US9088753B2
Active / In Force
US
⏱️ 7.2 years remaining
Image forming apparatus, luminance correction method, and storage medium storing program
Assignee: Canon Inc
•
Filing: 2014-01-07
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Granted: 2015-07-21
•
Expires: 2034-01-07
Abstract
Abstract An image processing apparatus includes an image data acquisition unit to acquire image data by optically reading a document. A frequency distribution acquisition unit acquires a first frequency distribution of luminances from the image data acquired by the image data acquisition unit. A generation unit generates a second frequency distribution of luminances of a background of the document, by using a maximum frequency of the first frequency distribution as a maximum frequency of the second frequency distribution of luminances of the background of the document. An acquisition unit acquires information indicating a degree of deviation of the second frequency distribution from the first frequency distribution. A correction unit corrects the second frequency distribution based on the information indicating the degree of deviation acquired by the acquisition unit.
Inventors
- 👤 Hiromitsu Akiba
- 👤 Tetsuya Suwa
- 👤 Nobutaka Miyake
- 👤 Ryosuke Iguchi
- 👤 Yusuke Hashii
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:39
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/6027; H04N1/40; H04N1/407; H04N1/4072; H04N1/4074
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
160 words
An image processing apparatus comprising: an image data acquisition unit configured to acquire image data by optically reading a document; a frequency distribution acquisition unit configured to acquire a first frequency distribution of luminances from the image data acquired by the image data acquisition unit; a generation unit configured to generate a second frequency distribution of luminances of a background of the document, by using a maximum frequency of the first frequency distribution acquired by the frequency distribution acquisition unit as a maximum frequency of the second frequency distribution of luminances of the background of the document; an acquisition unit configured to acquire information indicating a degree of deviation of the second frequency distribution from the first frequency distribution; a correction unit configured to correct the second frequency distribution based on the information indicating the degree of deviation acquired by the acquisition unit; and an image processing unit configured to process the image data using the corrected second frequency distribution.
Claim 2
Dependent Claim
160 words
An image processing apparatus comprising: an image data acquisition unit configured to acquire image data by optically reading a document; a frequency distribution acquisition unit configured to acquire a first frequency distribution of luminances from the image data acquired by the image data acquisition unit; a generation unit configured to generate a second frequency distribution of luminances of a background of the document, by using a maximum frequency of the first frequency distribution acquired by the frequency distribution acquisition unit as a maximum frequency of the second frequency distribution of luminances of the background of the document; an acquisition unit configured to acquire information indicating a degree of deviation of the second frequency distribution from the first frequency distribution; a correction unit configured to correct the second frequency distribution based on the information indicating the degree of deviation acquired by the acquisition unit; and an image processing unit configured to process the image data using the corrected second frequency distribution.
Claim 3
Dependent Claim
32 words
The image processing apparatus according to claim 1 , wherein the correction unit performs the correction by moving a minimum luminance point on the second frequency distribution toward a higher luminance side.
Claim 4
Dependent Claim
39 words
The image processing apparatus according to claim 1 , wherein, in a case when the degree of deviation indicated by the information acquired by the acquisition unit is larger, a degree of correction by the correction unit is larger.
Claim 5
Dependent Claim
30 words
The image processing apparatus according to claim 1 , wherein the second frequency distribution includes a maximum luminance of the first frequency distribution acquired by the frequency distribution acquisition unit.
Claim 6
Dependent Claim
55 words
The image processing apparatus according to claim 1 , wherein the generation unit generates the second frequency distribution, based on a luminance corresponding to the maximum frequency of the first frequency distribution acquired by the frequency distribution acquisition unit and a maximum luminance of the first frequency distribution acquired by the frequency distribution acquisition unit.
Claim 7
Dependent Claim
41 words
The image processing apparatus according to claim 5 , wherein the second frequency distribution generated by the generation unit is symmetrical with respect to the luminance corresponding to the maximum frequency, toward a lower luminance side and a higher luminance side.
