Intrusion detection system using contour-based multi-planar visual hull method

In this paper we propose a practical intrusion detection system based on a contour-based multi-planar visual hull method. The system consists of several sets of a camera and a PC connected via network. Prior to the monitoring, a system manager would set up several sensitive planes in the world using a GUI. To detect the intruding objects, images taken by the cameras are compared with a maintained background image using PISC method. Then the contour of the object region on an image is traced and transformed to the coordinate of sensitive plane. The contours are collected to a single PC and existence of a common region is judged. If the intruding object exceeds the sensitive plane, the contours from each PC would have some common regions. If the intruder occludes the critical point on the sensitive planes from the all cameras to avoid observation, the system also alerts to the user. This system does not reconstruct the shape of the object, but the system is able to handle 3-D protection volumes because multiple sensitive planes can be set arbitrary. This system does not require us to calibrate the camera because this system is based on 2-D homography.