Automatic Lens Distortion Estimation for an Active Camera

This paper proposes a new algorithm for estimating lens distortion for a pan- tilt-zoom camera. No calibration pattern is needed: detection of a single feature point at different camera configurations allows the generation of a virtual cali- bration pattern which is composed of points that, in an undistorted image, are ensured to lie on straight lines. An iterative algorithm estimates lens distortion by minimizing a non-straightness error metric solving two linear subproblems. Experiments on synthetic and real images show the validity of the proposed method.