AUTOMATIC EVENT RECOGNITION AND CROSS-USER PHOTO CLUSTERING

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for automatic event recognition and photo clustering. In one aspect, methods include receiving, from a first user, first image data corresponding to a first image, receiving, from a second user, second image data corresponding to a second image, comparing the first image data and the second image data, and determining that the first image and the second image correspond to a coincident event based on the comparing.