Calibration of a Pan/Tilt/Zoom Camera by a Simple Camera Model

Abstract

We propose simple model for calibrating of our pan/tilt/zoom camera, which consists of two rotation stages, an electrically-controlled zoom lens, and a CCD camera. The simple model assumes that zoom changes do not cause any change in the optical axis, the image center, the position of the image plane of camera in world coordinates system, or the rotation axes of pan/tilt. We show that when our model is used, calibration can be achieved independently of the zoom setting and the number of parameters that must be estimated in calibration decreases.
Because calibration of the pan/tilt/zoom camera was achieved, we can obtain the images by which the viewing angle and the magnification are set in an arbitrary value. And we show that the images are easily integrated using the position between the images derived from the estimated parameters.