FlashLight - Optical Communication Between Mobile Phones and Interactive Tabletops
Mobile phones can be used as mediators between users and interactive tabletops in several scenarios, including authentication and the sharing of information. Existing radio-based methods such as WiFi or Bluetooth offer a high-speed communication channel, but have serious limitations regarding the tabletop-phone-human interaction. They are not able to locate mobile phones placed on the surface, often require fairly complex coupling procedures for establishing connections, and are potentially vulnerable to eavesdropping attacks. In this paper, we present a method for establishing a bidirectional communication channel between mobile phones and vision-based interactive surfaces utilizing the built-in flash-light and camera of mobile phones and the screen and camera of vision-based tabletops. We establish an entirely visual, secure and bidirectional communication channel at a speed superior to previous vision-based approaches, enabling users to establish connections and transfer data to and from interactive surfaces using ordinary out-of-the-box hardware.