Serpentine direction reversal in bidirectional error diffusion halftoning
AssigneeHewlett-Packard Development Company, L.P.
InventorsBradley D Chung, Hsue-Yang Liu, Matthew A Shepherd, Mark H Mackenzie, Jason M Quintana
Life of this patent
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Abstract
Bidirectional error diffusion halftoning of data. Pixels are halftoned in one serpentine direction, and pixels are halftoned in an opposite serpentine direction.
Claims15
A printer, comprising:
- a printbar having at least two dice, each die having parallel odd and even rows of staggered print nozzles, the plural dice partially overlapping in the direction of the rows;
- and
- a bidirectional error diffusion halftoner structured to generate halftoned data mappable into firing data for the print nozzles and having a serpentine direction reverser structured to
- halftone image pixels in a first serpentine direction to form the halftoned data until a criterion is met, and
- halftone image pixels in an opposite serpentine direction to form the halftoned data after the criterion is met.
A method for halftoning print data pixels of a page in a row-and-column format for printing, comprising:
- performing bidirectional error diffusion halftoning, in a first serpentine direction, on the pixels until a criterion is met;
- and
- performing the bidirectional error diffusion halftoning, in an opposite serpentine direction, on the pixels after the criterion is met.
A non-transitory computer-readable storage medium having an executable program stored thereon for generating firing data for print nozzles of a printbar of a page-wide printer using bidirectional error diffusion halftoning, wherein the program instructs a processor to:
- for each die in the printbar, determine whether to swap the firing data for odd and even rows of the print nozzles of the die in order to align the die in the printbar;
- first halftone, in a standard serpentine direction, print data pixels corresponding to a die to which the nozzle firing data is not swapped;
- second halftone, in an opposite serpentine direction, print data pixels corresponding to a die to which the nozzle firing data is swapped;
- and
- map halftoned data produced by the first and second halftoning into the firing data.
The medium of claim 15, wherein each pixel comprises contone image data specific to a set of colorants of the page-wide printer.
Dependencies are inferred from the claim text.