A rear-projection multi-touch tabletop display was augmented with hand tracking utilizing computer vision techniques. While both touch detection and hand tracking can be independently useful for achieving interaction with tabletop displays, these techniques are not reliable when multiple users in close proximity simultaneously interact with the display. To solve this problem, we combine touch detection and hand tracking techniques in order to allow multiple users to simultaneously interact with the display without interference. Our hope is that by considering activities occurring on and above a tabletop display, multiuser interaction will become more natural and useful, which should ultimately support collaborative work.
