Pyramid Coding for Functional Scene Element Recognition in Video Scenes

Recognizing functional scene elemeeents in video scenes based on the behaviors of moving o bjects that interact with them is an emerging problem of interest. Existing approaches have a limited ability to chhharacterize elements such as cross-walks, intersections, anddd buildings that have low activity, are multi-modal, or haveee indirect evidence. Our approach recognizes the low activvvity and multi-model elements (crosswalks/intersections) by introducing a hierarchy of descriptive clusters to ffform a pyramid of codebooks that is sparse in the numbbber of clusters and dense in content. The incorporation ooof local behavioral context such as person-enter-building aaand vehicle-parking nearby enables the detection of elemennnts that do not have direct motion-based evidence, e.g. buuuildings. These two contributions significantly improveee scene element recognition when compared against thhhree state-of-the-art approaches. Results are shown on tyyypical ground level surveillance video and for the first time on the more complex Wide Area Motion Imagery.