About the Self-calibration of a Rotating and Zooming Camera: Theory and Practice

This paper deals with first the uniqueness of the selfcalibration of a rotating and zooming camera theoretically. We assume that the principal point and the aspect ratio are fixed but the focal length changes as the camera moves. In this case, at least one inter-image homography is required in order to compute the internal calibration parameters as well as the rotation. Secondly, we analyze the effects of the deviation of the principal point on the estimation of the focal length and the rotation. The more the camera changes its zoom, the larger the effects are, and the larger the rotation angle is, the smaller the effects are. Thus, we may take the image center as the principal point in practical applications. Experiments using real images are given