Multi-Layer Flat Refractive Underwater Camera Calibration for Visual SLAM

Most underwater camera calibration methods only consider the refraction of light in the water and ignore the effect of glass. During the calibration process, the angle between the imaging plane and the refraction plane was ignored, which inevitably generates calibration errors. To address this problem, a new underwater camera model is proposed, which rotates the camera by taking into account the refraction of light among different media. The imaging plane of the camera after rotation is parallel to the refractive surface. According to the refraction of light between different adjacent media, the camera model we derived shows that the intrinsic of the camera under different media only differs by a scale factor. Finally, an experimental platform is established to verify the correctness of our theoretical derivation.