Image quality vs rate optimized coding of warps for view synthesis in 3D video applications

In this paper, a method for efficient warp coding is presented. Coded warps are transmitted together with stereo or multi-view video to enable additional functionalities at the receiver-side through image-domain-warping, e.g. depth adaption for stereo displays or support of multi-view autostereoscopic displays. Warp coding is performed by partitioning warps using a resolution pyramid and predictively exploiting intra and inter partition dependencies. View synthesis is employed within the coding loop to control the overall coding process, i.e. to evaluate the contribution of coded partitions to the synthesis quality. It is shown that coded warps represent a practically negligible portion of about 3.6% of the overall (video+warp) bit rate. Furthermore, it is shown that a transmission of warps leads to a reduction of synthesis time up to a factor of 8 in comparison to a fully automatic receiver-side view synthesis which uses only decoded video as input.