Halftone screens encoding signatures
AssigneeHewlett-Packard Development Company, L.P.
InventorsGideon Amir, Tadej Turk
Life of this patent
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Abstract
In an example, a method includes, at least one processor, in response to each of a plurality of requests, determining a halftone screen. Determining the halftone screen comprises encoding a signature pattern in the halftone screen, and halftone screens for different requests may be encoded with a different signature pattern. The halftone screen may be arranged such that, when applied to image data to provide a printed output, the pattern is discernible therein to provide a signature for the printed output.
Claims18
A method comprising, by at least one processor:
- in response to each of a plurality of requests, determining a halftone screen, wherein determining the halftone screen comprises encoding one unpartitioned signature pattern into the halftone screen, and halftone screens for different requests are encoded with a different one unpartitioned signature pattern;
- and
- applying the halftone screen to image data, the halftone screen being arranged such that, when applied to the image data to provide a printed output, the one unpartitioned signature pattern is discernible therein to provide a signature for the printed output, wherein applying the halftone screen to the image data includes:
- associating a pixel of the halftone screen with a pixel of the image data, comparing a pixel value of the image data with a threshold value of the pixel of the halftone screen, and
- determining print instructions for the pixel of image data based on a result of the comparison.
A method comprising, by at least one processor:
- in response to each of a plurality of requests, determining a halftone screen, wherein determining the halftone screen comprises encoding a signature pattern into the halftone screen, and halftone screens for different requests are encoded with a different signature pattern;
- and
- applying the halftone screen to image data, the halftone screen arranged such that, when applied to the image data to provide a printed output, the pattern is discernible therein to provide a signature for the printed output;
- and
- preventing selection of the halftone screen or signature pattern in response to a subsequent request.
Dependencies are inferred from the claim text.