Tele-Graffiti

Tele-graffiti is a technology that allows two or more users to communicate remotely via hand-drawn sketches. What one person writes at one site is captured by a video camera, transmitted to the other site and displayed there using an LCD projector.
The system was developed at Robotics Institute of Carnegie Mellon university, Pittsburg. The system comprises of a digital camera, a high resolution LCD projector to project the received image, a mirror to reflect the projected image onto the paper, fixture to hold these devices in position and a writing pad to fix the sheet of paper on the top of the table at every station.
The user can write on a regular piece of paper with a pen at his desk. The sketch or writing on the paper is captured by the camera and transmits the digitized image to the receiving end through a data link.
The image can be transmitted over the internet or local area network. The software architecture of system runs on Linux  and has four threads the drawing thread, the paper tracking thread, sending thread and receiving thread.
Tele-graffiti has various applications. It can play an important role in remote education and remote designing.
It can also serve as a substitute for internet chat. The advantage of the system is that non-computer people can use it. .