US Patent 7246880 Method for black pixel designation in document image data

Embodiments of the present invention are directed to a method of processing document image data for printing. The method comprises rasterizing all objects in the document image data into a bitmap format including designating black portions of the objects as composite black pixels. Color objects are identified in the document image data that contain color or are adjacent to color. All composite black pixel designations in the identified color objects are maintained as composite black pixel designations without substitution to true black pixel designations. Print data is generated in which the composite black pixel designations will be half-tone printed on a print medium as a portion of composite black ink and a portion of true black ink.