Electronics company NEC have recently announced that they developed a system that combines RFID and surveillance camera:
According to RFID in Japan blog: "the system can continuously track people or vehicles. The system uses a camera and RFID in a complementary fashion. When a camera recognizes a moving entity, the system reads information from an RFID tag (carried by a person or a vehicle). Also, it uses RFID to track rough positions of moving entities when they cannot be detected by a camera. The system automatically switches between camera-based and RFID-based tracking."