Underwater 3D Reconstruction Using Light Fields.

Underwater 3D reconstruction is challenging due to the refraction of light at the water-air interface (most electronic devices cannot be directly submerged in water). In this paper, we present an underwater 3D reconstruction solution using light field cameras. We first develop a light field camera calibration algorithm that simultaneously estimates the camera parameters and the geometry of the water-air interface. We then design a novel depth estimation algorithm for 3D reconstruction. Specifically, we match correspondences on curved epipolar lines caused by water refraction. We also observe that the view-dependent specular reflection is very weak in the underwater environment, resulting the angularly sampled rays in light field has uniform intensity. We therefore propose an angular uniformity constraint for depth optimization. We also develop a fast algorithm for locating the angular patches in presence of non-linear light paths. Extensive synthetic and real experiments demonstrate that our method can perform underwater 3D reconstruction with high accuracy.