Fast technique for moving shadow detection in image sequences

Automatic video surveillance systems typically involve tasks of moving object detection, object tracking, event analysis and detection of abnormality. One of the key requirements of scene understanding is detection and removal of moving shadows. In the context of real time automatic surveillance systems, considering the various tasks to be performed, detection of moving shadows needs to be performed with minimal computational complexity. Many algorithms have been proposed in the literature that deals with moving shadow detection. The existing algorithms treat tracking of objects and shadow detection tasks in an isolated manner. In this paper we present a technique for shadow detection, which uses motion information from the tracking module and hence greatly reduces the computational complexity.