The MagicBoard

The MagicBoard augments a perfectly ordinary white board with electronic capabilities, via a video projector and a pan / tilt / zoom camera.

The user works on the board as in the usual way, drawing or writing with ordinary marker pens. Whenever she chooses, the user can "grab" an electronic copy of the things that have been drawn or written with the marker pen. This copy is projected back onto the board, precisely overlaying the original markings with the appropriate colour. The physical ink may then be erased and the electronic version manipulated on the board's surface: it can be duplicated, moved, enlarged or reduced, printed, or hidden for a moment before being recalled. Meanwhile, the user may add to her designs with the marker pen as before. At any time, these new markings can be turned into digital form to merge with the electronic version of her work.

The video-clip on the left (19.6 Mb) shows the system in use. If your browser can't play the video, either download the quicktime player, or try an mpeg encoded (36.9 Mb) version of the video. Set your monitor to "thousands" of colours for best results.
  • Two people are using the board for brainstorming. They begin a drawing with their regular marker pens.
  • They decide to duplicate their initial drawing and so, by gesturing at a menu projected in the top right-hand corner of the board, obtain a selection pointer. This pointer tracks a finger to the edge of the drawing. A pause for half a second causes the pointer to change into a projected selection box, which is then dragged around the whole of the drawing. Note that all mode changes are performed by pausing for half a second.
  • An initial instantaneous low-resolution grab is executed by the system so that the user can immediately move the copy of the drawing.
  • On user's request, by selecting a command from the popup menu, a high resolution grab is executed. The pan-tilt-zoom camera is driven to grab the selection divided in 4 parts.
  • The drawing is then completed with both physical and electronical ink.
  • Finally, the user requests a global copy of the board. This copy is shown below.

Note that the electronic ink does not show up very well in this video due to technical difficulties in filming video projection. In the actual setting, the physical and electronic inks are comparable.

The image on the right is the result of the final capture in the above video clip. This is actually a very low resolution version of the captured image. A medium resolution version (40Kb, 900 x 675 pixels) is available, as well as the full resolution version (107Kb, 1800 x 1350 pixels).
If the capture is to be printed or processed by optical character recognition, the resolution can be increased by grabbing more images of the board. The image on the right is the result of a 6 by 6 mosaïquing of the image on the left (click on the images to get full resolution). The right image is also available at medium resolution (70Kb, 900 x 675 pixels), and at full resolution (340Kb, 3600 x 2700 pixels).
The systems runs on top of TclVision, a multi-platform interactive computer vision environment (MacOS / SGI IRIX / Linux / win2k). Our main workstation is a PowerMac 8600 (PPC 604 @ 350 Mhz). The system also runs (slower) on an SGI O2 (R10000 @ 150 Mhz).
The MagicBoard was developped in the Human-Computer Interaction group at CLIPS-IMAG laboratory in Grenoble, France. Developers François Bérard
Sébastien Annedouche
Benoît Loup
Michel Prodhomme
Yann Laurillau
Contributors Joëlle Coutaz
David Thevenin
Leon Watts
William Astier
Related work Pierre Wellner's DigitalDesk
Eric Saund's ZombieBoard
Created on June 19, 1999 by François Bérard, artwork from Gregory Barborini.
Last update July 19, 2001.