%0 Journal Article %J IEEE/RSJ IROS Workshop: From sensors to human spatial concepts (FS2HSC) %D 2007 %T Human activity understanding using visibility context %A Morariu,V.I. %A Prasad,V. S.N %A Davis, Larry S. %X Visibility in architectural layouts affects humannavigation, so a suitable representation of visibility context is useful in understanding human activity. Motivated by studies of spatial behavior, we use a set of features from visibility analysis to represent spatial context in the interpretation of human activity. An agent’s goal, belief about the world, trajectory and visible layout are considered to be random variables that evolve with time during the agent’s movement, and are modeled in a Bayesian framework. We design a search-based task in a sprite-world, and compare the results of our framework to those of human subject experiments. Our findings confirm that knowledge of spatial layout improves human interpretations of the trajectories (implying that visibility context is useful in this task). Since our framework demonstrates performance close to that of human subjects with knowledge of spatial layout, our findings confirm that our model makes adequate use of visibility context. In addition, the representation we use for visibility context allows our model to generalize well when presented with new scenes. %B IEEE/RSJ IROS Workshop: From sensors to human spatial concepts (FS2HSC) %8 2007/// %G eng