Leveraging Graphics Hardware for Vision Based Human Computer Interaction

We present a system which allows users to draw on arbitrary display surfaces. The system is implemented using consumer electronics; data is gathered with a webcam, and most video analysis is done on a desktop graphics card. Two variants of the core system are discussed. In the first, users draw on a computer monitor using a laser pointer. In the second, a light pen is used to draw on a display surface created by back-projecting onto a plexiglass plate. The laser pointer system presents a more challenging data filtering problem. These challenges may be addressed through additional processing, though the results from the back-projection system remain superior.