Portable whiteboard system with vision input We present a novel whiteboard system that uses one or more active input devices. The system is especially suitable for situations in which several users provide input on a large writing surface which also serves as a projection surface. That surface can have general orientation. We have implemented a system that uses an inexpensive, infraredemitting stylus and an offtheshelf videoconferencing camera fitted with an IR transmittingvisible blocking filter to capture handwritten strokes. The system uses a calibration method that uses projective mapping thus allowing offaxis camera placement. We also propose a selfcalibrating system in which the capture device shares its optical system with the projector. In a system with multiple local users the question of who wrote what becomes relevant. Therefore, we address the question of attaching identity to stroke information.

Tabletop Human Computer Interface to Assist Elderly with Tasks of Daily Living Old age is associated with declines in vision, hearing, sensory function, motor function, and cognition. These declines make managing activities of daily living harder. Computer mobile devices could help, but many elderly people find the interface too small and navigation too complex. A larger computer interface in a natural setting, such as a tabletop, could provide a more usable interface and be able to provide better assistance for some elderly people. The purpose of this project was to develop a prototype human computer interface that projects images onto a tabletop, uses an imaging system to identify hand position over the tabletop in relation to the projected image, detects menu selections of the hand over projected buttons, and takes actions, such as displaying the selected next menu. A prototype was developed using custom LabView programs for generation of images of menu selections to be projected, image processing and control of the system. Hand recognition was simplified by having the user wear a white glove with a black square on the back for the imaging system to search for. Button selection was recognized by holding the hand over a projected menu button for several seconds. The prototype function showed promise. Further testing and development will be necessary toward wider implementation. Such a projected tabletop human computer interface may improve computer derive assistance for elderly people compared to mobile or computer display interfaces.