'Global camera' links photos taken by thousands
- 11 August, 2011 08:10
The digital photographs you take on your next holiday could become part of a 3D image of the whole world. Cornell University's Noah Snavely stitches them together with software he's developed that he calls a "global camera." For his work he was named as one of eight Microsoft Research Faculty Fellows for 2011.
Every minute tourists all over the world shoot thousands of photographs. Snavely, an assistant professor in the Computer Science Department at Cornell University, said he "wants to make use of all the images taken in the world."
The aim is to organize the millions of unrelated pictures taken by thousands of individuals into one big visual record of the world. Snavely's main source is Flickr, the online service where people upload, store and share their photos.
Snavely extracts the data from these images and uses computer-vision algorithms, as well as spatial information such as geotags, to put them together.
He and his group are building a database of thousands of landmarks worldwide. Among those already in the database are sights such as the Eiffel Tower in Paris or Trafalgar Square in London, which according to Snavely are both among the most-photographed spots in the world. The computer scientist says the ultimate goal is to build a 3D model that encompasses the entire world.
"Imagine how all photographs taken from London over time would show how the city changed," he said. According to Snavely, a possible application for visual models of cities could be in planning urban infrastructures or enhancing maps.
The photographs could also be used for scientific purposes, Snavely said. For example, cellphone cameras could be used to monitor crop growth in developing countries. Governments or NGOs could use this data.
As probably not a huge number of people would take pictures of wheat fields, Snavely has come up with a way to encourage them to do so. "PhotoCity" is a game where users raise their score by uploading new pictures of certain landmarks. "With a game like that you can guide the global camera," Snavely said.
The research has already been transformed into commercial products to some extent. Microsoft's tool set "Photosynth" was inspired by his work. In five to 10 years he thinks there will be more applications like this on a more global scale.
The Microsoft Research Faculty Fellowship boosts his research in that area. The fellowship includes a cash award of US$200,000 given over two years. One of the things Snavely wants to do with the money is expand his group, which is currently just him and four graduate students, by hiring a postdoc. "However, what is even more important than the money is that the award is very prestigious," Snavely said.
Snavely received his Master of Science and his Ph.D. in computer science and engineering from the University of Washington in Seattle, after earning a Bachelor of Science in computer science and mathematics at the University of Arizona in Tucson.