1. A method comprising: locating, for each of a plurality of patches in a first image, a corresponding similar patch in a second image based on one or more similarity measures; determining, by one or more computing devices, a score for each of the plurality of patches with respect to its corresponding similar patch, determining the score comprising determining one or more of a divergence metric or a distance metric; selecting at least one saliently different crop in the first image based at least in part on the determined scores for the plurality of patches, the saliently different crop highlighting a salient difference in the first image relative to the second image; and generating at least one thumbnail image for the first image based at least in part on the at least one saliently different crop.