1. A method of delivering an image, comprising: receiving a request for an image; determining by a processor a variation of quality signature of the image, wherein the variation of quality signature of the image comprises a plurality of element signatures, comprising: generating a reduced version of the image; generating a plurality of reduced distorted images, wherein each reduced distorted image is formed by: applying a different level of distortion to the image, and wherein the different levels of distortion are applied using a single compression algorithm; and generating a reduced version of the image after the corresponding level of distortion is applied; and determining the plurality of element signatures, wherein each element signature corresponds to one of the plurality of reduced distorted images, and wherein each element signature measures a degree of similarity between the reduced version of the image and the corresponding reduced distorted image; categorizing by the processor the image into one of a plurality of clusters of images, wherein the categorization is based on a similarity between the variation of quality signature of the image and one or more other variation of quality signatures of one or more other images within the plurality of clusters of images; and delivering a distorted version of the image based on the categorization.