Blue and green street signs, tall double-paned windows, balconies enclosed with iron filigree, and a distinct lamppost style: the keys to Parisian charm, as calculated by an algorithm.
Google Street View/Carl Doersch et al.
When the directors of Ratatouille set out to create the look and feel of Paris in computer-generated art, they faced the same question that faces any artist tasked with capturing any particular place: What is it -- visually -- that makes this place this place? As co-drector Jan Pikava explained in the book The Art of Ratatouille, "The basic question for us was: 'what would Paris look like as a model of Paris?', that is, what are the main things that give the city its unique look?" To find out, his team had to (pdf) "run around Paris for a week like mad tourists, just looking at things, talking about them, and taking lots of pictures." The results looked very, well, Parisian, just as the artists had hoped.
What was it about Paris they had homed in on? What is it about any city that gives it its distinct look?
Computer scientists at Carnegie Mellon University and the Ecole Normale Superieure in Paris have built an algorithm that uses images pulled from Google's Street View to do much what Pixar's artists did: Find the small details that appear frequently in Paris and -- crucially -- do not appear in other cities. In other words: You can't evoke Paris with just the Eiffel Tower and the Arc de Triomphe. You need to find the distinct visual cues that emerge block after block, street after street. In Paris, the algorithm ferreted out the city's blue and green street signs, tall double-paned windows, balconies enclosed by iron filigree, and, as Pixar captures above, a particular lamppost style. Paris's je ne sais quoi, is, to the contrary, quite knowable after all -- discoverable by both artist and algorithm.