I discovered Photoshop will indeed open a really really big Tiff file. It will not save it, so all you can do is look at it or scale it down to save it.
We flew the University of Oklahoma campus at a crazy high resolution and we have it in a 3D model or a straight down (nadir) ortho-photo. The print department of the university wants to print it a 40x60 and they wanted a 400 DPI image. OK, no sweat.
I did some quick calculations and figured if I output a 1/4 of full resolution image that would be about right. I was off by a lot. It took a long time to output the file and I thought Photoshop was locked up trying to open it. I went to eat dinner and cam back in my office and it was open.
The photo above is the screen capture of the image size information box in Photoshop.
Remember this is just 1/2 the full resolution. It is a part of the football stadium end zone.
175 Gig is a little big for their needs.
Next we want to take a small part of the image in 3D and have a 3D printer print a model of it. I have no idea if anyone would want an accurate 3D model of a city or campus, bet we can do it.