Laboratory of Informatics of Grenoble Engineering Human-Computer Interaction Research Group

Engineering Human-Computer Interaction
Research Group

Single User MultiTouch on the DiamondTouch: From 2×1D to 2D

In Proceedings of the ACM International Conference on Interactive Tabletops and Surfaces. In Actes de la Conférence Internationale Interactive Tabletops and Surfaces (TableTop'2009) . pages 1--8. 2009.

François Bérard, Yann Laurillau


The DiamondTouch is a widely used multi-touch surface that offers high quality touch detection and user identification. But its underlying detection mechanism relies on two 1D projections (x and y) of the 2D surface. This creates ambiguous responses when a single user exercises multiple contacts on the surface and limits the ability of the DiamondTouch to provide full support of common multi-touch interactions such as the unconstrained translation, rotation and scaling of objects with two fingers. This paper presents our solution to reduce this limitation. Our approach is based on a precise modeling, using mixtures of Gaussians, of the touch responses on each array of antennas. This greatly reduces the shadowing of the touch locations when two or more fingers align with each other. We use these accurate touch detections to implement two 1D touch trackers and a global 2D tracker. The evaluation of our system shows that, in many situations, it can provide the complete 2D locations of at least two contacts points from the same user.