US6535648B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mathematical model for gray scale and contrast enhancement of a digital image
Assignee: Intel Corp
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Filing: 1998-12-08
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Granted: 2003-03-18
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Expires: 2018-12-08
Abstract
Abstract What is disclosed is a method that specifies identifying a category to which a pixel belongs and performing integrated contrast enhancement and gray scale adjustment on the pixel in accordance with the identified category. These enhanced/adjusted values may be looked up in a table constructed to contain a mapping for all such values.
Inventors
- 👤 Tinku Acharya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:11
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H04N5/20; G; G06; G06T; G06T5/00; G06T5/90
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
85 words
A method comprising: classifying a plurality of pixel categories by determining a set of cut-off values, said cut-off values defining distinct intensity ranges; initializing a plurality of contrast enhancement parameters; initializing a plurality of gray scale adjustment parameters; identifying a category to which a pixel belongs; and performing contrast enhancement and gray scale adjustment on said pixel in accordance with said identified category wherein for each category said parameters and said cut-off values are utilized in a different manner to achieve said enhancement and adjustment.
Claim 2
Independent Claim
85 words
A method comprising: classifying a plurality of pixel categories by determining a set of cut-off values, said cut-off values defining distinct intensity ranges; initializing a plurality of contrast enhancement parameters; initializing a plurality of gray scale adjustment parameters; identifying a category to which a pixel belongs; and performing contrast enhancement and gray scale adjustment on said pixel in accordance with said identified category wherein for each category said parameters and said cut-off values are utilized in a different manner to achieve said enhancement and adjustment.
Claim 3
Dependent Claim
21 words
A method according to claim 1 further comprising: replacing said pixel with an enhanced and adjusted pixel resulting from said performance.
Claim 4
Dependent Claim
18 words
A method according to claim 1 wherein said enhancement parameters are multipliers and said adjustment parameters are exponents.
Claim 5
Dependent Claim
29 words
A method according to claim 1 wherein three categories are defined by two cut-off values, and for pixels belonging to one of the categories no gray scale adjustment occurs.
Claim 6
Dependent Claim
22 words
A method according to claim 1 further comprising: constructing a look-up table mapping all possible intensity values to enhanced and adjusted values.
Claim 7
Dependent Claim
28 words
A method according to claim 5 wherein the performing of enhancement and adjustment includes looking up for each pixel of an image its corresponding enhanced and adjusted value.
Claim 8
Dependent Claim
66 words
A method according to claim 5 wherein the constructing comprises: initializing a counting variable representing a possible pixel value; performing said enhancement and adjustment in accordance with the category with which said counting variable is identified; storing into said table the enhanced/adjusted value resulting from said application; incrementing said counting variable; and repeating said applying, storing and incrementing for each possible intensity value of the variable.
Claim 9
Dependent Claim
97 words
A machine-readable medium having data stored thereon that when accessed by a machine cause the machine to perform operations comprising: initializing contrast enhancement and gray scale adjustment parameters; identifying a category to which a pixel belongs based on a plurality of pixel categories that depend on a set of cut-off values, said cut-off values defining distinct intensity ranges; and performing contrast enhancement and gray scale adjustment on said pixel in accordance with said identified category wherein for each category said parameters and said cut-off values are utilized in a different manner to achieve said enhancement and adjustment.
Claim 10
Dependent Claim
97 words
A machine-readable medium having data stored thereon that when accessed by a machine cause the machine to perform operations comprising: initializing contrast enhancement and gray scale adjustment parameters; identifying a category to which a pixel belongs based on a plurality of pixel categories that depend on a set of cut-off values, said cut-off values defining distinct intensity ranges; and performing contrast enhancement and gray scale adjustment on said pixel in accordance with said identified category wherein for each category said parameters and said cut-off values are utilized in a different manner to achieve said enhancement and adjustment.
Claim 11
Dependent Claim
31 words
The machine readable medium of claim 8 , further comprising data that when accessed cause the machine to: replace said pixel with an enhanced and adjusted pixel resulting from said performance.
Claim 12
Dependent Claim
31 words
The machine readable medium of claim 8 , further comprising data that when accessed cause the machine to: identify and perform said enhancement and adjustment upon all pixels in an image.
