Freehand interaction with a paper-based input interface

Graphical user interfaces may sometimes not be fully comfortable, because they require oculomotor coordination and relatively precise mouse movement. While physical interfaces can be the right choice for purpose-specific appliances, they become less practicable in the case of interfaces for software tools, since each program would need its own physical interface. This paper presents a gesture input approach based on a paper interface, appraising its efficiency and investigating the user acceptance level. Through fingers, users can operate interface controls either drawn by themselves or provided in ready-to-use pre-printed sheets. The implemented prototype, based on computer vision, relies on a simple and cheap webcam, and controls consist of sliders, buttons, knobs and trackpads. Experiments have shown that the proposed approach is practicable in terms of both performance and positive reception by users, although some inherent problems of vision-based systems must be taken into account.