Underwater sensing with omni-directional stereo camera

In this paper, we propose an underwater sensing method by using an omni-directional stereo camera system. When observing objects in water through a camera contained in a waterproof housing or observing objects in an aquarium tank filled with preserving liquid, we should solve a problem of light refraction at the boundary surfaces of refractive index discontinuity which gives image distortion. The proposed method uses two omni-directional cameras that have wide field of view to measure underwater environments. A ray tracing technique solves the problem of image distortion caused by refractive index discontinuity. Experimental results show the validity of the proposed method.