That looks like a very useful tool. I wonder what platform that would require. I can\'t quite imagine how the system could be presented to users through the internet.
One more question / problem... Does the system recognize the age of the image? It occured to me that you could be looking at an image of the Cathedral taken 25 years ago, right next to one taken last summer. For some objects it\'s not that important, but for others it might make a big difference. Pre- and Post-renovation pictures overlapping? I wonder if that would happen.