1. Introduction
The problems of interpolation and extrapolation have a long history in mathematics and computer science. In high-level computer vision, interpolation finds its application in various problems like motion estimation in 2D (optical flow) [1, 2, 11, 14, 15, 20, 30, 31, 33, 43, 50], 3D (scene flow) [36], [37], or depth completion [6], [17], [26], [40], [41]. These methods in turn are applied in robot navigation, advanced driver assistance systems (ADAS), surveillance, and many others.