A printing apparatus is adapted to receive print data specifying a color of an object to be printed with RGB values and specifying a type of the object as one of a text object, a graphic object and an image object. A print processor is operable to generate black image data from a set of the print data...http://www.google.com.au/patents/US7605946?utm_source=gb-gplus-sharePatent US7605946 - Printing apparatus increasing black density of one color of text or graphic object
