The SQUASH 1000 tangible user interface system

A hand-held object whose pose can be determined automatically is useful for augmented reality (AR) and other applications needing human-computer interaction. Some existing such input devices use active (ex. LED lighting) or passive markers to be recognized in a video image by computer vision. Markers are typically mounted onto flat objects which are not ergonomic, or can only have limited number of sides due to the small library and inter-marker confusion rate of the marker system used. A system is presented based on the ARTag fiducial marker system where objects of arbitrary shape can be covered with many small markers, the pose of the object is recovered automatically and can be used as an input device. Other tangible user interface systems require specialized hardware, whereas this approach needs only a printer, a video camera or Webcam, and a large garden vegetable. The utility of this system both for measuring pose and for 3D modeling is shown.