Virtual reality has been a subject of great interest. Less attention has been paid to the related field of Augmented Reality, despite its similar potential. The difference between Virtual Reality and Augmented Reality is in their treatment of the real world. Virtual Reality immerse a user inside a virtual world that completely
replaces the real world outside. In contrast, Augmented Reality let the user see the real world around him and augment the user’s view of the real world by overlaying or composing three-dimensional virtual objects with their real world counterparts. Ideally, it would seem to the user that the virtual and real objects coexisted.

The key issue to realize Augmented Reality is the registration problem, the registration of the object virtual information is overlaid. In typical augmented reality systems developed, head-trackers are used for tracking user’s head position/orientation, rangefiner or sonar sensor is used for detecting or tracking the object pose in the world. The problems are lack of accuracy and latency of the system. Most commercially available head-trackers do not provide sufficient accuracy and range. The rangefiner and sonar sensor is not sufficient enough for its speed and accuracy.

We are trying to apply computer vision to the registration problem in Augmented Reality. From computer vision point of view, it will be a real-time visual tracking system of the known 3D object using intensity images.