Single depth map super-resolution via joint non-local and local modeling

Depth maps are widely used in 3D imaging techniques because of the appearance of the consumer depth cameras. However, the practical application of the depth map is limited by the poor image quality. In this paper, we propose a novel framework for the single depth map super-resolution via joint the local and non-local constraints simultaneously in the depth map. For the non-local constraint, we use the group-based sparse representation to explore the non-local self-similarity of the depth map. For the local constraint, we first estimate gradient images in different directions of the desired high-resolution (HR) depth map, and then build a multi-directional gradient guided regularizer using these estimated gradient images to describe depth gradients with different orientations. Finally, the two complementary regularizers are cast into a unified optimization framework to obtain the desired HR image. The experimental results show that the proposed method can achieve better depth super-resolution performance than state-of-the-art methods.