Self-Calibrating Camera-Projection Systems: A Natural Interface for Presentation Control

Traditional approaches to computer-based presentation require the user to directly control the pre-sentation software using either a keyboard or mouse, distracting the user from the audience. Thispaper presents a self-calibrating camera-projector system that enables the user to control presenta-tions using a standard laser pointer (or other pointing device). A camera-projector system consistsof a computer connected to an LCD projector and a consumer-level digital camera aimed at thepresentation screen. Although the locations, orientations and optical parameters of the camera andprojector are unknown, the projector-camera calibrates itself by inferring the mapping betweenpixels in the camera image to pixels in the presentation slide. The camera is subsequently used todetect the position of the pointing device (such as a laser pointer dot) on the screen — allowing thelaser pointer to emulate the pointing actions of a mouse. The user may then select active regionsin the presentation, or even draw on the projected image. The camera-projector system is portableand inexpensive, requiring only a low-resolution, consumer-level digital camera and easily runs ona standard laptop computer. It has been integrated into a complete camera-assisted presentationsystem and deployed as a presentation tool since December 1999, and has received very favorablefeedback.