US7859723B2
Active / In Force
US
⏱️ 2.5 years remaining
Image processing to perform error diffusion with dots formed based color component values and their sum relative to a threshold
Assignee: Canon Inc
•
Filing: 2009-04-28
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Granted: 2010-12-28
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Expires: 2029-04-28
Abstract
Abstract Image processing apparatus and image processing method for formation of high quality image by high-speed error diffusion processing by execution of more complicated threshold condition processing in a simple manner. When error diffusion processing is performed on multivalued image data having plural density components and the result of processing is outputted, upon execution of error diffusion processing on a first density component among the plural density components, a threshold value used in the error diffusion processing is determined based on a density value of a second density component, then the error diffusion processing is performed on the first density component based on the determined threshold value, and the result of execution of the error diffusion processing is outputted. Further, upon execution of the error diffusion processing on the second density component among the plural density components, a threshold value used in the error diffusion processing is determined based on a density value of the first density component, then the error diffusion processing is performed on the second density component based on the determined threshold value, and the result of the error diffusion processing is outputted.
Inventors
- 👤 Akitoshi Yamada
- 👤 Hiromitsu Hirabayashi
- 👤 Masao Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:33
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/52
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
331 words
An image processing apparatus for performing error diffusion processing on multi-valued image data comprised of plural color components including a first color component and a second color component, comprising: a generation unit configured to generate values of the first and second color components for a pixel of interest from multi-valued image data of the first and second color components representing the pixel of interest and multi-valued image data of the first and second color components error-diffused to the pixel of interest; a binarization unit configured to binarize the values of the first and second color components for the pixel of interest generated by said generation unit; and an image formation unit configured to form an image based on a result of the binarization, wherein said binarization unit binarizes the values of the first and second color components: (1) in a case where a sum of the values of the first and second color components is less than a predetermined threshold value, such that neither a dot of the first color component nor a dot of the second color component is formed by said image formation unit; (2) in a case where the sum of the values of the first and second color components is greater than the predetermined threshold value and one of the values of the first and second color components is equal to or less than the predetermined threshold value, such that only a dot of one of the first and second color components having a greater value than that of the other of the first and second color components is formed by said image formation unit; and (3) in a case where the sum of the values of the first and second color components is greater than the predetermined threshold value and both of the values of the first and second color components are greater than the predetermined threshold value, such that both dots of the first and second color components are formed by said image formation unit.
Claim 2
Dependent Claim
331 words
An image processing apparatus for performing error diffusion processing on multi-valued image data comprised of plural color components including a first color component and a second color component, comprising: a generation unit configured to generate values of the first and second color components for a pixel of interest from multi-valued image data of the first and second color components representing the pixel of interest and multi-valued image data of the first and second color components error-diffused to the pixel of interest; a binarization unit configured to binarize the values of the first and second color components for the pixel of interest generated by said generation unit; and an image formation unit configured to form an image based on a result of the binarization, wherein said binarization unit binarizes the values of the first and second color components: (1) in a case where a sum of the values of the first and second color components is less than a predetermined threshold value, such that neither a dot of the first color component nor a dot of the second color component is formed by said image formation unit; (2) in a case where the sum of the values of the first and second color components is greater than the predetermined threshold value and one of the values of the first and second color components is equal to or less than the predetermined threshold value, such that only a dot of one of the first and second color components having a greater value than that of the other of the first and second color components is formed by said image formation unit; and (3) in a case where the sum of the values of the first and second color components is greater than the predetermined threshold value and both of the values of the first and second color components are greater than the predetermined threshold value, such that both dots of the first and second color components are formed by said image formation unit.
Claim 3
Dependent Claim
107 words
The apparatus according to claim 1 , wherein said binarization unit includes: a first comparison unit configured to compare the sum of the values of the first and second color components with the predetermined threshold value; a second comparison unit configured to compare the value of the first color component with that of the second color component so as to discriminate which one is greater than the other; a third comparison unit configured to compare the value of the first color component with the predetermined threshold value; and a fourth comparison unit configured to compare the value of the second color component with the predetermined threshold value.
Claim 4
Dependent Claim
44 words
The apparatus according to claim 1 , wherein the plural color components are a yellow component, a magenta component, a cyan component and a black component, and the first color component is the cyan component, and the second color component is the magenta component.
Claim 5
Dependent Claim
16 words
The apparatus according to claim 1 , wherein said image formation unit is an ink-jet printer.
Claim 6
Dependent Claim
23 words
The apparatus according to claim 1 , wherein the predetermined threshold value is approximately half of a maximum value of each color component.
