Motion tracking with reflections - 3D pointing device with self-calibrating mirror system

We propose a system that uses a camera and a mirror to input behaviour of a pointer in 3D space. Using direct and reflection images of the pointer obtained from single directional camera input, the system computes the 3D positions and the normal vector of the mirror simultaneously. Although the system can only input the "relative positions" of the pointer, in terms of 3D locations without scale factor, calibration of the mirror orientation is not needed. Thus, the system presents a very simple and inexpensive way of implementing an interaction device.