Abstract
Quality enhancement of free-viewpoint videos is addressed for 3D video systems that use the colour texture video plus depth map representation format. More specifically, a novel and efficient shape adaptive filter is presented for upsampling depth map videos that are of lower resolution than their colour texture counterparts. Either measurement or estimation of depth map videos can take place at lower resolution. At the same time, depth map reconstruction takes place at low resolution if reduced resolution compression techniques are utilised. The proposed design is based on the observation that significant transitions in depth intensity across depth map frames influence the overall quality of generated free-viewpoint videos. Hence, sharpness and accuracy in the free-viewpoint videos rendered using 3D geometry via depth maps, especially across object borders, are targeted. Accordingly, significant enhancement of rendered free-viewpoint video quality is obtained when the proposed method is applied on top of MPEG spatial scalability filters.