The invention determines the degree of similarity between a target image and each of a plurality of reference images. The measure used for the degree of similarity between images is based on the human perceptive system, so that images that appear to a human to be similar in color have a higher similarity...http://www.google.com/patents/US20010053249?utm_source=gb-gplus-sharePatent US20010053249 - Color quantization and similarity measure for content based image retrieval