Claim 7
Dependent Claim
326 words
An image processing method for performing error diffusion processing on multi-valued image data comprised of plural color components including a first color component and a second color component and outputting a result of the image processing to an image formation apparatus, comprising: a generation step of generating values of the first and second color components for a pixel of interest from multi-valued image data of the first and second color components representing the pixel of interest and multi-valued image data of the first and second color components error-diffused to the pixel of interest; and a binarization step of binarizing the values of the first and second color components for the pixel of interest generated at said generation step, wherein said binarization step binarizes the values of the first and second color components: (1) in a case where a sum of the values of the first and second color components is less than a predetermined threshold value, such that neither a dot of the first color component nor a dot of the second color component is formed by said image formation apparatus; (2) in a case where the sum of the values of the first and second color components is greater than the predetermined threshold value and one of the values of the first and second color components is equal to or less than the predetermined threshold value, such that only a dot of one of the first and second color components having a greater value than that of the other of the first and second color components is formed by said image formation apparatus; and (3) in a case where the sum of the values of the first and second color components is greater than the predetermined threshold value and both of the values of the first and second color components are greater than the predetermined threshold value, such that both dots of the first and second color components are formed by said image formation apparatus.
Claim 8
Dependent Claim
326 words
An image processing method for performing error diffusion processing on multi-valued image data comprised of plural color components including a first color component and a second color component and outputting a result of the image processing to an image formation apparatus, comprising: a generation step of generating values of the first and second color components for a pixel of interest from multi-valued image data of the first and second color components representing the pixel of interest and multi-valued image data of the first and second color components error-diffused to the pixel of interest; and a binarization step of binarizing the values of the first and second color components for the pixel of interest generated at said generation step, wherein said binarization step binarizes the values of the first and second color components: (1) in a case where a sum of the values of the first and second color components is less than a predetermined threshold value, such that neither a dot of the first color component nor a dot of the second color component is formed by said image formation apparatus; (2) in a case where the sum of the values of the first and second color components is greater than the predetermined threshold value and one of the values of the first and second color components is equal to or less than the predetermined threshold value, such that only a dot of one of the first and second color components having a greater value than that of the other of the first and second color components is formed by said image formation apparatus; and (3) in a case where the sum of the values of the first and second color components is greater than the predetermined threshold value and both of the values of the first and second color components are greater than the predetermined threshold value, such that both dots of the first and second color components are formed by said image formation apparatus.
Claim 9
Dependent Claim
347 words
A computer readable memory medium on which is stored a computer executable a program that, when executed by a computer performs an image processing method for performing error diffusion processing on multi-valued image data comprised of plural color components including a first color component and a second color component and outputting a result of the image processing to an image formation apparatus, comprising: a generation step of generating values of the first and second color components for a pixel of interest from multi-valued image data of the first and second color components representing the pixel of interest and multi-valued image data of the first and second color components error-diffused to the pixel of interest; and a binarization step of binarizing the values of the first and second color components for the pixel of interest generated at said generation step, wherein said binarization step binarizes the values of the first and second color components: (1) in a case where a sum of the values of the first and second color components is less than a predetermined threshold value, such that neither a dot of the first color component nor a dot of the second color component is formed by said image formation apparatus; (2) in a case where the sum of the values of the first and second color components is greater than the predetermined threshold value and one of the values of the first and second color components is equal to or less than the predetermined threshold value, such that only a dot of one of the first and second color components having a greater value than that of the other of the first and second color components is formed by said image formation apparatus; and (3) in a case where the sum of the values of the first and second color components is greater than the predetermined threshold value and both of the values of the first and second color components are greater than the predetermined threshold value, such that both dots of the first and second color components are formed by said image formation apparatus.
Claim 10
Dependent Claim
347 words
A computer readable memory medium on which is stored a computer executable a program that, when executed by a computer performs an image processing method for performing error diffusion processing on multi-valued image data comprised of plural color components including a first color component and a second color component and outputting a result of the image processing to an image formation apparatus, comprising: a generation step of generating values of the first and second color components for a pixel of interest from multi-valued image data of the first and second color components representing the pixel of interest and multi-valued image data of the first and second color components error-diffused to the pixel of interest; and a binarization step of binarizing the values of the first and second color components for the pixel of interest generated at said generation step, wherein said binarization step binarizes the values of the first and second color components: (1) in a case where a sum of the values of the first and second color components is less than a predetermined threshold value, such that neither a dot of the first color component nor a dot of the second color component is formed by said image formation apparatus; (2) in a case where the sum of the values of the first and second color components is greater than the predetermined threshold value and one of the values of the first and second color components is equal to or less than the predetermined threshold value, such that only a dot of one of the first and second color components having a greater value than that of the other of the first and second color components is formed by said image formation apparatus; and (3) in a case where the sum of the values of the first and second color components is greater than the predetermined threshold value and both of the values of the first and second color components are greater than the predetermined threshold value, such that both dots of the first and second color components are formed by said image formation apparatus.
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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) | 2013-12-27 | 2014-06-28 | 2014-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2017-12-27 | 2018-06-28 | 2018-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2021-12-27 | 2022-06-28 | 2022-12-28 | $7700.00 | Window Closed / Lapsed |