Grab a friend and a nearby tablet computer and try to draw a picture together in the computer’s finger painting program. Try it, but it won’t work as you may expect it to because the computer can’t discern you from your friend.

University of Manitoba computer scientists in the Human-Computer Interaction laboratory are the first to develop a lightweight and elegant software solution that leaps over this hurdle: They created See You, See Me. This software is a boon to computer makers like Microsoft who want to develop table top computers and wall displays that many people – like school children in a classroom or architects at a drafting table -- can simultaneously interact with.

The research was done by touch-interface researcher Pourang Irani, an associate professor of computer science who developed the Lens Mouse, and his graduate students Hong Zhang, Barrett Ens, Xing-Dong Yang and Hai-Ning Liang. Zhang will present the research at one of the field’s premiere scientific conference in April in Austin, Texas.

See You, See Me enables computers to distinguish between user touches with near-perfect accuracy; and if a rare mistake occurs the software provides a quick remedy. It uses the finger orientation extracted from the user’s hand’s shadow to determine where people are and to keep track of who is doing what to the screen.

The video attached to this release shows how easy it is to break playing conventions in a game of tic-tac-toe with current technology, and how Irani’s innovation solves the problem and clears the way for a bevy of better multi-user applications.

“Without knowing ‘who’ is doing ‘what’, a multi-user system may not easily enable its simultaneous use by more than one user at a time. Until this problem gets resolved, ‘true’ multi-user collaboration will not take off”, says Hong, who recently defended his thesis.