Claim 8
Dependent Claim
57 words
The image processing apparatus according to claim 1 , wherein the acquisition unit calculates the degree of deviation by accumulating a frequency difference for each luminance, and, in the accumulation, a weight for the frequency difference increases toward a luminance corresponding to the maximum frequency of the first frequency distribution acquired by the frequency distribution acquisition unit.
Claim 9
Dependent Claim
39 words
The image processing apparatus according to claim 1 , wherein the acquisition unit acquires the information indicating the degree of deviation based on a frequency difference for each luminance between the first frequency distribution and the second frequency distribution.
Claim 10
Dependent Claim
39 words
The image processing apparatus according to claim 8 , wherein the acquisition unit acquires the information indicating the degree of deviation by accumulating the frequency difference for each luminance between the first frequency distribution and the second frequency distribution.
Claim 11
Dependent Claim
53 words
The image processing apparatus according to claim 9 , wherein the acquisition unit acquires the information indicating the degree of deviation by accumulating the frequency difference for each luminance between the first frequency distribution and the second frequency distribution corresponding to a higher luminance than a minimum luminance of the second frequency distribution.
Claim 12
Dependent Claim
41 words
The image processing apparatus according to claim 9 , wherein the acquisition unit executes the accumulation according to a weight for the frequency difference, and the weight increases toward a luminance corresponding to the maximum frequency of the first frequency distribution.
Claim 13
Dependent Claim
34 words
The image processing apparatus according to claim 1 , further comprising a printing unit configured to perform printing using the image data on which a process using the corrected second frequency distribution is performed.
Claim 14
Dependent Claim
166 words
A luminance correction method executed by an image processing apparatus, the method comprising: an image data acquisition step of acquiring image data by optically reading a document; a frequency distribution acquisition step of acquiring a first frequency distribution of luminances from the image data acquired in the image data acquisition step; a generation step of generating a second frequency distribution of luminances of a background of the document using a maximum frequency of the first frequency distribution acquired in the frequency distribution acquisition step as a maximum frequency of the second frequency distribution of luminances of the background of the document; an acquisition step of acquiring information indicating a degree of deviation of the second frequency distribution from the first frequency distribution; a correction step of correcting the second frequency distribution based on the information indicating the degree of deviation acquired in the acquisition step; and an image processing step of processing the image data using the corrected second frequency distribution generated in the generation step.
Claim 15
Dependent Claim
166 words
A luminance correction method executed by an image processing apparatus, the method comprising: an image data acquisition step of acquiring image data by optically reading a document; a frequency distribution acquisition step of acquiring a first frequency distribution of luminances from the image data acquired in the image data acquisition step; a generation step of generating a second frequency distribution of luminances of a background of the document using a maximum frequency of the first frequency distribution acquired in the frequency distribution acquisition step as a maximum frequency of the second frequency distribution of luminances of the background of the document; an acquisition step of acquiring information indicating a degree of deviation of the second frequency distribution from the first frequency distribution; a correction step of correcting the second frequency distribution based on the information indicating the degree of deviation acquired in the acquisition step; and an image processing step of processing the image data using the corrected second frequency distribution generated in the generation step.
Claim 16
Dependent Claim
37 words
The method according to claim 13 , wherein the acquisition step acquires the information indicating the degree of deviation based on a frequency difference for each luminance between the first frequency distribution and the second frequency distribution.
Claim 17
Dependent Claim
37 words
The method according to claim 14 , wherein the acquisition unit acquires the information indicating the degree of deviation by accumulating the frequency difference for each luminance between the first frequency distribution and the second frequency distribution.
Claim 18
Dependent Claim
51 words
The method according to claim 15 , wherein the acquisition unit acquires the information indicating the degree of deviation by accumulating the frequency difference for each luminance between the first frequency distribution and the second frequency distribution corresponding to a higher luminance than a minimum luminance of the second frequency distribution.
Claim 19
Dependent Claim
39 words
The method according to claim 15 , wherein the acquisition unit executes the accumulation according to a weight for the frequency difference, and the weight increases toward a luminance corresponding to the maximum frequency of the first frequency distribution.
