Disparity map coding for 3D teleconferencing applications
André Redert, Emile A. Hendriks · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1997
In this paper we present a combination of there steps to code a disparity map for 3D teleconferencing applications. First we introduce a new disparity map format, the chain map, which has a very low inherent redundancy. Additional advantages of this map are: one single bidirectional map instead 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 too, 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 to 80 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.