US5742405A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and system for forming multi-level halftone images from an input digital image
Assignee: Eastman Kodak Co
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Filing: 1995-01-26
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Granted: 1998-04-21
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Expires: 2015-01-26
Abstract
Abstract A method for forming a multi-level halftone image from an input digital image having a plurality of pixels so that visibility of halftone patterns is minimized; comprises the steps of transforming input pixel values which represent the tone level of each pixel into modified pixel values which are approximately linear with perceived lightness; applying a multi-level halftoning process to the modified pixel values to produce halftone pixel values having a reduced number of tone levels which are uniformly distributed with respect to the modified pixel values; and transforming the halftone pixel values into output pixel values for permitting an output device to display the digital image so that visibility of halftone patterns is minimized.
Inventors
- 👤 Kevin Edward Spaulding
- 👤 Rodney L. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:05
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40087
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
137 words
A method for forming a multi-level halftone image from an input digital image having a plurality of pixels so that visibility of halftone patterns is minimized, comprising the steps of: (a) transforming input pixel values which represent the tone level of each pixel into modified pixel values which are approximately linear with perceived lightness so that the modification of each said modified pixel value is based on input from only a single channel; (b) applying a multi-level half toning process to the modified pixel values to produce halftone pixel values having a reduced number of tone levels which are uniformly distributed with respect to the modified pixel values; and (c) transforming the halftone pixel values into output pixel values for permitting an output device to display the digital image so that visibility of halftone patterns is minimized.
Claim 2
Independent Claim
137 words
A method for forming a multi-level halftone image from an input digital image having a plurality of pixels so that visibility of halftone patterns is minimized, comprising the steps of: (a) transforming input pixel values which represent the tone level of each pixel into modified pixel values which are approximately linear with perceived lightness so that the modification of each said modified pixel value is based on input from only a single channel; (b) applying a multi-level half toning process to the modified pixel values to produce halftone pixel values having a reduced number of tone levels which are uniformly distributed with respect to the modified pixel values; and (c) transforming the halftone pixel values into output pixel values for permitting an output device to display the digital image so that visibility of halftone patterns is minimized.
Claim 3
Dependent Claim
32 words
The method as in claim 1, wherein the transformation of step (a) is implemented using a look-up table which stores the modified pixel value corresponding to each of the input pixel values.
Claim 4
Dependent Claim
17 words
The method as in claim 1, wherein the modified pixel values are linear with CIE L* values.
Claim 5
Dependent Claim
19 words
The method as in claim 1, wherein the multi-level halftoning process in step (b) is a multi-level dither process.
Claim 6
Dependent Claim
20 words
The method as in claim 1, wherein the multi-level halftoning process in step (b) is a multi-level error diffusion process.
Claim 7
Dependent Claim
32 words
The method as in claim 1, wherein the transformation of step (c) is implemented using a look-up table which stores the output pixel value corresponding to each of the halftone pixel values.
Claim 8
Dependent Claim
20 words
The method as in claim 1 further comprising the step of storing the halftone pixel values in a storage device.
Claim 9
Dependent Claim
26 words
The method as in claim 1, wherein steps (a), (b) and (c) are applied to each channel of a digital image having two or more channels.
Claim 10
Dependent Claim
24 words
The method as in claim 1, wherein the halftone pixel values are transmitted across a digital communication channel for displaying on a remote device.
Claim 11
Dependent Claim
13 words
The method as in claim 1, wherein the output device is a printer.
Claim 12
Dependent Claim
20 words
The method as in claim 10, wherein steps (a), (b) and (c) are performed in a processor of the printer.
Claim 13
Independent Claim
139 words
A system for forming a multi-level halftone image from an input digital image having a plurality of pixels so that visibility of halftone patterns is minimized, comprising: (a) means for transforming input pixel values which represent the tone level of each pixel into modified pixel values which are approximately linear with perceived lightness so that the modification of each said modified pixel value is based on input from only a single channel; (b) means for applying a multi-level halftoning process to the modified pixel values to produce halftone pixel values having a reduced number of tone levels which are uniformly distributed with respect to the modified pixel values; and (c) means for transforming the halftone pixel values into output pixel values for permitting an output device to display the digital image so that visibility of halftone patterns is minimized.
Claim 14
Independent Claim
139 words
A system for forming a multi-level halftone image from an input digital image having a plurality of pixels so that visibility of halftone patterns is minimized, comprising: (a) means for transforming input pixel values which represent the tone level of each pixel into modified pixel values which are approximately linear with perceived lightness so that the modification of each said modified pixel value is based on input from only a single channel; (b) means for applying a multi-level halftoning process to the modified pixel values to produce halftone pixel values having a reduced number of tone levels which are uniformly distributed with respect to the modified pixel values; and (c) means for transforming the halftone pixel values into output pixel values for permitting an output device to display the digital image so that visibility of halftone patterns is minimized.
Claim 15
Dependent Claim
36 words
The system as in claim 12, wherein said means for transforming input pixel values into modified pixel values is a look-up table which stores the modified pixel value corresponding to each of the input pixel values.