Claim 20
Dependent Claim
32 words
The method according to claim 13 , further comprising a printing unit configured to perform printing using the image data on which a process using the corrected second frequency distribution is performed.
Claim 21
Dependent Claim
167 words
A non-transitory computer-readable storage medium storing a program for causing a computer to execute: an image data acquisition step of acquiring image data by optically reading a document; a frequency distribution acquisition step of acquiring a first frequency distribution of luminances from the image data acquired in the image data acquisition step; a generation step of generating a second frequency distribution of luminances of a background of the document using a maximum frequency of the first frequency distribution acquired in the frequency distribution acquisition step as a maximum frequency of the second frequency distribution of luminances of the background of the document; an acquisition step of acquiring information indicating a degree of deviation of the second frequency distribution from the first frequency distribution; a correction step of correcting the second frequency distribution based on the information indicating the degree of deviation acquired in the acquisition step; and an image processing step of processing the image data using the corrected second frequency distribution generated in the generation step.
Claim 22
Dependent Claim
167 words
A non-transitory computer-readable storage medium storing a program for causing a computer to execute: an image data acquisition step of acquiring image data by optically reading a document; a frequency distribution acquisition step of acquiring a first frequency distribution of luminances from the image data acquired in the image data acquisition step; a generation step of generating a second frequency distribution of luminances of a background of the document using a maximum frequency of the first frequency distribution acquired in the frequency distribution acquisition step as a maximum frequency of the second frequency distribution of luminances of the background of the document; an acquisition step of acquiring information indicating a degree of deviation of the second frequency distribution from the first frequency distribution; a correction step of correcting the second frequency distribution based on the information indicating the degree of deviation acquired in the acquisition step; and an image processing step of processing the image data using the corrected second frequency distribution generated in the generation step.
Claim 23
Dependent Claim
37 words
The medium according to claim 19 , wherein the acquisition unit acquires the information indicating the degree of deviation based on a frequency difference for each luminance between the first frequency distribution and the second frequency distribution.
Claim 24
Dependent Claim
37 words
The medium according to claim 20 , wherein the acquisition unit acquires the information indicating the degree of deviation by accumulating the frequency difference for each luminance between the first frequency distribution and the second frequency distribution.
Claim 25
Dependent Claim
51 words
The medium according to claim 21 , wherein the acquisition unit acquires the information indicating the degree of deviation by accumulating the frequency difference for each luminance between the first frequency distribution and the second frequency distribution corresponding to a higher luminance than a minimum luminance of the second frequency distribution.
Claim 26
Dependent Claim
39 words
The medium according to claim 21 , wherein the acquisition unit executes the accumulation according to a weight for the frequency difference, and the weight increases toward a luminance corresponding to the maximum frequency of the first frequency distribution.
Claim 27
Dependent Claim
32 words
The medium according to claim 19 , further comprising a printing unit configured to perform printing using the image data on which a process using the corrected second frequency distribution is performed.
References Cited (Backward Citations)
JPH09167227A
Cited
US6009213A
Cited
US6608926B1
Cited
US6694051B1
Cited
US7006668B2
Cited
US20010007596A1
Cited
JP2001197308A
Cited
US6813386B2
Cited
US7738030B2
Cited
US7167205B2
Cited
US20130028537A1
Cited
US8306357B2
Cited
US8023764B2
Cited
US7177463B2
Cited
US7433538B2
Cited
US7634153B2
Cited
US7103214B2
Cited
US7432985B2
Cited
US8175155B2
Cited
US8237991B2
Cited
US7924469B2
Cited
US7944588B2
Cited
US8600154B2
Cited
US20140044354A1
Cited
US20140037208A1
Cited
US8675249B2
Cited
US20140010450A1
Cited
US20140010415A1
Cited
US20140010451A1
Cited
US20140010442A1
Cited
US20140013213A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2018-07-20 | 2019-01-19 | 2019-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2022-07-20 | 2023-01-19 | 2023-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2026-07-20 | 2027-01-19 | 2027-07-21 | $7700.00 | Open for Payment |