Vehicle entry or exit detection in each parking slot from outdoor surveillance camera images

Abstract

This paper proposes a method of detecting entry and exit of vehicles in each parking slot using a surveillance camera placed outdoors. To specify the respective parking slot areas in a surveillance camera image, polygonal windows are set by projecting rectangular boxes, each of which surrounds the typical body of a vehicle parked in each slot, onto the image based on the perspective projection matrix associated with the surveillance camera. The projection matrix is semi-automatically calculated by providing 3D coordinates to a small number of points picked up from the surveillance camera image. Then, a joint intensity histogram between a pair of images taken by the same camera with a certain time interval is calculated in each window. By analyzing the distribution of the histogram, entry and exit of vehicles in the slot can be robustly detected without being affected by lighting change during the time interval.