Sensing the depth (distance from the surface) of fingers/hands near a tabletop is very important. It allows us to use three-dimensional (3D) gesture interaction in multi-touch applications as we do in the real world. We introduce Z-touch, a multi-touch table that can sense the approximate postures of fingers or hands in the proximity of the tabletop's surface. Z-touch uses a vision-based posture sensing system. Multilayered infrared (IR) laser planes are synchronized with shutter signals from a high-speed camera, which captures each layer of the laser images. A depth map is obtained by using the captured image. Our prototype works at ~30 fps. Z-touch not only uses with the finger/hand contact points but also the angle of the hovering fingers. The interaction with the finger angles is unique and allows users to control multiple parameters by using a single finger. In this study, we introduce the principle of the method of finger detection and its applications (e.g., drawing, map zooming viewer, Bezier curve control).
['Yoshiki Takeoka', 'Takashi Miyaki', 'Jun Rekimoto']
Z-touch: an infrastructure for 3d gesture interaction in the proximity of tabletop surfaces