Hands-on sharing: collaborative document manipulation on a tabletop display using bare hands

Working on electronic shared documents on a tabletop display is an effective form of collaborative work, which is likely to become a common practice in the future. A limiting factor in using tabletop displays at present, however, is their lack of support for multiple direct input by several users, or their reliance on expensive devices for supporting multiple user inputs. This paper describes a simple set of hardware and software solutions for creating a back-projection tabletop display with bare hand input mechanism to allow users to gesture at and select positions in a shared collaborative document. The system provides for a mixture of private and public workspaces for each collaborator.