Robust Auto-Calibration of a PTZ Camera with Non-overlapping FOV

We consider the problem of auto-calibration of cameras, which are fixed in location but are free to rotate while changing their internal parameters by zooming. Our method is based on line correspondences between two views, which may have non-overlapping field of view. Camera calibration from images having non-overlapping field of view is the basic motivation behind this research. The key observation is that the planes formed by the optic center and the line correspondences are really the same plane. We use this fact together with the orthonormality constraint of the rotation matrix to estimate the unknown camera parameters. We show experimental results on synthetic and real data, and analyze the accuracy and stability of our method.