Spatial Calibration of a Dual PTZ-Fixed Camera System for Tracking Moving Objects in Video

A dual camera setup is proposed, consisting of a fixed (stationary) camera and a pan tilt zoom (PTZ) camera, employed in an automatic video surveillance system. The PTZ camera is zoomed in on a selected point in the fixed camera view and it may automatically track a moving object. For this purpose, two camera spatial calibration procedures are proposed. The PTZ camera is calibrated in relation to the fixed camera image, using interpolated look-up tables for pan and tilt values. For the calibration of the fixed camera, an extension of the Tsai algorithm is proposed, based only on measurements of distances between calibration points. This procedure reduces the time needed to obtain the calibration set and improves calibration accuracy. An algorithm for calculating PTZ values required for tracking of a moving object with the PTZ camera is also presented. The performance of the proposed algorithms is evaluated using the measured data. (C) 2013 Society for Imaging Science and Technology.