A new method of detecting fingertip touch for the projector-camera HCI system

This paper proposes a new fingertip touch detecting method with high accuracy for the human-computer interaction based on one projector and a single camera. A finger model composed of a quarter-sphere and half a cylinder is introduced, and the relationship between the finger contour and its shadow based on this model is given out. The way to estimate the distance between finger and the projected surface is presented and discussed. Experimental results show that our approach can achieve a precision of about 2mm when the distance from the projected surface to the projector is 50cm and the button size will not influence the precision.