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People trajectory analysis and anomaly detection
People trajectory analysis is a recurrent task in many pattern recognition applications, such as surveillance, behavior analysis, video annotation, and many others. We develop a new framework for analyzing trajectory shape, invariant to spatial shifts of the people motion in the scene.
![Von mises model for trajectory analysis Von mises model for trajectory analysis](https://aimagelab.ing.unimore.it/imagelab/uploadedImages/000099.png)
In order to cope with the noise and the uncertainty of the trajectory samples, we propose to describe the trajectories as a sequence of angles modeled by distributions of circular statistics, i.e., a mixture of von Mises (MovM) distributions. To deal with MovM, we define a new specific expectation-maximization (EM) algorithm for estimating the parameters and derive a closed form of the Bhattacharyya distance between single von Mises pdfs. Trajectories are then modeled with a sequence of symbols, corresponding to the most suitable distribution in the mixture, and compared each other after a global alignment procedure to cope with trajectories of different lengths.
The trajectories in the training set are clustered according to their shape similarity in an off-line phase, and testing trajectories are then classified with a specific on-line EM, based on sufficient statistics. The approach is particularly suitable for classifying people trajectories in video surveillance, searching for abnormal (i.e., infrequent) paths.
Publications
1 | Calderara, Simone; Cucchiara, Rita "Understanding dyadic interactions applying proxemic theory on videosurveillance trajectories" 2012 IEEE Computer Society Conference on Computer Vision and Pattern Recognition Workshops, Providence, RI, usa, pp. 20 -27 , 16-21 June 2012, 2012 | DOI: 10.1109/CVPRW.2012.6239351 Conference |
2 | Calderara, Simone; Prati, Andrea; Cucchiara, Rita "Integrate tool for online analysis and offline mining of people trajectories" IET COMPUTER VISION, vol. 6, pp. 334 -347 , 2012 | DOI: 10.1049/iet-cvi.2010.0143 Journal |
3 |
Calderara, Simone; Prati, Andrea; Cucchiara, Rita
"Mixtures of von Mises Distributions for People Trajectory Shape Analysis"
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY,
vol. 21,
pp. 457
-471
,
2011
| DOI: 10.1109/TCSVT.2011.2125550
Journal
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4 | Calderara, Simone; Uri, Heinemann; Prati, Andrea; Cucchiara, Rita; Naftali, Tishby "Detecting Anomalies in People’s Trajectories using Spectral Graph Analysis" COMPUTER VISION AND IMAGE UNDERSTANDING, vol. 115, pp. 1099 -1111 , 2011 | DOI: 10.1016/j.cviu.2011.03.003 Journal |
5 |
Calderara, Simone; Prati, Andrea; Cucchiara, Rita
"Alignment-based Similarity of People Trajectories using Semi-directional Statistics"
2010 20th international conference on Pattern Recognition: ICPR 2010,
Istanbul, tur,
pp. 4275
-4278
,
23-26 August 2010,
2010
| DOI: 10.1109/ICPR.2010.1039
Conference
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6 | Calderara, Simone; Cucchiara, Rita "People trajectory mining with statistical pattern recognition" Computer Vision and Pattern Recognition Workshops (CVPRW), 2010 IEEE Computer Society Conference on, San Francisco, USA, pp. 1 -8 , June 13 2010, 2010 | DOI: 10.1109/CVPRW.2010.5543158 Conference |
7 |
Calderara, Simone; C., Alaimo; Prati, Andrea; Cucchiara, Rita
"A Real-Time System for Abnormal Path Detection"
Proceedings of 3rd International Conference on Imaging for Crime Detection and Prevention (ICDP-09),
vol. 2009,
London, gbr,
pp. 1
-6
,
3 December 2009,
2009
| DOI: 10.1049/ic.2009.0251
Conference
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8 |
Calderara, Simone; Prati, Andrea; Cucchiara, Rita
"Video surveillance and multimedia forensics: an application to trajectory analysis"
Proceedings of the First ACM Workshop on Multimedia in Forensics,
Beijing, China,
pp. 13
-18
,
19-24 October 2009,
2009
| DOI: 10.1145/1631081.1631085
Conference
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9 |
Calderara, Simone; Cucchiara, Rita; Prati, Andrea; Vezzani, Roberto
"Statistical Pattern Recognition for Multi-Camera Detection, Tracking and Trajectory Analysis"
Multi-Camera Networks: Concepts and Applications,
Electrical Engineering,
pp. 389
-413
,
2009
| DOI: 10.1016/B978-0-12-374633-7.00018-5
Chapter in Book
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