69,558 research outputs found
A system for learning statistical motion patterns
Analysis of motion patterns is an effective approach for anomaly detection and behavior prediction. Current approaches for the analysis of motion patterns depend on known scenes, where objects move in predefined ways. It is highly desirable to automatically construct object motion patterns which reflect the knowledge of the scene. In this paper, we present a system for automatically learning motion patterns for anomaly detection and behavior prediction based on a proposed algorithm for robustly tracking multiple objects. In the tracking algorithm, foreground pixels are clustered using a fast accurate fuzzy k-means algorithm. Growing and prediction of the cluster centroids of foreground pixels ensure that each cluster centroid is associated with a moving object in the scene. In the algorithm for learning motion patterns, trajectories are clustered hierarchically using spatial and temporal information and then each motion pattern is represented with a chain of Gaussian distributions. Based on the learned statistical motion patterns, statistical methods are used to detect anomalies and predict behaviors. Our system is tested using image sequences acquired, respectively, from a crowded real traffic scene and a model traffic scene. Experimental results show the robustness of the tracking algorithm, the efficiency of the algorithm for learning motion patterns, and the encouraging performance of algorithms for anomaly detection and behavior prediction
A system for learning statistical motion patterns
Analysis of motion patterns is an effective approach for anomaly detection and behavior prediction. Current approaches for the analysis of motion patterns depend on known scenes, where objects move in predefined ways. It is highly desirable to automatically construct object motion patterns which reflect the knowledge of the scene. In this paper, we present a system for automatically learning motion patterns for anomaly detection and behavior prediction based on a proposed algorithm for robustly tracking multiple objects. In the tracking algorithm, foreground pixels are clustered using a fast accurate fuzzy k-means algorithm. Growing and prediction of the cluster centroids of foreground pixels ensure that each cluster centroid is associated with a moving object in the scene. In the algorithm for learning motion patterns, trajectories are clustered hierarchically using spatial and temporal information and then each motion pattern is represented with a chain of Gaussian distributions. Based on the learned statistical motion patterns, statistical methods are used to detect anomalies and predict behaviors. Our system is tested using image sequences acquired, respectively, from a crowded real traffic scene and a model traffic scene. Experimental results show the robustness of the tracking algorithm, the efficiency of the algorithm for learning motion patterns, and the encouraging performance of algorithms for anomaly detection and behavior prediction
Human behavioural analysis with self-organizing map for ambient assisted living
This paper presents a system for automatically classifying the resting location of a moving object in an indoor environment. The system uses an unsupervised neural network (Self Organising Feature Map) fully implemented on a low-cost, low-power automated home-based surveillance system, capable of monitoring activity level of elders living alone independently. The proposed system runs on an embedded platform with a specialised ceiling-mounted video sensor for intelligent activity monitoring. The system has the ability to learn resting locations, to measure overall activity levels and to detect specific events such as potential falls. First order motion information, including first order moving average smoothing, is generated from the 2D image coordinates (trajectories). A novel edge-based object detection algorithm capable of running at a reasonable speed on the embedded platform has been developed. The classification is dynamic and achieved in real-time. The dynamic classifier is achieved using a SOFM and a probabilistic model. Experimental results show less than 20% classification error, showing the robustness of our approach over others in literature with minimal power consumption. The head location of the subject is also estimated by a novel approach capable of running on any resource limited platform with power constraints
FPGA-based Anomalous trajectory detection using SOFM
A system for automatically classifying the trajectory of a moving object in a scene as usual or suspicious is presented. The system uses an unsupervised neural network (Self Organising Feature Map) fully implemented on a reconfigurable hardware architecture (Field Programmable Gate Array) to cluster trajectories acquired over a period, in order to detect novel ones. First order motion information, including first order moving average smoothing, is generated from the 2D image coordinates (trajectories). The classification is dynamic and achieved in real-time. The dynamic classifier is achieved using a SOFM and a probabilistic model. Experimental results show less than 15\% classification error, showing the robustness of our approach over others in literature and the speed-up over the use of conventional microprocessor as compared to the use of an off-the-shelf FPGA prototyping board
A Neural System for Automated CCTV Surveillance
This paper overviews a new system, the “Owens
Tracker,” for automated identification of suspicious
pedestrian activity in a car-park.
Centralized CCTV systems relay multiple video streams
to a central point for monitoring by an operator. The
operator receives a continuous stream of information,
mostly related to normal activity, making it difficult to
maintain concentration at a sufficiently high level.
While it is difficult to place quantitative boundaries on
the number of scenes and time period over which
effective monitoring can be performed, Wallace and
Diffley [1] give some guidance, based on empirical and
anecdotal evidence, suggesting that the number of
cameras monitored by an operator be no greater than 16,
and that the period of effective monitoring may be as
low as 30 minutes before recuperation is required.
An intelligent video surveillance system should
therefore act as a filter, censuring inactive scenes and
scenes showing normal activity. By presenting the
operator only with unusual activity his/her attention is
effectively focussed, and the ratio of cameras to
operators can be increased.
The Owens Tracker learns to recognize environmentspecific
normal behaviour, and refers sequences of
unusual behaviour for operator attention. The system
was developed using standard low-resolution CCTV
cameras operating in the car-parks of Doxford Park
Industrial Estate (Sunderland, Tyne and Wear), and
targets unusual pedestrian behaviour.
The modus operandi of the system is to highlight
excursions from a learned model of normal behaviour in
the monitored scene. The system tracks objects and
extracts their centroids; behaviour is defined as the
trajectory traced by an object centroid; normality as the
trajectories typically encountered in the scene. The
essential stages in the system are: segmentation of
objects of interest; disambiguation and tracking of
multiple contacts, including the handling of occlusion
and noise, and successful tracking of objects that
“merge” during motion; identification of unusual
trajectories. These three stages are discussed in more
detail in the following sections, and the system
performance is then evaluated
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