Multi-view Event Detection in Crowded Scenes Using Tracklet Plots

Track let plots (TPs) describe the motion patterns of a small crowd or a large group of people in a given short time span. This feature can be useful in the context of a Bag-of-Words modelling for the recognition of events or actions that unfold in the scene. This work describes a method where evidence from multiple viewpoints is combined. By obtaining this feature for each of the views, and synchronising the available video streams, a feature-level fusion method by concatenation can be effortlessly applied. The presented system is able to recognise specific events in large groups of people from multiple cameras, and to perform equally well as compared to the best single view available. Furthermore, the dimension of the concatenated feature can be reduced by one order of magnitude without loss of performance.