Crowd monitoring: state-of-the-art and future directions

With the growing concerns over public safety, the importance of crowd monitoring is being realized by varioussecurity and event management agencies worldwide. Estimation of crowd dynamics can help such agencies in prevention ofany unanticipated accidents or issues. Research on crowd monitoring has been underway since the past few decades. Conventionalcrowd monitoring systems mainly rely on computer vision approach. Due to predominant use of videos/ imagesequences, the existing techniques may raise data privacy concerns. This has led to development of new crowd monitoringtechniques which are privacy preserving and require minimum public participation. This paper aims to serve as a single andsufficient source of information to the concerned researchers on various aspects of crowd monitoring and also provide futuredirections which can be helpful in developing advanced crowd monitoring techniques.