Observing the Entropy of Crowd Movements

Abstract

Providing security and managing it as well as trying to understand how it behaves have become an important research topic in our day. The aim of this study is to calculate the entropy value of the crowd movement regionally and to track how it. changes in time. Because, excessive changes in the entropy value in time might point to abnormal behaviour in the region. The motion information obtained from the optical flow method from the image in parallel to the target was converted to motion orbits by particle advection. Motion orbits are mapped into by the Braid Theory and entropy value is calculated. Braid Theory is a mathematical method that is used to express entropy as a qualitative value by determining the interaction among the movement orbits. The results are tested according to the video sequence in the PETS2009 and UCF database and they show that this method is functional for observing how the entropy changes in time within the crowd movement.