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US 5,923,821 AGranted
Digital image trapping system
AssigneeXerox Corporation
InventorsDavid Birnbaum, Tse-kee Chan, Bradley W. Smith, Fritz F. Ebner, Stephen F. Linder
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AssigneeXerox Corporation
InventorsDavid Birnbaum, Tse-kee Chan, Bradley W. Smith, Fritz F. Ebner, Stephen F. Linder
Estimating the term…
A system for trapping of a dark image object on a lighter colored background is disclosed. In a system using a page description language including overprint operators, black image areas (such as text, lines, graphic objects and the like) can be set to overprint colored background areas in a manner that eliminates rendered image defects including page-colored "halo" effect that can occur when the cutout background area underlying the black object is misregistered with the black object that was intended to cover the cutout area. In other systems, the present invention may be employed as a disabling of the undercolor removal system of a colored area that would otherwise be present under the black object. Systems using black plus at least one other toners or ink color (such as cyan, magenta and/or yellow or many other colors) can usefully employ the system of the present invention. The trapping system of the present invention may also be employed on an object-oriented basis, such that different image object types are trapped according to the system of the present invention and at least one other trapping system.
A method for preventing undesirable image artifacts from occurring in a border region between a black image area and a colored background area on an output image produced by a digital printing system, said printing system operable to render the output images in a black plane and at least one color plane and including a processor for processing a stream of imaging data including page description language file code for clearing the at least one color plane in a trap area corresponding to a portion of the black image area, said method comprising the steps of:
A printing system including a processor for preventing undesirable image artifacts from occurring in a border region between a black image area and a colored background area when rendering output images in a black plane and at least one color plane, said processor being operable to process a stream of imaging data including page description language file code for clearing the at least one color plane in a trap area corresponding to a portion of the black image area and an undercolor removal code, said printing system comprising:
A method for multimode trapping of images according to a plurality of object types so as to prevent undesirable image artifacts from occurring in border regions between image object areas and background areas having at least one color separation to be produced by a multicolor digital printing system, said method comprising the steps:
Dependencies are inferred from the claim text.