A wonderful finished DIY project that allows automatic and quick calibration of video projection.
The video below demonstrates the ability of calibrating videos automatically with the screen. It gives live examples of using one projector, two and even proving it with a 3D model.
Instead of me attempting to explain the entire process, this video is both informative and fascinating. I bet many DIY and home cinema buffs would see the potential of such a project. You can find further explanation in the creators’ PDF (here).