Interactive calibration of a PTZ camera for surveillance applications

摘要

In this paper, we describe a novel method for easy and precise external and internal calibration of pan-tilt- zoom cameras for surveillance applications. The external calibration module assumes known height of the camera and allows an installer to determine camera position and orientation by pointing the camera at several points in the area and clicking on their respective position on the area map shown in the GUI. The only requirements for internal camera calibration are that the maximum zoom-out of the camera is known (this is typically provided by the manufacturer) and that the installer has pointed the camera to a texture-rich area. We compute not only focal length, pixel aspect ratio and principal point but also, the relationship between camera zoom settings and the focal length. Our calibration method provides accurate and consistent results and is currently under commercial implementation.