20 February 2013 Group localisation and unsupervised detection and classification of basic crowd behaviour events for surveillance applications
Author Affiliations +
Abstract
Technology for monitoring crowd behaviour is in demand for surveillance and security applications. The trend in research is to tackle detection of complex crowd behaviour events (panic, ght, evacuation etc.) directly using machine learning techniques. In this paper, we present a contrary, bottom-up approach seeking basic group information: (1) instantaneous location and (2) the merge, split and lateral slide-by events - the three basic motion patterns comprising any crowd behaviour. The focus on such generic group information makes our algorithm suitable as a building block in a variety of surveillance systems, possibly integrated with static content analysis solutions. Our feature extraction framework has optical ow in its core. The framework is universal being motion-based, rather than object-detection-based and generates a large variety of motion-blob- characterising features useful for an array of classi cation problems. Motion-based characterisation is performed on a group as an atomic whole and not by means of superposition of individual human motions. Within that feature space, our classi cation system makes decisions based on heuristic rules and thresholds, without machine learning. Our system performs well on group localisation, consistently generating contours around both moving and halted groups. The visual output of our periodical group localisation is equivalent to tracking and the group contour accuracy ranges from adequate to exceptionally good. The system successfully detects and classi es within our merge/split/slide-by event space in surveillance-type video sequences, di ering in resolution, scale, quality and motion content. Quantitatively, its performance is characterised by a good recall: 83% on detection and 71% on combined detection and classi cation.
© (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Nadejda S. Roubtsova, Nadejda S. Roubtsova, Peter H. N. de With, Peter H. N. de With, } "Group localisation and unsupervised detection and classification of basic crowd behaviour events for surveillance applications", Proc. SPIE 8663, Video Surveillance and Transportation Imaging Applications, 866302 (20 February 2013); doi: 10.1117/12.2001427; https://doi.org/10.1117/12.2001427
PROCEEDINGS
20 PAGES


SHARE
Back to Top