A method for performing color dropout on a digitized document, the method comprises the steps of obtaining color values from the digitized document for background and a color of interest to a user; transforming the color values of the background and the color of interest into an identical gray scale...http://www.google.com.au/patents/US6823081?utm_source=gb-gplus-sharePatent US6823081 - Generation of a color dropout function for use in electronic color dropout
