Edges shape enforcement for visual enhancement of depth image based rendering

Depth image based rendering of intermediate views with high visual quality remains a challenging goal in presence of estimated and quantized depth values. Among the other rendering artifacts we observed that edges are usually affected by significant warping errors. In particular, because of depth estimation inaccuracy around object boundaries the edges may completely loose their original shape during the warping process. Nonetheless, edges represent one of the most important cues for the human visual system. In this paper a novel technique aiming at improving the edge rendering is presented. As opposed to previous approaches, the technique exploits only texture information, thus avoiding possible errors in depth estimation. The idea is based on the enforcement of prior knowledge of the edge shape under projective transformation. The proposed algorithm works in two steps: first the damaged edges of the warped image are detected, then these latter are corrected so as to better approximate their shape in the reference view. Finally the corrected edges are rendered within the intermediate image without introducing noticeable texture artifacts. The proposed algorithm has been tested on a variety of standard video sequences exhibiting excellent results in terms of rendered image visual quality.