Inherently edge-preserving depth-map coding without explicit edge detection and approximation

In emerging 3D video coding, depth has significant importancein view synthesis, scene analysis, and 3D object reconstruction.Depth images can be characterized by sharpedges and smooth large regions. Most of the existing depthcoding techniques use intra-coding mode and try to preserveedges explicitly with approximated edge modelling. However,edges can be implicitly preserved as long as transformationis avoided. In this paper, we have demonstrated thatinherent edge preserving encoding of inter-coded block residuals,uniformly quantized at pixel domain using motion datafrom associated texture components, is more efficient than explicitlyedge preserving intra-coding techniques. Experimentalresults show that the proposed technique has achieved superiorimage quality of synthesized views against the new 3DHEVCstandard for depth-map bit-rate 0.025 bpp or higher.Lossless applications of the proposed technique has achievedon average 66% and 23% bit-rate savings against 3D-HEVCwith negligible quantization and perceptually unnoticeableview synthesis, respectively.