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US 8,134,749 B2Granted
Multi-bit-depth error diffusion for the reproduction of color or monochrome images
AssigneeSharp Laboratories of America, Inc.
InventorChing-Wei Chang
Life of this patent
Estimating the term…
Abstract
An image processing system including a lookup table having multi-bit printer output levels and an imaging input level. The imaging input level may be associated with a range of input pixel densities. The system further includes a processor configured to compare the imaging input level with one or more preconfigured threshold output values associated with the printer output levels. The imaging input level may be preferentially weighted to select a printer output level having an increased bit depth.
Claims24
A non-transitory computer-readable medium having stored thereon computer-executable instructions that, in response to execution by a computing system, cause the computing system to perform operations comprising:
- determining an image input level;
- associating the image input level with one or more threshold output values which identify a plurality of printer output levels including a first printer output level;
- adjusting the image input level by error diffusion;
- comparing the adjusted image input level with the one or more threshold output values;
- and
- selecting a printer output level in response to comparing the adjusted image input level with the one or more threshold output values, wherein the first printer output level is selected for a first print area when the adjusted input level is greater than the one or more threshold output values, wherein a second printer output level is selected for a second print area when the adjusted image input level is less than the one or more threshold output values, and wherein the first and second printer output levels are selected for a transition area interposed between the first and second print areas.
3 more elements
A method, comprising:
- determining an image input level;
- associating the image input level with one or more threshold output values which identify a plurality of printer output levels including a first printer output level;
- adjusting, with a processing device, the image input level by error diffusion;
- comparing the adjusted image input level with the one or more threshold output values;
- selecting a printer output level in response to comparing the adjusted image input level with the one or more threshold output values, wherein the first printer output level is selected when the adjusted input level is greater than the one or more threshold output values, and wherein a second printer output level is selected when the adjusted image input level is less than the one or more threshold output values;
- and,
- taking an average value of two or more of the threshold output values, wherein the printer output level is selected as the average value.
4 more elements
An apparatus, comprising:
- means for determining an image input level;
- means for associating the image input level with one or more threshold output values which identify a plurality of printer output levels including a first printer output level;
- means for adjusting the image input level by error diffusion;
- means for comparing the adjusted image input level with the one or more threshold output values;
- and
- means for selecting a printer output level in response to comparing the adjusted image input level with the one or more threshold output values, wherein the first printer output level is selected when the adjusted input level is greater than the one or more threshold output values, wherein a second printer output level is selected when the adjusted image input level is less than the one or more threshold output values, and wherein the printer output level is selected for a print area associated with a substantially uniform grey level to minimize a number of pixels printed in the print area.
3 more elements
A method, comprising:
- determining an image input level;
- associating the image input level with one or more threshold output values which identify a plurality of printer output levels including a first printer output level;
- adjusting the image input level by error diffusion;
- comparing the adjusted image input level with the one or more threshold output values;
- and
- selecting a printer output level from the plurality of printer output levels in response to comparing the adjusted image input level with the one or more threshold output values, wherein the first printer output level is selected when the adjusted input level is greater than the one or more threshold output values, wherein a second printer output level is selected when the adjusted image input level is less than the one or more threshold output values, and wherein at least one of the plurality of printer output levels other than zero is not associated with any threshold output value.
3 more elements
Dependencies are inferred from the claim text.