Depth map super-resolution based on edge-guided joint trilateral upsampling

Depth image super-resolution (DISR) is a significant yet challenging task. In this paper, we propose a novel edge-guided framework for color-guided DISR aiming at reducing the artifacts caused by the introduced color image. Considering the different view synthesis characteristics of texture and smooth regions in depth image, we propose that the edge and smooth regions of depth map should be reconstructed in different ways. In our framework, a novel joint trilateral filter is built firstly, which has two different modes: one for the pixels on the edges and the other for the pixels in the smooth regions. Secondly, in each filtering iteration during the whole upsampling process, we use the edge map updated by the upsampled depth map as a guidance to decide when to change the filter mode. Benefiting from the strategy, the high-resolution depth map reconstructed has less texture copying and contains sharp and smooth edges. Experimental results demonstrate the effectiveness of our approach over prior depth map upsampling works.