A Logic Programming Approach to Activity Recognition

The output of the former type of recognition is a set of activities taking place in a short period of time: 'short-term activities'. The output of the latter type of recognition is a set of'long-term activities', ie predefined temporal combinations of short-term activities. We focus on high-level recognition. We define a set of long-term activities of interest, such as'fighting' and'meeting', as temporal combinations of short-term activities -- eg, 'walking', 'running', and'inactive' (standing still) -- using a logic programming implementation of the Event Calculus [9]. More precisely, we employ the Event Calculus to express the temporal constraints on a set of short-term activities that, if satisfied, lead to the recognition of a long-term activity. We presented preliminary results on activity recognition from video content in [2].