Deictic Gestures with a Time-of-Flight Camera

We present a robust detector for deictic gestures based on a time-of-flight (TOF) camera, a combined range and intensity image sensor. Pointing direction is used to determine whether the gesture is intended for the system at all and to assign different meanings to the same gesture depending on pointing direction. We use the gestures to control a slideshow presentation: Making a "thumbs-up" gesture while pointing to the left or right of the screen switches to the previous or next slide. Pointing at the screen causes a "virtual laser pointer" to appear. Since the pointing direction is estimated in 3D, the user can move freely within the field of view of the camera after the system was calibrated. The pointing direction is measured with an absolute accuracy of 0.6 degrees and a measurement noise of 0.9 degrees near the center of the screen.