In winter 2007/08 a multi touch table has been built in our group. We designed and constructed the table in a student project. The table is based on the FTIR technology. We enhanced the robustness of our table against ambient light by alternating the LEDs in sync with the camera.

Touch Sensing based on FTIR in the Presence of Ambient Light
Marc Alexa, Björn Bollensdorff, Ingo Bressler, Stefan Elstner, Uwe Hahne, Nino Kettlitz, Norbert Lindow, Robert Lubkoll, Ronald Richter, Claudia Stripf, Sebastian Szczepanski, Karl Wessel, Carsten Zander
Poster at Siggraph '08
Abstract for Siggraph '08 Poster
Video

A FTIR based multi touch table using pulsed illumination for noise suppression
Uwe Hahne, Marc Alexa, Björn Bollensdorff, Ingo Bressler, Stefan Elstner,
Robert Lubkoll and Claudia Stripf
Slides from talk at Multi-Touch workshop in Hagenberg, Austria
Abstract for the talk

Multi-touch Focus+Context Sketch-based Interaction
Uwe Hahne, Jonas Schild, Stefan Elstner and Marc Alexa
SBIM '09: Proceedings of the 6th Eurographics Symposium on Sketch-Based Interfaces and Modeling, ACM, 2009, 77-83
Slides Publication