Fully automatic camera calibration method based on circular markers

Camera calibration is a critical process to acquire 3D metric information from 2D images, and is a time consuming step because the first step of finding correspondences is often performed manually. In this paper a new calibration method is presented, which allows a camera to be calibrated fully automatically. In this method, five big circles are added to the common circle pattern and calibration is carried out by aiming to the modified planar circle pattern and simply taking images. This system can robustly find correspondences and provide the input to the Zhang's coplanar calibration algorithm. Experiments show that this system is robust for pattern images under uneven illumination or in different scenes.