"Computational rephotography is a fancy name for photos taken from the exact same viewpoint as an old photograph. Actually, that’s just rephotography. The “computational” part is when software helps out. [...] At Flickr and a site called Historypin, you can see the old shots lined up over the new, like a window into the past.
Researchers at MIT have found a way to automate the process. Currently, they use a laptop to do the heavy lifting, but the software could just as easily sit inside a camera. In fact, that’s the plan. The system compares the scene in front of the camera with a historical photograph. It then works out the difference between the two and gives the photographer instructions along the lines of “up a bit, left a bit more.”
According to an abstract on rephotography, it is a lot more complicated than it seems. In lining up the images you must consider 'six degrees of freedom of 3-D translation and rotation, and the confounding similarity between the effects of camera zoom and dolly.'" -- Charlie Sorrel
[from Wired]