Claim 16
Dependent Claim
36 words
The system as in claim 13, wherein said means for transforming the halftone pixel values into output pixel values is a look-up table which stores the output pixel value corresponding to each of the halftone values.
Claim 17
Dependent Claim
22 words
The system as in claim 12 wherein said means for applying a multi-level halftoning process further includes applying a multi-level dither process.
Claim 18
Dependent Claim
23 words
The system as in claim 12 wherein said means for applying a multi-level halftoning process further includes applying a multi-level error diffusion process.
Claim 19
Independent Claim
163 words
A method for forming a multi-level halftone image from an input image having a plurality of pixels so that the visibility of halftone patterns is minimized, comprising the steps of: (a) transforming input pixel values which represent a tone level of each pixel using a look-up table to form modified pixel values which are approximately linear with perceived lightless so that the modification of each said modified pixel value is based on input from only a single channel; (b) applying a multi-level halftoning process to the modified pixel values for each color channel to produce halftone pixel values having a reduced number of tone levels which are uniformly distributed; (c) storing the halftone pixel values in a digital memory; and (d) retrieving the halftone pixels from the digital memory and transforming the halftone pixel values using a look-up table to form output pixel values for permitting an output device to display the digital image so that the visibility of halftone patterns is minimized.
Claim 20
Independent Claim
163 words
A method for forming a multi-level halftone image from an input image having a plurality of pixels so that the visibility of halftone patterns is minimized, comprising the steps of: (a) transforming input pixel values which represent a tone level of each pixel using a look-up table to form modified pixel values which are approximately linear with perceived lightless so that the modification of each said modified pixel value is based on input from only a single channel; (b) applying a multi-level halftoning process to the modified pixel values for each color channel to produce halftone pixel values having a reduced number of tone levels which are uniformly distributed; (c) storing the halftone pixel values in a digital memory; and (d) retrieving the halftone pixels from the digital memory and transforming the halftone pixel values using a look-up table to form output pixel values for permitting an output device to display the digital image so that the visibility of halftone patterns is minimized.
Claim 21
Independent Claim
154 words
A method for forming a color multi-level halftone image from a color input image having more than one color channel having a plurality of pixels so that the visibility of halftone patterns is minimized, comprising the steps of: (a) transforming input pixel values which represent the tone level of each pixel for each color channel into modified pixel values which are approximately linear with perceived lightness for colors which are neutral so that the modification of each said modified pixel value is based on input from only a single channel; (b) applying a multi-level halftoning process to the modified pixel values for each color channel to produce halftone pixel values having a reduced number of tone levels which are uniformly distributed; and (c) transforming the halftone pixel values for each color channel into output pixel values for permitting an output device to display the digital image so that visibility of halftone patterns is minimized.
Claim 22
Independent Claim
154 words
A method for forming a color multi-level halftone image from a color input image having more than one color channel having a plurality of pixels so that the visibility of halftone patterns is minimized, comprising the steps of: (a) transforming input pixel values which represent the tone level of each pixel for each color channel into modified pixel values which are approximately linear with perceived lightness for colors which are neutral so that the modification of each said modified pixel value is based on input from only a single channel; (b) applying a multi-level halftoning process to the modified pixel values for each color channel to produce halftone pixel values having a reduced number of tone levels which are uniformly distributed; and (c) transforming the halftone pixel values for each color channel into output pixel values for permitting an output device to display the digital image so that visibility of halftone patterns is minimized.
Claim 23
Dependent Claim
32 words
The method as in claim 18, wherein the transformation of step (a) is implemented using a look-up table which stores the modified pixel value corresponding to each of the input pixel values.
Claim 24
Dependent Claim
17 words
The method as in claim 18, wherein the modified pixel values are linear with CIE L* values.
Claim 25
Dependent Claim
19 words
The method as in claim 18, wherein the multi-level halftoning process in step (b) is a multi-level dither process.
Claim 26
Dependent Claim
20 words
The method as in claim 18, wherein the multi-level halftoning process in step (b) is a multi-level error diffusion process.
Claim 27
Dependent Claim
24 words
The method as in claim 18, wherein the halftone pixel values are transmitted across a digital communication channel for displaying on a remote device.
Claim 28
Dependent Claim
13 words
The method as in claim 18, wherein the output device is a printer.
Claim 29
Dependent Claim
20 words
The method as in claim 24, wherein steps (a), (b) and (c) are performed in a processor of the printer.
Claim 30
Dependent Claim
14 words
The method as in claim 18, wherein the output device is a video display.
Claim 31
Dependent Claim
32 words
The method as in claim 18, wherein the transformation of step (c) is implemented using a look-up table which stores the output pixel value corresponding to each of the halftone pixel values.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-04-20 | 2001-10-20 | 2002-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-04-20 | 2005-10-20 | 2006-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-04-20 | 2009-10-20 | 2010-04-21 | $7700.00 | Window Closed / Lapsed |