1. A computer-implemented method, comprising: performing face detection, using a processor, on a plurality of images to identify a plurality of faces; activating a subset of the plurality of faces, including by loading data associated with the subset of faces into a processing memory, wherein at least one of the plurality of faces is un-activated, including by keeping data associated with the at least one of the plurality of faces out of the processing memory; calculating a distance for each pair of activated faces, wherein the distance is associated with a measure of a similarity between a first face and a second face; clustering the activated faces into a plurality of groups based at least in part on the distances; reducing an amount of information loaded in the processing memory, including by modifying data associated with at least one of the plurality of groups; and after reducing, activating at least one un-activated face, including by loading data associated with the at least one un-activated face into the processing memory.