Video tablet based on stereo camera - human-friendly handwritten capturing system for educational use

We are developing a capturing system to get handwritten sequential coordinates of a pen movement by using two video cameras which observe a writing pen. We call this system "video tablet". At first, sequential images are obtained through the video cameras. Next, our system estimates coordinates of handwritten positions by using a color marker in each image. For extracting the color marker, we use uniform color space. Through these operations, our video tablet system can get handwritten sequential coordinates by using stereo camera method.