Portico Spreads Tablet Touch Beyond The Screen

Tablets that can respond not only to touchscreen contact but taps and motions in the area around them could deliver a combination of Microsoft Surface-style expansive gestures in a portable form-factor, if researchers have their way. Portico, the handiwork of three computer scientists at Intel, Microsoft Research and the University of Washington, uses a pair of pull-out webcams to track movement on the table the slate is resting on. That way, objects in the periphery of the tablet can interact with what's being shown on-screen.

According to Daniel Avrahami, Jacob Wobbrock and Shahram Izadi, the team behind Portico, the system gives a 12-inch tablet the touchable area of a 26-inch display. In their demonstration – which you can see in the video below – a ball rolled at the side of the slate is tracked and then converted into a virtual ball when it impacts the edge, the motion continued across the screen. However, there's more to it than simple gaming.

"The idea is to allow the interactive space to go beyond the display space or screen space" Wobbrock told Technology Review, suggesting that it could make for easier device interaction as our portable gadgets get smaller. "As devices continue to shrink, they compromise the screen space" he points out, "but with Portico you can reclaim the surrounding area for interactivity."

Portico uses the pair of cameras to calculate the height and position of objects around the tablet, using that information to figure out how the on-screen graphics should respond. Although the current prototype – which the trio will demonstrate at UIST 2011 next month – uses a two webcams on extendable arms, an alternative would be clip-on cameras or, even, a simple framework using a pico-projector to create the virtual desktop.