Claim 13
Dependent Claim
23 words
The machine readable medium of claim 8 , wherein the stored data are such that three categories are defined by two cut-off values.
Claim 14
Dependent Claim
32 words
The machine readable medium of claim 8 , further comprising data that when accessed cause the machine to: construct a look-up table mapping all possible intensity values to enhanced and adjusted values.
Claim 15
Dependent Claim
36 words
The machine readable medium of claim 12 , wherein the stored data are such that the performing of enhancement and adjustment includes looking up for each pixel of an image its corresponding enhanced and adjusted value.
Claim 16
Dependent Claim
70 words
The machine readable medium of claim 12 , wherein the stored data are such that said constructing comprises: initializing a counting variable; performing said enhancement and adjustment in accordance with a category with which said counting variable is identified; storing into said table an enhanced/adjusted value resulting from said application; incrementing said counting variable; and repeating said applying, said storing and said incrementing for each possible value of the variable.
Claim 17
Independent Claim
112 words
A system comprising: a camera having an image sensor to capture a digital image, a memory to store data and a processor coupled to said memory, the processor to access said data to initialize a plurality of contrast enhancement parameters; initialize a plurality of gray scale adjustment parameters; identify a category to which a pixel of the digital image belongs from a plurality of distinct intensity ranges defined by a set of cut-off values; perform contrast enhancement and gray scale adjustment on said pixel in accordance with said identified category wherein for each category said parameters and said cut-off values are applied in a different manner to achieve said enhancement and adjustment.
Claim 18
Independent Claim
112 words
A system comprising: a camera having an image sensor to capture a digital image, a memory to store data and a processor coupled to said memory, the processor to access said data to initialize a plurality of contrast enhancement parameters; initialize a plurality of gray scale adjustment parameters; identify a category to which a pixel of the digital image belongs from a plurality of distinct intensity ranges defined by a set of cut-off values; perform contrast enhancement and gray scale adjustment on said pixel in accordance with said identified category wherein for each category said parameters and said cut-off values are applied in a different manner to achieve said enhancement and adjustment.
Claim 19
Dependent Claim
30 words
The system according to claim 15 , wherein the memory has further data that when accessed cause: replacing said pixel with an enhanced and adjusted pixel resulting from said performance.
Claim 20
Dependent Claim
30 words
The system according to claim 15 , wherein the memory has further data that when accessed cause: identifying and performing said enhancement and adjustment upon all pixels in said image.
Claim 21
Dependent Claim
22 words
The system according to claim 15 , wherein the stored data are such that three categories are defined by two cut-off values.
Claim 22
Independent Claim
124 words
A method for creating a look-up table adapted to provide an enhanced and adjusted value corresponding to an intensity value of a given pixel, comprising: initializing a counting variable; applying contrast enhancement and gray scale adjustment, in accordance with a category with which said counting variable is identified, said category being one of a plurality defined by a set of cut-off values defining distinct intensity ranges, wherein for each category, a different function of contrast enhancement and gray scale parameters and the cut-off values are applied to achieve said enhancement and adjustment; storing into a table an enhanced/adjusted value resulting from said application; incrementing said counting variable; and repeating said applying, said storing and said incrementing operations for each possible value of the variable.
Claim 23
Independent Claim
124 words
A method for creating a look-up table adapted to provide an enhanced and adjusted value corresponding to an intensity value of a given pixel, comprising: initializing a counting variable; applying contrast enhancement and gray scale adjustment, in accordance with a category with which said counting variable is identified, said category being one of a plurality defined by a set of cut-off values defining distinct intensity ranges, wherein for each category, a different function of contrast enhancement and gray scale parameters and the cut-off values are applied to achieve said enhancement and adjustment; storing into a table an enhanced/adjusted value resulting from said application; incrementing said counting variable; and repeating said applying, said storing and said incrementing operations for each possible value of the variable.
Claim 24
Dependent Claim
23 words
The method according to claim 19 , further comprising: looking up for each pixel in an image its corresponding enhanced and adjusted value.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2006-03-17 | 2006-09-16 | 2007-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-03-17 | 2010-09-16 | 2011-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-03-17 | 2014-09-16 | 2015-03-18 | $7700.00 | Window Closed / Lapsed |