Dual-Mode Infrared Tracking of Tangible Tabletops

Abstract: On tangible tabletops, Tangible User Interfaces (TUIs) can signalize their identity, position, orientation, and state by active infrared light. This provides rich interaction capabilities in complex, dynamic scenarios. If TUIs have to transfer additional high-resolution information, many bits are required for each update. This has a negative impact on the overall update rate of the system. In this thesis, we present a new solution for providing TUIs with high number of states. Prototypical TUI concepts such as slider, ruler, and dials further motivate the benefit of high-resolution tracking. We depart from a device tracking overview and then show how tangible devices for tabletops typically use infrared (IR) emitters and a camera to send information about their position, orientation, and state. Since transferring many additional information bits via a normal camera-based tabletop system is not feasible anymore, we introduce next a new system setup that still offers a sufficiently high update rate for a smooth interaction. The new method can be realized as a tabletop system using a low-cost camera detecting position, combined with a low-cost infrared receiver detecting the state of each device. Since both kinds of sensors are used simultaneously we call the method “dual mode.” This method combines a camera-based tracking with the possibility to transfer a significantly high amount of states for each device.