Locating Physical Interface Objects on Interactive Surfaces

Pin&Play has enabled a new type of surface-based physical user interface, characterised by dynamic arrangement of interface objects on a surface area. Previous work has shown that this affords rapid re-arrangement of the spatial layout of interface objects, for example in adaptation to user preferences, but the Pin&Play system did not support tracking of object locations on the surface. In t his paper, we investigate and compare two practical location techniques for interactive surfaces that are based on external sensing: detection of surface events using load sensors, and camera-based detection using object beacons.