Automated system for print quality control
AssigneeThe Analytic Sciences Corporation
InventorGeorge Stephen Zabele
Life of this patent
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Abstract
A system and methods for controlling print quality of a printed product of a printer, which may comprise an image acquisition unit for acquiring an electronic test image of printing on the printed product after printing by the printer, an image processor for comparing the test image of the printing with a prototype image of desired printing and determining a match between the printing on the test image and the printing on the prototype image, and means for generating an alarm representative of a print quality problem when the match between the printing on the test image and the printing on the prototype image does not satisfy a predetermined condition. The printed product is not required to include any reference marks.
Claims16
A system for controlling print quality of a printed product of a printer, comprising:
- an image acquisition unit for acquiring an electronic test image of printing on said printed product after printing by said printer;
- an image processor for comparing the test image of the printing with a prototype image of desired printing and determining a match between the printing on said test image and the corresponding printing on said prototype image;
- said image processor including means for performing quality assessment of a printed product that includes any differently ordered sequences of a group of pages that each contain a different arrangement of printed pixels, during printing by said printer;
- and
- means for generating an alarm representative of a print quality problem when the match between the printing on said test image and the printing on said prototype image does not satisfy a predetermined condition.
A method for controlling print quality of a printed product of a printer, comprising the steps of:
- acquiring an electronic prototype image of desired printing on said printed product, wherein the step of acquiring a prototype image includes acquiring, from said printer as said printed product is being printed, a dynamic prototype image defining an appearance of said printed product for comparison with said test image during printing by said printer;
- acquiring an electronic test image of actual printing on said printed product after printing by said printer;
- electronically comparing said test image with said dynamic prototype image and determining a match between the printing on said test image and the printing on said dynamic prototype image;
- generating an alarm representative of a print quality problem when the match between the printing on said test image and the printing on said dynamic prototype image does not satisfy a predetermined condition;
- and
- dynamically generating an exception mask from the dynamic prototype image acquired in the step of acquiring, said exception mask defining transition regions of said prototype image, and further including the step of ignoring mismatches in said transition regions of said prototype image defined by said exception mask.
A system for controlling print quality of a printed product of a printer, comprising:
- an image acquisition unit for acquiring an electronic test image of printing on said printed product after printing by said printer;
- an image processor for comparing the test image of the printing with a prototype image of desired printing and determining a match between the printing on said test image and the printing on said prototype image by comparing each of a plurality of overlapping multi-pixel blocks of the prototype image with a different, corresponding set of locally shifted multi-pixel blocks of the test image and evaluating a best match between each of the blocks of the prototype image and the blocks in its corresponding one of the sets;
- and
- means for generating an alarm representative of a print quality problem when the best match between one of the blocks of said test image and one of the blocks of said prototype image does not satisfy a predetermined condition.
A system for controlling print quality of a printed product of a printer, comprising:
- an image acquisition unit for acquiring an electronic test image of printing on said printed product after printing by said printer;
- an image processor for comparing the test image of the printing with one prototype image of desired printing and determining a match between the printing on said test image and the printing on said one prototype image, said image processor comprising:
- means for generating, from said one prototype image alone and using morphological filtering operations, an exception mask corresponding to said prototype image, said exception mask defining transition regions of said prototype image;
- and
- means for ignoring mismatches in said transition regions of said prototype image defined by said exception mask;
- and
- means for generating an alarm representative of a print quality problem when the match between the printing on said test image and the printing on said prototype image does not satisfy a predetermined condition.
Dependencies are inferred from the claim text.