Monocular underwater stereo - 3D measurement using difference of appearance depending on optical paths

Sensing in aquatic environments meets the difficulty that, when a camera is set in air behind a watertight glass plate, image distortion occurs by refraction of light at the boundary surface between air and water. This paper proposes an aquatic sensing method to execute three dimensional measurement of objects in water by taking refraction of light into account. The proposed method is based on a monocular stereo technique using a difference of appearance depending on optical paths. Optimization of the angles of refracting surfaces which are key elements of the sensing device is given to realize the accurate measurement. Experimental results show the effectiveness of the proposed method.