Rotating coded aperture for depth from defocus

Abstract

This paper proposes a rotating coded aperture we called RCA for depth recovery, complementing the previous depth from defocus methods in both recovery accuracy and friendliness for hardware implementation. In the proposed RCA, an optimized coded aperture is rotated around the optical axis, and multiple images are taken at a few locations of the rotated aperture. We derive a criterion to evaluate the depth recovery performance of the RCA. With this criterion, the coded pattern of rotating aperture and the angles of rotations are jointly optimized by a genetic algorithm combined with a multiscale refinement strategy. The proposed RCA is demonstrated to have better depth from defocus performance over other multiple coded aperture schemes.