Using a board with grid pattern as the calibration object.
Dewarping catadioptric images of the calibration board to their perspective projection counterparts by using the sphere model of catadioptric camera.
Estimating the intrinsic camera parameters through nonlinear optimization according to the residual error of feature points extracted from the perspective images.
Estimating the projective lines of pixels in camera coordinate system through the corresponding pixels in image coordinate system.
