Extraction of semantic description of events using Bayesian networks

In this paper, we use Bayesian belief networks to sta- tistically model the trends for event detection. We automatically detect non-rigid object trajectories for object motion units. Then, we use dominant and secondary trajectories of a single object in several consecutive motion unite, to understand semantic actions or those of more than one object to recognize semantic interactions between objects. We demonstrate sample Bayesian networks to detect events and extract the event descriptions, such as "catch the ball", "throw the ball" and "walk".