Reminds me of the work by Johnny Lee on projector calibration. His appears to be a bit faster.

http://johnnylee.net/projects/thesis/

According to this page, it's related work:

"This project is an update on a previous rig I did in 2011. The original project was inspired ("Reverse-engineered") from a paper published in 2004 by Johnny Chung Lee"

For a more technical description of the best algorithms to do this (and more advanced compensation) automatically, see:

http://www.cs.columbia.edu/CAVE/projects/pr_any/

BTW, these algorithms have been well understood and described by the research community for many years now. I think some companies targeting the high-end segment have incorporated some of these techniques, but I'm not sure why it's not filtered down into low-end consumer tech yet.

Actually, I think there's easily a startup or two in using your smartphone to calibrate a projector. The math would only have to be slightly modified, and if you could make this process seamless, it would be pretty cool.

I almost don't see why this can't be realtime. I imagine from here, all you need to do is throw more computing power at it? It's very cool. Imagine this plus a head-mounted pico-projector - any scrap of paper or wall could become an interface. Very excited about this technology.

It can be done in real time. Here is a demonstration from Float4 Interactive : http://www.youtube.com/watch?v=q_YOTZ4MCuA

You might also be interested to see a tree projection mapped: http://www.kimchiandchips.com/littree.php

Doesn't really need an active board. You could have a camera + projector and a board with fiducal marks.

Really awesome technology, unfortunate soundtrack to the _entire_ video.