80 (lossy) can be achieved with typical teleconferencing images. These results are comparable to those obtained by complex schemes based on 2D/3D motion compensation using disparity vector fields.
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