Non-regular homogenous block representation for low bit rate depth coding in 3D video

Abstract

In multi-view video plus depth (MVD) format based 3D video (3DV) systems, the quality of the rendered virtual views depends highly on the quality of the compressed depth maps. Therefore, depth coding technology is vital for 3DV applications. This paper proposed a superpixel based non-regular homogenous block (NRHB) representation for low bit rate depth map coding. At the encoder side, with the aid of the superpixel segmentation of the associated texture images and the synthesis distortion estimation of the virtual views, the original depth maps are partitioned into several NRHBs and represented with only a small amount of pixels. Then, the NRHB represented depth maps are compressed by using the standard video coding approach afterward. At the decoder side, the depth maps are reconstructed through position mapping of the superpixel segmentation of the decoded texture images, and enhanced by a false edge filter. The experimental results show that the proposed method could impressively increase both the coding efficiency of the depth maps and the rendering quality of the virtual views. It also can be seen that the proposed method significantly reduced the encoding computational complexity for depth maps, which makes it particularly useful for the low bandwidth mobile consumer devices with limited computational resources.