Camera calibration using multiple images

This paper describes a method for camera calibration. The system consists of a static camera which takes a sequence of images of a calibration plane rotating around a fixed axis. There is no requirement for any exact positioning of the camera or calibration plane.From each image of the sequence, the vanishing points and hence the vanishing line of the calibration plane are determined. As the calibration plane rotates, each vanishing point moves along a locus which is a conic section, and the vanishing line generates an envelope which is also a conic section. We describe how such conics can be used to determine the camera's focal length, the principal point (the intersection of the optic axis with the image plane), and the aspect ratio.