Pressure adds depth to displays

Researchers from the University of Toronto are proposing to add a new dimension to the clickable graphics that appear on computer screens: pressure.

The researchers' pressure widgets scheme takes advantage of pressure-sensitive input devices like tablets that sense not only the position of a pointing device, but also tilt and pressure to give computer interface elements, or widgets, new abilities.

The scheme offers a way to add pressure-based functionality to software using existing tablet input devices, and widens the potential functionality of devices that use a stylus as its main or only mode of input, according to the researchers. Today only a handful of graphics applications use pressure-based input.

In tests of pressure widgets that allowed test subjects to control a cursor along a vertical line, the researchers found that people are able to use as many as six different levels of pressure for discrete selection tasks, but that pressure is only useful if there is also continuous visual feedback.

The researchers' have also designed pressure widgets for controlling, navigating and annotating digital video.

The researchers are exploring ways to use pressure widgets for two types of tasks: discrete selection, like choosing a color from a palette, and continuous parameters, like opacity.

The pressure widgets scheme could be implemented immediately on devices capable of sensing pressure, like tablet computers, according to the researchers. The researchers presented in the work at the Association of Computing Machinery (ACM) Computer-Human and Interaction (CHI) 2004 conference in Vienna, Austria, April 24 to 29.