Calibrating pan-tilt cameras in wide-area surveillance networks
Pan-tilt cameras are often used as components of wide-area surveillance systems. It is necessary to cali-brate these cameras in relation to one another in order to obtain a consistent representation of the entire space. Existing methods for calibrating pan-tilt cameras have assumed an idealized model of camera mechanics. In ad-dition, most methods have been calibrated using only a small range of camera motion. This paper presents a method for calibrating pan-tilt cameras that introduces a more complete model of cam-era motion. Pan and tilt rotations are modeled as occur-ring around arbitrary axes in space. In addition, the wide area surveillance system itself is used to build a large virtual calibration object, resulting in better calibration than would be possible with a single small calibration target. Finally, the proposed enhancements are validated experimentally, with comparisons showing the improve-ment provided over more traditional methods.
ICCV 2003 Paper - PanTiltCalib_ICCV2003.pdf