Generation of a color dropout function for use in electronic color dropout

The present invention relates to document scanners and, more particularly, to a method and apparatus for functionally transforming a color image into a gray scale image in which the specified color is eliminated in business documents produced therefrom. 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 value according to a color dropout function; obtaining a gray scale value different from the identical gray scale value for the remaining portion of the image according to the color dropout function; and thresholding the gray scale values obtained from the previous steps to obtain a binary image that substantially eliminates color classification error which retains character integrity by a functional transformation that suppresses color fringe artifacts.