High-quality Light Field Interpolation in Epipolar Plane Image Domain by DCT-based Shearing

Light field (LF) is a 4-D function representing the light radiance in free space in terms of rays. A dense grid of cameras, parameterized by two planes, captures an LF: the sensor plane and the focal plane. Multi-camera images stack in volumes, and when sliced, form epipolar plane images (EPI). In EPI, lines with the same slope represent object points at the same scene depth. Thus, the synthesis of new views can be formulated as a problem of interpolation in EPI domain. In this contribution, we propose a three-pass algorithm for LF interpolation in EPI domain. Each EPI is sheared by a factor determined by the dominant slope, employing fast DCT-based fractional shifts. In sheared EPI, dominant lines appear vertical and can be easily interpolated. 'De-shearing' reconstructs EPI's original geometry. We analyze the performance of the proposed LF interpolation in Fourier domain and illustrate it with examples of virtual view synthesis from dense multi-camera imagery.