8. A system comprising a computing device and at least one program module that together are configured for performed actions comprising: determining, by the computing device for each image in a set of images, facial recognition data that, for each face detected by the computing device in the each image, comprises a face identifier that uniquely identifies the each face, a set of facial feature descriptors, a face score that is based on an open/closed state of the each face's eyes and mouth and that indicates an overall quality of the face, and a face signature that, across the images in the set, uniquely identifies an entity that the each face represents; and grouping, by the computing device based at least on the face signatures and the face scores, images of the set into one or more groups, where each group comprises one or more images that each show a detected face that represents a same entity as that represented by any other detected face shown in any image in the each group.
9. The system of claim 8 where the grouping is further based on the face scores.