Just a quick reply as I'm passing, sorry I'm in a dash, so to speak

The wall, as I think I mentioned in the thread namvet supplied, is a real photo, that I made a copy of desaturated it and used that as an alpha channel. I think I may have used the same desat' version to run the dis[place filter on the images too. Not 100% about that though.
Seems like you have a few ideas to start with anyway. It would be good if you came back here with what you have managed to produce and then we can take it from there, if needed, to take it to the next level

Good Luck
Tao