Xerox Corporation

Terry C Wells

David E Rumph

Thomas C Rich

Michael E Farrell

David C Robinson

Dennis Lee Venable

Jon S McElvain

James E Bollman

Phillip J Emmett

William Samuel Jacobs

Susan Evans

John P Monahan

A system and method are disclosed for an image processing system including a threaded scheduler providing compact and efficient dataflow as a pipeline management and data flow layer.

Image processing system and method employing a threaded scheduler

A method and system for determining chromatic content of a page of an electronic document. Object level color analysis is performed on a page of the electronic document to determine whether the page is chromatic, achromatic or has highlight color, based on the object level color analysis. The page is then classified as chromatic, achromatic or highlight color, based on the results of the determination.

User configured page chromaticity determination and splitting method

A method of identifying color mismatches for objects having different rendering intents within a print job prior to printing, includes identifying all objects within the print job, each object's type, rendering intent and all source colors associated with it; for each object in the print job, transforming each object's source colors using a prototypical color transformation; identifying sets of transformed objects having source colors that match within a first tolerance; transforming all transformed objects using a target printer's color space; identifying any of the transformed objects in each set that do not match within a second tolerance level; identifying any object types within the group of mismatched objects having at least two different rendering intents; selecting one of the rendering intents in accordance with a predetermined criterion; and assigning the selected rendering intent to at least one other instance of that object type.

Method for prepress-time color match verification and correction

A computer-implemented method of matching color elements for objects having different source color definitions within a print job prior to printing, includes identifying all source colors to be printed within the print job and object type associated with each instance of a source color; identifying any source colors having at least two different source color definitions; for each source color having at least two different source color definitions, selecting one of the source color definitions in accordance with a predetermined criterion; and assigning the selected source color definition to at least one other instance of the source color for that object type. The predetermined criterion may include for each source color having at least two different source color definitions for the same object type, assigning the selected source color definition to all other instances of the source color for that object type.

A method for correcting a white line artifact between low and high frequency printed pixels. A printer may be able to print either a high or low frequency halftone pixels in some locations, but may be able to print only high frequency halftone pixels in other locations, the latter known as out of phase locations. If the image data is in run length encoded form, and the printer tries to print a low frequency pixel in an out of phase location, no pixel will be printed in that location and a white space results. The remedy is to test at the beginning and end of low frequency runs bordering high frequency runs. If the first (last) low frequency pixel of an original run is in an out of phase location, a one pixel run of the high frequency screen and of the low frequency color is added before (after) the original run, and the run length of the low frequency run is decreased by one pixel.

Method for half tone phase matching at run boundaries

A method of determining whether a page to be printed on a color printer will actually be entirely printed in one colorant, usually black, and if so, automatically omitting whatever processing steps are unnecessary as a result. Determining if the page is monochrome can be done either by (1) including a signal in the PDL or by a signal from the user or by (2) inspecting each element of the page to determine if all elements are specified to be printed in the same one colorant. If either is true, then various color operations such as trapping, color conversion to any other color, and color correction for non-selected colors can be automatically omitted.

Growing community of inventors

Long Beach, CA, United States of America

Terry C Wells