Document Camera Ink Capture System:
In May of 2005 Professor Patrick Mantey asked me to create a system for him
which could accept a live video stream from a document camera (pictured below)
and which would allow this captured video stream to be transmitted to students
via the internet at extremely low bit-rates. The idea behind the project
is that the only part of the video stream which is of interest is the inkings
made by the instructor. Therefore I created an application which at every
frame detects any new inkings made since the last frame. These inkings are
then made into a binary image, white for new ink, black for the rest of the
image. Since the majority of this binary image is black we can compress the
binary image with a high degree of efficiency. This compressed frame is then
transmitted to students where the original video is recreated. The document camera we are using can be seen to the left.
Below are two videos. The first shows an example of an input to our system, as recorded by the document camera. This input is what is seen by the professor as well as any students who are in the room with the professor watching the live feed. The second video shows the result of my algorithm, in other words what the students at remote locations would see.
As can be seen, the important parts of the document are transmitted to the student. All relavent information is recorded and the data is able to be highly compressed allowing for ultra-low-bandwidth transmission.
You may need to disable Firefox's NoScript extension to view the videos.
(Download the input video by clicking on this link, you may need to right-click and use "Save As" (25.5 MB))
(Or download the smaller version (8 MB))
(Download the results video by clicking on this link, you may need to right-click and use "Save As" (20.5 MB))
(Or download the smaller version (5.5 MB))