Title
Bridging the past, present and future: Modeling scene activities from event relationships and global rules
Abstract
This paper addresses the discovery of activities and learns the underlying processes that govern their occurrences over time in complex surveillance scenes. To this end, we propose a novel topic model that accounts for the two main factors that affect these occurrences: (1) the existence of global scene states that regulate which of the activities can spontaneously occur; (2) local rules that link past activity occurrences to current ones with temporal lags. These complementary factors are mixed in the probabilistic generative process, thanks to the use of a binary random variable that selects for each activity occurrence which one of the above two factors is applicable. All model parameters are efficiently inferred using a collapsed Gibbs sampling inference scheme. Experiments on various datasets from the literature show that the model is able to capture temporal processes at multiple scales: the scene-level first order Markovian process, and causal relationships amongst activities that can be used to predict which activity can happen after another one, and after what delay, thus providing a rich interpretation of the scene's dynamical content.
Year
Venue
Keywords
2012
CVPR
past activity occurrence,scene activity,activity occurrence,global scene state,temporal process,global rule,novel topic model,model parameter,temporal lag,complex surveillance scene,order Markovian process,event relationship,probabilistic generative process
DocType
Citations 
PageRank 
Conference
1
0.36
References 
Authors
0
1
Name
Order
Citations
PageRank
Remi Emonet11038.49