Section: New Results

Direct and indirect multi-touch interaction on a wall display

Multi-touch wall displays allow to take advantage of co-located interaction (direct interaction) on very large surfaces. However interacting with content beyond arms' reach requires body movements, introducing fatigue and impacting performance. Interacting with distant content using a pointer can alleviate these problems but introduces legibility issues and loses the benefits of multi-touch interaction. We introduced WallPad [30] , [11] , a widget designed to quickly access remote content on wall displays while addressing legibility issues and supporting direct multi-touch interaction (Figure 1 ). To support multi-touch on such a wall display, we developed a custom system using front diffuse illumination and 4 cameras. Our system can detect 50+ simultaneous contacts with a precision between 3 and 5 mm.

Figure 1. A user creating a WallPad (a). Another using two WallPads to select (b) some text (c) and click (d) on Copy/Paste buttons (e) beyond reach. A third user accessing a color palette located at the bottom of the screen through a WallPad (f).