Image map based displacements is maybe one of the least explored ways in TG2 for displacing terrains.
Moodflow had some success with it, as well as Hannes IIRC.
A simple search for these would point you there.
The youtube video is meant for purchasers of the pack, since I demonstrate how to paint the canyon using the tgd-file I created.
So if you don't have the pack there is not much real use of it for you.
Anyhow, you can watch in fullscreen on the youtube site itself:
http://www.youtube.com/watch?v=zdgTEyNWWMkRegards,
Martin