There are a zillion digital photos in the public domain and scientists have just figured out something very cool to do with them. A team from Google and the University of Washington have developed a fully automated way to create time-lapse videos of popular tourists landmarks using images from Flickr, Picasa and other sites. Here's how it works: first, the researchers sorted some 86 million photos by geographic location, looking for widely snapped landmarks. Next, the photos were ordered by date and warped so that all had a matching viewpoint. Lastly, each photo was color-corrected to have a similar appearance, resulting in uniform time-lapse videos (below).
The videos aren't just breathtaking, but also illuminating. For instance, they show glaciers receding, waterfalls evolving and skyscrapers sprouting (above), making them useful tools for geologists or builders. The science that went into the time-lapses is also interesting, as researchers combined various techniques in warping, stabilization and color normalizing to make it work. Many sequences contain over 1,000 images and took around six hours to render on a single computer. The best part is that even though it's a fun form of crowdsourcing, it doesn't require participants to do anything but be tourists.