Real-time Monitoring for the Regional Crowds Status

Abstract

With the rapid development of the social economy,the massive crowd gathering appears frequently.Personnel casualties often caused by higher crowd density.So,video surveillance technology has become a national policy in many countries.Surveillance cameras have been installed in various important places of the city.Real-time monitoring of the crowds status in crowd gathering area can provide important basis for crowd management and emergency warning.Existing video-based crowd analysis can only monitor crowd status for each camera separately.We cannot get the spatial-temporal patterns of regional crowd status from a spatial perspective.In this paper,we proposed a video-GIS framework for crowd analysis.Video frames can be mapped to geographic space based on the video-GIS framework.So we can process crowd images and extract crowd density,crowd movement vector field in GIS.Then the crowd movement pattern and the main direction of crowd movement can be acquired by the vector field analysis.Finally,we design and implement a real-time monitoring system for the regional crowd status using video surveillance system and GIS.Experimental results show that:(1) previous crowd analysis methods based on the image space can only measure results by the unit of pixels.It requires further conversion if we want to get the real value.But we can get the real value directly when we process crowd images in GIS using the method we proposed.(2) The accuracy of the pixel-based low-density crowd counting estimation results can be up to 90%.The classification accuracy of the high-density crowd levels support vector machine classifier is more than 95%.So,they can fully meet the needs of crowd monitoring.(3) We can get the crowd movement pattern and the main movement direction by the analysis of crowd movement vector field in GIS.Also,we can obtain the speed of the crowd in different directions.These crowd characters all can be expressed in GIS.(4) The system we developed for the crowd monitoring can be applied to crowd management and emergency warning.It can provide decision making basis for emergencies prevention and crowd divert.