A Linear Camera Self-calibration Approach from Four Points

In this paper a new approach for obtaining the intrinsic camera parameters based on circular points is proposed. This method just requires the camera to observe a planar pattern with square at a few different unknown orientations (at least three). With the image of four corner points of square we can obtain the image of circular points (ICPs) linearly. Without conic fitting, pattern matching and metric information of square, camera intrinsic parameters can be obtained automatically. This method is particularly useful for those people who want to get camera intrinsic parameters fast with relative high precision. Simulation and real planar pattern experiment show that the new approach is convenient, accurate and robust.