The whiteboard recorder keeps a history of changes to an office white board as its owner adds to it and erases from it. It works by taking continuous video from a stationary camera pointed at the white board. The program filters out persons moving in front of the white board, and saves a minimum set of whiteboard history images by analyzing changes to the board and by following some simple rules. A Tcl interface to the Xt intrinsics and the Athena widget set has been implemented for the graphical user-interface code. Simple applications that use the default set of media processing modules are written as Tcl scripts.
More complicated applications require linking in additional modules to the default set.
To access audio and video devices unique to each particular brand of workstation, special device interface modules were developed. Sun's audio hardware and software is used for audio input and output. The Digital X server was used for video display. Digital's audio hardware and AudioFile software were used for audio input and output. There are currently 8 users of the environment in the Telemedia, Networks, and Systems group , four graduate students and four undergraduates.