Depth Map Intra Coding Based on Virtual View Rendering Distortion Estimation

Since compressing depth map using existing video coding techniques yields unacceptable distortions while rendering virtual views, the depth maps need to be compressed in a way that it minimizes distortions in the rendered views. A distortion model is proposed that approximates rendering distortions caused by depth changes on depth coding. First, relationships between distortions in coded depth map and rendered view are derived. Then, a region based video characteristics distortion model is proposed for precisely estimation distortion in view synthesis. Finally, the new distortion metric is used to select encoding mode decisions for Rate Distortion (RD) optimization, while reducing rendering distortions. Simulation results illustrate that proposed techniques improve the objective quality of the rendered virtual views by up to 2 dB over the Lagrange Optimization based mode selection technique that considers the distortions only in the depth map.