1. A method performed by data processing apparatus, the method comprising: displaying, in a user interface, a plurality of duplicate images, wherein each duplicate image includes associated metadata comprising one or more image attributes; obtaining a selection of a single image from among the plurality of duplicate images; generating, for the selected image, aggregated information based on the metadata associated with the plurality of duplicate images, wherein the aggregated information includes one or more aggregated attributes, at least one aggregated attribute generated based on image attributes that are associated with at least two of the duplicate images and are of a same type; and storing the selected image together with the aggregated information on data storage accessible to the data processing apparatus.