1. Introduction
Over the past few years, light field (LF) has gradually developed into one of the mainstream research areas of computer vision. Benefiting from the potential capability of additional directional information, LF simultaneously records both spatial information and angular information of all light rays. In addition, with the advent of plenoptic cameras, LF acquisition is greatly simplified and can be obtained in a single shot. Therefore, a large variety of research fields try to use LF instead of single image or video sequence for superior performance by mining internal structural information.