Hybrid sensors calibration: Application to pattern recognition and tracking

Video surveillance becomes more and more extended in industry and often involves automatic calibration system to remain efficient. In this paper, a video-surveillance system that uses stationary-dynamic cameras devices is presented. The static camera is used to monitor the largest scene but with a small resolution : master-slave system. When it detects a moving object, the Pan-Tilt-Zoom (PTZ) camera is controlled to be centered on this object with a high resolution. We use a method of camera-to-camera calibration, integrating zoom calibration in order to command the angles and the zoom of the PTZ camera. This method enables to take into account the intrinsic camera parameters, the 3D scene geometry and the fact that the mechanism of inexpensive camera does not fit the classical geometrical model. Finally, the results of precision and accuracy of this algorithm are highlighted on real cases to qualify subjectively the value of theses errors for more complex surveillance applications like pattern recognition or tracking.