1. A system for determining a measure of similarity between an image X and an image Y, the system comprising: a processor; and a non-transitory computer readable storage medium having computer readable instructions stored thereon, causing the processor to: (a) apply a multiresolution decomposition to the image X, producing an approximation subband containing main content of the image X and detail subbands containing fine edges of the image X; (b) apply said multiresolution decomposition to the image Y, producing an approximation subband containing main content of the image Y and detail subbands containing fine edges of the image Y; (c) determine an approximation similarity measure, characterizing similarity between the main content of the image X and the main content of the image Y, comprising processing the approximation subband of the image X and the approximation subband of the image Y; (d) aggregate the detail subbands of the image X, producing an aggregate for the image X; (e) aggregate the detail subbands of the image Y, producing an aggregate for the image Y; (f) determine an edge similarity measure, characterizing similarity between the fine edges of the image X and the fine edges of the image Y, comprising processing the aggregate for the image X and the aggregate for the image Y; and (g) determine the measure of similarity between the image X and the image Y, comprising processing the approximation similarity measure and the edge similarity measure.