Detecting A Suspicious Behavior Using A Spatiotemporal Model

A spatiotemporal model based method was proposed for detecting a suspicious behavior using an advanced background subtraction technique. The method was based on the fact that a person walking straightly with constant speed formed cylindrical cavity just like a wormhole in a three-dimensional spatiotemporal space. These wormholes were divided into those having dominant inclinations and those having different ones. The suspicious persons were detected as the latter. An advanced background subtraction method was introduced to extract moving persons from sequential images captured by a fixed camera, and the resultant binary images were used for forming the spatiotemporal model. A projection method was applied to the model, and the major inclination of them was obtained as the minimum obstruction view-angle. The dominant wormholes were filled by a selective successive region growing algorithm, and the moving trajectory of a suspicious person was detected as one of the remaining wormholes. The trajectory gave us a mask for separating the person from the others.The proposed method was characterized by its high performance in detectability and in separability of the person with rare behavior. Actually, the method detected a standing person as a suspicious one. The proposed method was successfully applied to a video captured on an event