A Universal Approach for Geometric Modelling in Underwater Stereo Image Processing

Most standard procedures of stereo image processing are not applicable in under underwater 3D measurement tasks. Due to refraction, the collinearity of an image point on the sensor, the camera projection centre and the 3D object point is not fulfilled. This paper presents a universal model to strictly handle refraction effects on one or multiple interfaces between different media. The proposed model can be easily integrated into standard procedures such as photogrammetric bundle adjustment. It allows for the simultaneous determination of all parameters in a camera network setup, including the camera interior and exterior orientation parameters, the coordinates of 3D object points, refraction indices as well as interface surface parameters. Practical experiments prove the correctness of the implemented model and show hat a high level of accuracy can be achieved.