All the camera calibration tools I have found so far are based on chessboards. But I have some data where I know the 3D and 2D locations of a load of non-chessboard points in images (X and Y matrices) and I would like to calibrate for radial distortion and camera matrix directly from them. Do we have a way to do this in CV? Like, perhaps the chessboard functions are calling something internally with X and Y matrices - after doing the chessboard detection -- which I could call directly ?