Camera Calibration Using Circle and Right Angles

In this paper, a new method is proposed for camera calibration using planar pattern which includes a circle and right angles. It is shown that a dual conic constraint on the vanishing line of a plane can be derived from a right angle and a circle on the same plane. Given an image of a model plane containing a circle and three right angles, the vanishing line and the images of the circular points can be uniquely determined. As a result, camera calibration can be achieved by taking several images of the model plane from different view angles. There are three advantages of the proposed method. First, no correspondences between images need to be established. Secondly, conies and lines forming the right angles in an image can be extracted and fitted very accurately. Thirdly, it is practical as circular patterns and right angles are widely available. Experiments with real images demonstrate the performance of the presented method