Predictive depth map coding for efficient virtual view synthesis

This paper presents a novel approach to compress depth maps envisioned for virtual view synthesis. This proposal uses a sophisticated prediction model, combining the HEVC intra prediction modes with a flexible partitioning scheme. It exhaustively evaluates the prediction modes for a large amount of block sizes, in order to find the minimum coding cost for each depth map block. Unlike HEVC, no transform is used, the residue being trivially encoded through the transmission of just its mean value. The experimental results show that, when the encoding evaluation metric is the quality of the view synthesized using the encoded depth map against the map encoding rate, the proposed algorithm generates reconstructed depth maps that provide, for most bitrates, some of the best performances among state-of-the-art depth maps encoders. In addition, it runs approximately as fast as the HEVC HM.