Halftone imaging with reduced dot isolation
AssigneeHewlett-Packard Development Company, L.P.
InventorsNiranian Damera-Venkata, Utuk A. Agar
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Abstract
An output halftone image is formed from an input image having a plurality of input image pixels. The output image is formed by processing the input image pixels with a halftoning process that incorporates a hard dot stability constraint. The halftoning process forces a determination to produce a dot for each of N output halftone image pixels following an output halftone image pixel dot that would otherwise be isolated, where N≧1.
Claims27
A method for forming an output halftone image having a plurality of output halftone image pixels from an input image having a plurality of input image pixels, the method comprising processing the input image pixels with a halftoning process that incorporates a hard dot stability constraint, the process forcing a determination to produce a dot for each of M output halftone image pixels following an output halftone image pixel dot that would otherwise be isolated, where M≧1.
A method for forming an output halftone image having a plurality of output halftone image pixels from an input image having a plurality of input image pixels, comprising:
- determining whether a dot should be produced for a current output halftone image pixel based upon a pixel value of the current input image pixel, unless that determination has already been made;
- if a determination is made that a dot should be produced for the current output halftone image pixel, then determining whether that dot would be an isolated dot, unless that determination has already been made;
- if a determination is made that an isolated dot would be produced, then making a determination that a dot will be produced at the next M current output halftone image pixel locations, where M is an integer ≧1;
- and
- producing a dot for the current output halftone image pixel if a determination was made that a dot should be produced for that pixel in any of the preceding steps, and otherwise, not producing a dot for the current output halftone image pixel.
An image forming device for forming an output halftone image having a plurality of output halftone image pixels from an input image having a plurality of input image pixels, the device comprising a processor for processing the input image pixels in order to determine whether to produce a dot or not for each of the output halftone image pixels, the processor using a halftoning process that incorporates a hard dot stability constraint and that forces a determination to produce a dot for each of M output halftone image pixels following an output halftone image pixel dot which would otherwise be isolated, where M≧1.
An article for a processor, the article comprising memory encoded with a program for instructing the processor to form an output halftone image having a plurality of output halftone image pixels from an input image having a plurality of input image pixels by processing the input image pixels in order to determine whether to produce a dot for each of the output pixels, the processor using a halftoning process that incorporates a hard dot stability constraint that forces a determination to produce a dot for at least one output pixel following an output pixel dot that would otherwise be isolated.
Dependencies are inferred from the claim text.