RENCI Vis Group Multi-Touch Blog

Developing multitouch hardware and applications for research and experimentation.

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Weekly Issue: Duke Multi-Touch Wall

Duke Multi-Touch Wall Development - System

November 11, 2008 (19:01) | Duke Multi-Touch Wall | 2 comments

The Duke Multi-Touch Wall uses 8 cameras to detect touches across the large 13.5-foot wide x 5-foot tall screen. These cameras are connected via network cables to a Camera Control Node where a separate instance of Touchlib is running for each camera. The Camera Control Node handles the image processing and blob tracking for [...]

Multi-Touch Calibration Device

November 10, 2008 (13:35) | Duke Multi-Touch Wall, Multi-Touch | No comments

Aligning the detected touches with the projected screen requires the use of a calibration application built into Touchlib. Creating precise touches is made easier using the calibration tool we developed. Since there can be variations in the illumination behind (or under) the projection screen, it’s easier to turn off the illuminators and use an infra [...]

Duke Multi-Touch Wall Development - Hardware Part 3

November 7, 2008 (17:11) | Duke Multi-Touch Wall | No comments

Installation
Construction included the building of the 80/20 frame, mounting the projectors, cameras and illuminators. Then came the screen installation…
The screen is a single piece of 3/8″ acrylic mounted into an extruded aluminum frame. This assembly is clamped onto the 80/20 frame and supported by aluminum plates.
A look back stage: Cameras, illuminators and projectors… We also [...]

Duke Multi-Touch Wall Development - Hardware Part 2

September 22, 2008 (16:24) | Duke Multi-Touch Wall | No comments

Cameras
The touch detection for our direct illumination (DI) wall is based on the GC660 GigE camera from Prosilica. At VGA resolution (659 x 493), each GC660 can capture images up to 120 fps. Eight (8) of these cameras are connected via a network switch to capture the entire 13.5-foot wide x 5-foot tall screen. Each [...]

Duke Multi-touch Wall Development - Hardware Part 1

September 15, 2008 (11:00) | Duke Multi-Touch Wall | No comments

RENCI‚Äôs initial foray into this area of research has taken the form of the 13.5-foot wide x 5-foot tall multi-touch visualization wall that was installed at the RENCI Duke Engagement Center in the beginning of May 2008. The wall sits at the end of the Engagement Center’s primary collaboration space:

This 6-projector (2 tall x 3 [...]