1. A method of processing information signals, the method comprising the steps of: extracting color information from an information signal in order to generate a color distribution of the information signal; and generating an achromatic pattern map for the information signal using the color distribution generated from the information signal, wherein the achromatic pattern map includes a plurality of dominant colors of the color information each mapped into corresponding gray scale levels, and wherein the dominant colors are mapped into the gray levels based on the pixel areas associated with the dominant colors.