Comparative analysis of occlusion-filling techniques in depth image-based rendering for 3D videos

Due to the recent success of 3D cinema, 3D video has been gathering considerable interest and delivery of 3D video to home TVs and mobile devices has been actively researched. A broadcast-friendly 3D video delivery format is so-called'view plus depth', where single video sequence is augmented by dense depth information. Based on it, desired views can be synthesized at the receiver side. While well susceptible for effective compression, this representation presents problems related with occluded areas which become visible in the synthesized views. Different occlusion filling techniques have been developed varying in quality and complexity. This contribution aims at providing an objective and subjective comparison of three such techniques. These include adaptive pre-filtering of depth maps, and one simplified and one high-performance inpainting techniques. The latter two have been specifically modified for the case of occlusion filling. We have aimed especially at ranking the performance in the case of mobile 3D imaging. Along with objective comparisons, results from subjective tests are presented as well. Both groups of results demonstrate the superiority of the second inpainting technique, which is however also the most computationally expensive one.