The Three-Dimensional Measurement Of Underwater Objects In Paracatadioptric Camera

The technology of 3D reconstruction in water is an important application in the field of computer vision. The pinhole camera has limited imaging angle, while the parabolic catadioptric camera can provide a very wide field of view, which is more suitable for wide-angle 3D reconstruction. Using the parabolic catadioptric camera model, according to the law of refraction, this thesis establishes the projection model of object in water under the parabolic catadioptric camera, then restores the external parameters of the camera and the location interface parameters of the refraction interface, and through the establishment of the error function optimizes camera's external parameters. Finally calculates the three-dimensional coordinates of the object in water using the optimized parameters and the location parameters, and the validity of this method is verified by simulation data and real experiments. The main contents are as follows:(1) Based on the unit sphere model of parabolic catadioptric camera, through the analysis of the refraction of light in the water, establishes the projection model of object of water under the parabolic catadioptric camera;(2) According to the imaging model, uses coplanar constraint and plane refraction constraint to recover the camera's external parameters and the refraction interface's location parameters;(3) Optimizes the camera external parameters by minimizing the error between the virtual perspective projection of 3D scene points and the virtual perspective projection of the corresponding refraction point;(4) Uses the refraction interface's location parameters and the optimized parameters to obtain the 3D coordinates of the 3D scene object in water;...