4. A system for ranking images retrieved in response to an image search, comprising: a general purpose computing device; a computer program comprising program modules executable by the general purpose computing device, wherein the computing device is directed by the program modules of the computer program to, receive a set of images in response to an image search; specify examples of images with image characteristics sought to be found; extract features based on image characteristics of each of the set of images received in response to the image search and the specified example images; learn one or more rules to find images of the desired visual characteristics based only on the features of the visual image characteristics of the example images selected by a user, wherein each rule is based only on a learning distance metric that computes a score for each image of the set of images received that indicates how similar each returned image in the set of images is to the selected example images with image characteristics sought to be found, and wherein learning the one or more rules for ranking images is based on a set of distance metrics that are used to represent the distance of any given image to any other given image and wherein the distance metrics comprise the quadratic distance between the image histograms of two images, and the distance in histogram entropy between two images; weight the features of each of the images of the set of images; rank the images of the image set based on one or more learned rules; and display the ranked images of the image set to a user.
7. The system of claim 4 further comprising a user interface which displays the ranked images of the image set and provides positive and negative example images for the user to choose to speed the learning of the rule.