US5768411A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dispersed-dot dither with improved light-color smoothness
Assignee: Seiko Epson Corp
•
Filing: 1996-02-26
•
Granted: 1998-06-16
•
Expires: 2016-02-26
Abstract
Abstract To convert the multiple-bit-resolution intensity information for a color component of a given pixel into the ink-on or ink-off command required to control a printer, the source values for different pixels are compared with thresholds in a "dither matrix" of different thresholds for different pixels, and a given pixel is printed if the source value exceeds the dither-matrix value for that pixel. Different dither matrices are employed for different color components, with the result that lighter-color areas have a smoother appearance than they would result if a common dither matrix were employed for all color components.
Inventors
- 👤 Joseph Shu
- 👤 Chia-Hsin Li
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:59
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/52
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
231 words
For operating an image-presenting mechanism to present an image, a method comprising the steps of: in response to electrical source-image signals representing a source image, performing a sequence of at least one image-revision step, in which sequence each image-revision step receives an input image consisting of input pixels and produces therefrom an output image consisting of output pixels, wherein the input image of the first image-revision step is the source image and the input image of any subsequent image-revision step is the output image of the preceding image-revision step, wherein one said image-revision step is a half-toning step whose input image consists of source color pixel values of a first resolution each of which consists of a plurality of color component values and whose output image consists of output pixel values of a second resolution, coarser than the first resolution, that the half-toning step determines by applying respective dither matrices to respective components of the source image, wherein a first dither matrix applied to at least one of the source-image components differs from a second dither matrix applied to at least one of the other source-image components such that the elements of the first dither matrix are the differences between a common range value and the corresponding elements of the second dither matrix; and applying to the image-presenting mechanism electrical command signals that represent the output of the last image-revision step.
Claim 2
Dependent Claim
231 words
For operating an image-presenting mechanism to present an image, a method comprising the steps of: in response to electrical source-image signals representing a source image, performing a sequence of at least one image-revision step, in which sequence each image-revision step receives an input image consisting of input pixels and produces therefrom an output image consisting of output pixels, wherein the input image of the first image-revision step is the source image and the input image of any subsequent image-revision step is the output image of the preceding image-revision step, wherein one said image-revision step is a half-toning step whose input image consists of source color pixel values of a first resolution each of which consists of a plurality of color component values and whose output image consists of output pixel values of a second resolution, coarser than the first resolution, that the half-toning step determines by applying respective dither matrices to respective components of the source image, wherein a first dither matrix applied to at least one of the source-image components differs from a second dither matrix applied to at least one of the other source-image components such that the elements of the first dither matrix are the differences between a common range value and the corresponding elements of the second dither matrix; and applying to the image-presenting mechanism electrical command signals that represent the output of the last image-revision step.
Claim 3
Dependent Claim
30 words
A method as defined in claim 1 wherein at least one of the dither matrices applied to a component of the half-toning step's input image is a dispersed-dot dither matrix.
Claim 4
Dependent Claim
51 words
A method as defined in claim 1 wherein the component of the half-toning step's input image to which the first dither matrix is applied is a cyan image component and the component of the half-toning step's input image to which the second dither matrix is applied is a magenta image component.
Claim 5
Dependent Claim
51 words
A method as defined in claim 2 wherein the component of the half-toning step's input image to which the first dither matrix is applied is a cyan image component and the component of the half-toning step's input image to which the second dither matrix is applied is a magenta image component.
Claim 6
Dependent Claim
238 words
For operating an image-presenting mechanism to present an image, an apparatus comprising: image-revision circuitry responsive to electrical source-image signals representing the source image for performing a sequence of at least one image-revision step, in which sequence each image-revision step receives an input image consisting of input pixels and produces therefrom an output image consisting of output pixels, wherein the input image of the first image-revision step is the source image and the input image of any subsequent image-revision step is the output image of the preceding image-revision step, wherein one said image-revision step is a half-toning step whose input image consists of source color pixel values of a first resolution each of which consists of a plurality of color component values and whose output image consists of output pixel values of a second resolution, coarser than the first resolution, that the half-toning step determines by applying respective dither matrices to respective components of the source image, wherein a first dither matrix applied to at least one of the source-image components differs from a second dither matrix applied to at least one of the other source-image components such that the elements of the first dither matrix are the differences between a common range value and the corresponding elements of the second dither matrix; and output circuitry responsive to the image-revision circuitry for applying to the image-presenting mechanism electrical command signals that represent the output of the last image-revision step.
