Master-slave tracking algorithm using dual PTZ cameras based on ground plane constraint

Master-slave camera system had been widely used in visual surveillance domain because both large-view information and high-resolution local-view information of the tracked object could be obtained at the same time. For the widely demanding of intelligent visual surveillance, a master-salve tracking algorithm using dual PTZ(pan-tilt-zoom) cameras based on ground plane constraint was presented. The proposed method could be divided into two stages: offline calibration and online tracking. In offline stage, the view-to-view homography induced by the ground plane was computed using object matching from two cameras. A novel method that automatically estimated homography from synchronized video streams of the two cameras was presented. Compared with traditional methods, the proposed method didn't need calibration tools, and without the need of manual intervention. Then principal point and equivalent focal length were estimated using matched features. In online stage, the calculated homography transformation was used to establish coordinate correspondence of the master and slave cameras. With the estimated principal point and equivalent focal length, the control parameters of the salve camera could be computed. Therefore, master-salve tracking could be realized. Compared with other methods, the proposed algorithm can be used in the case of wide baseline. The proposed method can also adapt to the depth change of tracked target. Meanwhile, the requirements for real time master-salve tracking can be meeted. Quantitative results in the indoor and outdoor scene show good performance of the proposed approach.