DCT based segmentation applied to a scalable zenithal people counter

This paper faces the problem of detecting the number of customers crossing an uncontrolled access to a big store, from the information retrieved by a zenithal camera. The solution operates in real time and is scalable in two ways: allows the coverage of wide accesses (spatial scalability), and works with a level of detail enough to allow detection of carried objects (functional scalability). In order to cope with the main problems of these systems - shadows, sudden changes in global lighting, and sporadic camera motion due to vibration -, a novel DCT based segmentation is presented.