1. A computer-implemented method for creating an image product by accurately grouping faces, comprising: training classifiers between pairs of face groups in an initial set of n* face groups by a computer processor, wherein the initial set of n* face groups comprises a plurality of face images, wherein each of the initial set of n* face groups comprises one or more face images in the plurality of face images, wherein n* is a positive integer bigger than 1; classifying the plurality of face images by n*(n*−1)/2 classifiers by the computer processor to output binary vectors each associated with one of the plurality of face images; calculating a value of a similarity function for each pair of face images in the plurality of face images using the binary vectors associated with the respective pair of face images; grouping the plurality of face images into modified face groups by the computer processor based on values of similarity functions associated with different pairs of face images; and creating an image product based at least in part on the modified face groups.