Recent survey on crowd density estimation and counting for visual surveillance

Automated crowd density estimation and counting are popular and important topic in crowd analysis. The last decades witnessed different of many significant publications in this field and it has been and still a challenging problem for automatic visual surveillance over many years. This paper presents a survey on crowd density estimation and counting methods employed for visual surveillance in the perspective of computer vision research. This survey covers two main approaches which are direct approach (i.e., object based target detection) and indirect approach (e.g. pixel-based, texture-based, and corner points based analysis). This review categorizes and delineates several crowd density estimation and counting methods that have been applied for the examination of crowd scenes.