Claim 7
Dependent Claim
238 words
For operating an image-presenting mechanism to present an image, an apparatus comprising: image-revision circuitry responsive to electrical source-image signals representing the source image for performing a sequence of at least one image-revision step, in which sequence each image-revision step receives an input image consisting of input pixels and produces therefrom an output image consisting of output pixels, wherein the input image of the first image-revision step is the source image and the input image of any subsequent image-revision step is the output image of the preceding image-revision step, wherein one said image-revision step is a half-toning step whose input image consists of source color pixel values of a first resolution each of which consists of a plurality of color component values and whose output image consists of output pixel values of a second resolution, coarser than the first resolution, that the half-toning step determines by applying respective dither matrices to respective components of the source image, wherein a first dither matrix applied to at least one of the source-image components differs from a second dither matrix applied to at least one of the other source-image components such that the elements of the first dither matrix are the differences between a common range value and the corresponding elements of the second dither matrix; and output circuitry responsive to the image-revision circuitry for applying to the image-presenting mechanism electrical command signals that represent the output of the last image-revision step.
Claim 8
Dependent Claim
30 words
An apparatus as defined in claim 5 wherein at least one of the dither matrices applied to a component of the half-toning step's input image is a dispersed-dot dither matrix.
Claim 9
Dependent Claim
51 words
An apparatus as defined in claim 5 wherein the component of the half-toning step's input image to which the first dither matrix is applied is a cyan image component and the component of the half-toning step's input image to which the second dither matrix is applied is a magenta image component.
Claim 10
Dependent Claim
51 words
An apparatus as defined in claim 6 wherein the component of the half-toning step's input image to which the first dither matrix is applied is a cyan image component and the component of the half-toning step's input image to which the second dither matrix is applied is a magenta image component.
Claim 11
Dependent Claim
237 words
An imaging apparatus comprising: an image-presenting mechanism for presenting an image; image-revision circuitry responsive to electrical source-image signals representing a source image for performing a sequence of at least one image-revision step, in which sequence each image-revision step receives an input image consisting of input pixels and produces therefrom an output image consisting of output pixels, wherein the input image of the first image-revision step is the source image and the input image of any subsequent image-revision step is the output image of the preceding image-revision step, wherein one said image-revision step is a half-toning step whose input image consists of source color pixel values of a first resolution each of which consists of a plurality of color component values and whose output image consists of output pixel values of a second resolution, coarser than the first resolution, that the half-toning step determines by applying respective dither matrices to respective components of the source image, wherein a first dither matrix applied to at least one of the source-image components differs from a second dither matrix applied to at least one of the other source-image components such that the elements of the first dither matrix are the differences between a common range value and the corresponding elements of the second dither matrix; and output circuitry responsive to the image-revision circuitry for applying to the image-presenting mechanism electrical command signals that represent the output of the last image-revision step.
Claim 12
Dependent Claim
237 words
An imaging apparatus comprising: an image-presenting mechanism for presenting an image; image-revision circuitry responsive to electrical source-image signals representing a source image for performing a sequence of at least one image-revision step, in which sequence each image-revision step receives an input image consisting of input pixels and produces therefrom an output image consisting of output pixels, wherein the input image of the first image-revision step is the source image and the input image of any subsequent image-revision step is the output image of the preceding image-revision step, wherein one said image-revision step is a half-toning step whose input image consists of source color pixel values of a first resolution each of which consists of a plurality of color component values and whose output image consists of output pixel values of a second resolution, coarser than the first resolution, that the half-toning step determines by applying respective dither matrices to respective components of the source image, wherein a first dither matrix applied to at least one of the source-image components differs from a second dither matrix applied to at least one of the other source-image components such that the elements of the first dither matrix are the differences between a common range value and the corresponding elements of the second dither matrix; and output circuitry responsive to the image-revision circuitry for applying to the image-presenting mechanism electrical command signals that represent the output of the last image-revision step.
