Digital halftoning
AssigneePolaroid Corporation
InventorsDaniel P. Bybell, Jay E. Thornton, Dana F. Schuh
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Abstract
In one aspect of the present invention, a method is provided for producing a halftone of a source image. The halftone includes halftone pixels. The halftone pixels are suitable for containing halftone dots. The method selects glyphs corresponding to intensities of regions (e.g., pixels) in the source image. The glyphs contain one or more halftone dots. The method locates halftone dots within the halftone pixels such that for at least one pair of halftone dots contained within a pair of halftone pixels sharing a common boundary, the halftone dots in the pair of halftone pixels extend in opposite directions from the common boundary.
Claims20
A method for generating a halftone of a source image, the halftone including halftone pixels, the halftone pixels being suitable for containing halftone dots, the method comprising steps of:
- (A) selecting glyphs corresponding to regions in the source image, the glyphs including halftone dots;
- (B) selecting, from among the halftone pixels, a first halftone pixel and a second halftone pixel that share a pixel boundary;
- (C) locating a first one of the halftone dots within the first halftone pixel so that the first halftone dot abuts the pixel boundary;
- and
- (D) locating a second one of the halftone dots within the second halftone pixel so that the second halftone dot abuts the pixel boundary.
A method for generating a halftone of a digital source image including a two-dimensional array of source image pixels, the halftone including halftone pixels, the halftone pixels being suitable for containing halftone dots, the method comprising steps of:
- (A) selecting halftone dots corresponding to source image pixels, the size of each of the halftone dots being inversely related to the intensity of one of the source image pixels;
- (B) selecting, from among the halftone pixels, a first halftone pixel and a second halftone pixel that share a pixel boundary that is perpendicular to a slow scan direction of an output device on which the halftone may be rendered;
- (C) locating a first one of the halftone dots within the first halftone pixel so that the first halftone dot abuts the pixel boundary;
- (D) locating a second one of the halftone dots within the second halftone pixel so that the second halftone dot abuts the pixel boundary;
- and
- (E) rendering the halftone on an output medium using a thermal printer, wherein the step of rendering includes a step of rendering the first and second halftone dots as a single contiguous mark.
A method for generating a halftone of a digital source image including a two-dimensional array of source image pixels, the halftone including halftone pixels, the halftone pixels being suitable for containing halftone dots, the method comprising steps of:
- (A) identifying intensities of the source image pixels;
- (B) selecting glyphs corresponding to the identified intensities, the glyphs including halftone dots;
- (C) selecting halftone dots from the glyphs based on the coordinates of the source image pixels;
- (D) selecting, from among the halftone pixels, a first halftone pixel and a second halftone pixel that share a pixel boundary that is perpendicular to a slow scan direction of an output device on which the halftone may be rendered;
- (E) locating a first one of the halftone dots within the first halftone pixel so that the first halftone dot abuts the pixel boundary;
- (F) locating a second one of the halftone dots within the second halftone pixel so that the second halftone dot abuts the pixel boundary;
- and
- (G) rendering the halftone on an output medium using a thermal printer, wherein the step of rendering includes a step of rendering the first and second halftone dots as a single contiguous mark.
Dependencies are inferred from the claim text.