tbeta is a new tool developed by the NUI Group Community. tbeta acts as an image processing layer to take in image data and output tracking data for multitouch applications. Whether FTIR or DI, scratch built multitouch systems generate IR video streams that need to be processed to find fingertips. tbeta can take this or any arbitrary video stream and run it through a series of filters to generate the touch data. This data is sent as OSC TUIO, a standard protocol for touch events. Along with the camera and input switcher, tbeta also aids in system calibration. I works on Windows, OSX, and Linux. Have a look at the getting started guide for a better idea of how it works.
[Christopher Jette] did a amazing job converting a 56″ rear projection television into a multitouch display. His original inspiration came from this drafting table project. The screen is a large sheet of 1/2″ acrylic with a screen material attached to the back side. The screen edge is surrounded by 168 IR LEDs. When a finger tip touches the surface it scatters the LEDs’ IR light. A webcam sees this scattered light and determines where the fingers are. Inside the box is a standard video projector. This is a great reuse of old equipment and we love to see a hobbyist making up ground where manufacturers aren’t. For more info on multitouch projects, we suggest the Natural User Interface Group. Here’s a video of [Christopher]’s display in action: