If you have seen the Blade Runner movie, you will know what I am talking about: A blade runner logging into his computer, checking photo evidence found. Zooming into the photo (we can do that, right?), checking different parts of the photo and (behold!) zooming on the various objects, so the flat image transforms into 3D and you can move inside the photo as you would do in any 3D space. See the Esper photo analysis video from the Blade Runner movie (alas, not embeddable). Also, see how the Esper machine photo analysis would work like in the Blade Runner video game for the PC.
Now, check this 2D photo to 3D explorable space transformation developed by the researchers at Carnegie Mellon University. The video is quite old – from 2006 to be exact – and I know the computer algorithm just “fills in” the missing pixels, but nonetheless, it is interesting. I am sure there has to be plenty of amateur online apps nowadays just waiting to transform your ordinary photos into something resembling the abovementioned example (there are lots of examples on the YouTube). Imagine, you have a high tech (and pricey) lab set up for the photo and video analysis. You would certainly like to do the same thing the blade runners did. And I guess there already exist similar technologies available at the intelligence agencies or (modern) police forces.