SUPERIMPOSING a historic photo on an up-to-date snap of the same scene is a neat way to bring history to life, as the website historypin.com demonstrates.
If you want to take a modern photo that will contrast effectively with its historical counterpart, though, you need to ensure it is taken from the same spot, and with the same zoom level. If you don’t, the combined picture ends up looking disjointed, with roofs, walls and roads poorly matched.
If these cobbles could speak (Image: Historypin.com/Mirror Pix)
Help is at hand, however, in the form of new software for digital cameras that helps people get their shot-framing spot on. Frédo Durand and Soonmin Bae at the Massachusetts Institute of Technology in Boston, with Aseem Agarwala of Adobe Systems in San Jose, California, turned to a technique called visual homing to come up with an answer (ACM Transactions On Graphics, DOI: 10.1145/1805964.1805968). Visual homing is used in robotics to send a machine to a precise location, such as a charging station.
The team’s software runs on a laptop linked to a digital camera. The software compares the camera’s view to a preloaded historical scene and provides instructions to adjust the camera’s position and zoom to best match the scene.
The laptop is a temporary measure, however: "We envision the tool running directly on the camera," the team says.