1. A method for designating a local representative color (LRC) values of a color image, comprising the steps of: (a) dividing a color image into equal blocks; (b) building color histogram for each blocks and designating the maximum color value of a color histogram as a LRC value of a corresponding block if the maximum color value meets a first condition; and (c) repeating steps (a) and (b) until the last block of the image is processed.