Pedestrians Gathering Detection Based on Normalized Foreground and Two-dimension Joint Entropy

A normalized foreground computing approach based on the camera perspective effect is presented.A two-dimensional probability density for the binary foreground is calculated through classic joint probability distribution theory,and then the two-dimension joint entropy is calculated.Finally,a novel model based on normalized foreground and two-dimension joint entropy for detecting pedestrian gathering is proposed.Experimental results show that this model can quickly and effectively detect a pedestrian gathering event in a surveillance scene.