These patents are generally related to imaging systems. First set of patents disclose techniques to provide human behaviour recognition systems by studying human body gestures. Second set of patents disclose techniques to provide human gesture recognition systems to control self-service machines. Third set of patents disclose techniques to provide real-time computer vision systems to track moving objects in a scene where the systems use novel algorithms to locate the objects without using any search procedures. Further, techniques are disclosed to provide low-cost non-imaging eye tracker system for computer control, optical body tracker, tracking and gesture recognition system particularly suited to vehicular control applications. This technology can be implemented in home automation, home security appliances, map control (weather, military etc), sports, games, etc.