Claim 13
Dependent Claim
31 words
An imaging apparatus as defined in claim 9 wherein at least one of the dither matrices applied to a component of the half-toning step's input image is a dispersed-dot dither matrix.
Claim 14
Dependent Claim
52 words
An imaging apparatus as defined in claim 9 wherein the component of the half-toning step's input image to which the first dither matrix is applied is a cyan image component and the component of the half-toning step's input image to which the second dither matrix is applied is a magenta image component.
Claim 15
Dependent Claim
52 words
An imaging apparatus as defined in claim 10 wherein the component of the half-toning step's input image to which the first dither matrix is applied is a cyan image component and the component of the half-toning step's input image to which the second dither matrix is applied is a magenta image component.
Claim 16
Dependent Claim
256 words
A storage medium containing instructions readable by a computer to configure the computer to function as an apparatus for operating an image-presenting mechanism to present an image, which apparatus comprises: image-revision circuitry responsive to electrical source-image signals representing a source image for performing a sequence of at least one image-revision step, in which sequence each image-revision step receives an input image consisting of input pixels and produces therefrom an output image consisting of output pixels, wherein the input image of the first image-revision step is the source image and the input image of any subsequent image-revision step is the output image of the preceding image-revision step, wherein one said image-revision step is a half-toning step whose input image consists of source color pixel values of a first resolution each of which consists of a plurality of color component values and whose output image consists of output pixel values of a second resolution, coarser than the first resolution, that the half-toning step determines by applying respective dither matrices to respective components of the source image, wherein a first dither matrix applied to at least one of the source-image components differs from a second dither matrix applied to at least one of the other source-image components such that the elements of the first dither matrix are the differences between a common range value and the corresponding elements of the second dither matrix; and output circuitry responsive to the image-revision circuitry for applying to the image-presenting mechanism electrical command signals that represent the output of the last image-revision step.
Claim 17
Dependent Claim
256 words
A storage medium containing instructions readable by a computer to configure the computer to function as an apparatus for operating an image-presenting mechanism to present an image, which apparatus comprises: image-revision circuitry responsive to electrical source-image signals representing a source image for performing a sequence of at least one image-revision step, in which sequence each image-revision step receives an input image consisting of input pixels and produces therefrom an output image consisting of output pixels, wherein the input image of the first image-revision step is the source image and the input image of any subsequent image-revision step is the output image of the preceding image-revision step, wherein one said image-revision step is a half-toning step whose input image consists of source color pixel values of a first resolution each of which consists of a plurality of color component values and whose output image consists of output pixel values of a second resolution, coarser than the first resolution, that the half-toning step determines by applying respective dither matrices to respective components of the source image, wherein a first dither matrix applied to at least one of the source-image components differs from a second dither matrix applied to at least one of the other source-image components such that the elements of the first dither matrix are the differences between a common range value and the corresponding elements of the second dither matrix; and output circuitry responsive to the image-revision circuitry for applying to the image-presenting mechanism electrical command signals that represent the output of the last image-revision step.
Claim 18
Dependent Claim
31 words
A storage medium as defined in claim 13 wherein at least one of the dither matrices applied to a component of the half-toning step's input image is a dispersed-dot dither matrix.
Claim 19
Dependent Claim
52 words
A storage medium as defined in claim 13 wherein the component of the half-toning step's input image to which the first dither matrix is applied is a cyan image component and the component of the half-toning step's input image to which the second dither matrix is applied is a magenta image component.
Claim 20
Dependent Claim
52 words
A storage medium as defined in claim 14 wherein the component of the half-toning step's input image to which the first dither matrix is applied is a cyan image component and the component of the half-toning step's input image to which the second dither matrix is applied is a magenta image component.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-06-15 | 2001-12-15 | 2002-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-06-15 | 2005-12-15 | 2006-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-06-15 | 2009-12-15 | 2010-06-16 | $7700.00 | Window Closed / Lapsed |