Experiences Implementing and Using Personal Projected Displays

We have created a personal projected display called the Escritoire. Two projectors overlap to create a horizontal desk display, and two pens allow two-handed input. We describe the issues we encountered implementing this system and the results of experiments with single users working on their own and with pairs of users collaborating using separate desks. Cheap portable projectors form a display that fills the desk and also has a high-resolution region in front of the user. The display works under normal office lighting and front projection has not been a problem. Commodity 3D video cards can easily perform the necessary image warping, using planar homographies, to compensate for rough projector positioning. We describe various implementation issues with DirectX and OpenGL. Individual users were quickly able to use the system, and the colour and intensity mismatch between projectors was not a problem. For remote collaboration participants found an audio channel and shared desk surface to be much more useful than a video channel.