Patent US6832009B1 successfully refreshed from Google Patents.
US6832009B1
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Method and apparatus for improved image interpolation
Assignee: Qualcomm Technologies International Ltd
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Filing: 1999-09-24
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Granted: 2004-12-14
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Expires: 2019-09-24
Abstract
Abstract A method and apparatus for image interpolation provides a simple method that can up-scale an image in various scale ratios, including fractional scaling ratios, and can yield a sharp image with reduced unpleasant visual artifacts. An embodiment uses a power weight function that is gradient dependent and uses a function that has a linear dependence on the distance to compute interpolated pixels. A further embodiment uses a power that can be adapted according to the local contrast of edges.
Inventors
- 👤 Nira Shezaf
- 👤 Hagit Abramov-Segal
- 👤 Ilan Sutskover
- 👤 Ran Bar-Sella
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 23:04
CPC Classifications
G; G06; G06T; G06T3/00; G06T3/40; G06T3/403
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
80 words
A method for determining an interpolated pixel value comprising: determining a plurality of gradient values for a plurality of original pixels near said interpolated pixel; determining a plurality of distance values for a plurality of original pixels near said interpolated pixel; combining a plurality of original pixel values, at least some of said original pixel values adjusted by said gradient values and said distance values; and normalizing the result of said combining to produce a value of said interpolated pixel.
Claim 2
Independent Claim
80 words
A method for determining an interpolated pixel value comprising: determining a plurality of gradient values for a plurality of original pixels near said interpolated pixel; determining a plurality of distance values for a plurality of original pixels near said interpolated pixel; combining a plurality of original pixel values, at least some of said original pixel values adjusted by said gradient values and said distance values; and normalizing the result of said combining to produce a value of said interpolated pixel.
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein said gradient value is incorporated into a power function prior to said combining.
Claim 4
Dependent Claim
17 words
The method of claim 2 wherein said power function is adaptive according to local contrast of edges.
Claim 5
Dependent Claim
23 words
The method of claim 1 wherein said distance value has a linear dependence on the distance between said pixel and surrounding prior pixels.
Claim 6
Dependent Claim
15 words
The method of claim 1 wherein said gradient values are computed using a Sobel operation.
Claim 7
Dependent Claim
15 words
The method of claim 1 wherein said gradient values are computed using a Prewitt operation.
Claim 8
Dependent Claim
15 words
The method of claim 1 wherein said gradient values are computed using a Roberts operation.
Claim 9
Dependent Claim
17 words
The method of claim 1 wherein said method is performed by an appropriately configured digital processing device.
Claim 10
Independent Claim
112 words
A method carried out by electronic circuitry for determining a pixel value p(c) of calculated pixel c from the values p(a i ) of surrounding original pixels a i(l to n ) according to an equation of the form: p ( c ) = ∑ i = 1 tol W ( a i ) p ( a i ) ∑ i = 1 tol W ( a i ) where W(a i ) is a function with linear dependence on the distance and dependent on a local gradient, wherein the calculation according to said equation is performed by the electronic circuitry.
Claim 11
Independent Claim
112 words
A method carried out by electronic circuitry for determining a pixel value p(c) of calculated pixel c from the values p(a i ) of surrounding original pixels a i(l to n ) according to an equation of the form: p ( c ) = ∑ i = 1 tol W ( a i ) p ( a i ) ∑ i = 1 tol W ( a i ) where W(a i ) is a function with linear dependence on the distance and dependent on a local gradient, wherein the calculation according to said equation is performed by the electronic circuitry.
Claim 12
Dependent Claim
7 words
The method of claim 9 where 1=4.
Claim 13
Dependent Claim
13 words
The method of claim 9 where W(a i )=D(a i )G′(a i ).
Claim 14
Dependent Claim
24 words
The method of claim 11 wherein D(a i ) is given by an expression of the form: D(a i )=(1−Δx i )(1−Δy i ).
Claim 15
Dependent Claim
22 words
The method of claim 11 wherein G′(a i ) is given by an expression of the form: G′(a i )=(−μG(a i )+1)″.
Claim 16
Dependent Claim
20 words
The method of claim 13 wherein G(a i ) is a gradient value computing from a plurality of surrounding pixels.
Claim 17
Dependent Claim
25 words
The method of claim 13 wherein G(a i ) is a gradient value computing using a convolution kernel from a plurality of surrounding original pixels.
Claim 18
Dependent Claim
18 words
The method of claim 13 wherein G(a i ) is a gradient value computing using a Sobel operator.
Claim 19
Dependent Claim
18 words
The method of claim 13 wherein G(a i ) is a gradient value computing using a Prewitt operator.
Claim 20
Dependent Claim
18 words
The method of claim 13 wherein G(a i ) is a gradient value computing using a Roberts operator.
Claim 21
Dependent Claim
18 words
The method of claim 13 wherein μ is a positive constant value close to and lower than 1.
Claim 22
Dependent Claim
16 words
The method of claim 13 wherein n is a constant value selected for a particular image.
Claim 23
Dependent Claim
19 words
The method of claim 13 wherein n is selected based on the average gradients of edges in said image.
Claim 24
Dependent Claim
24 words
The method of claim 13 wherein n is a value that is selected for a pixel based on the local contrast at said pixel.
Claim 25
Dependent Claim
53 words
The method of claim 22 wherein n is a value that is selected for a pixel based on the local contrast at said pixel according to the formula: n = base_n max ( G ( a 1 ) , … , G ( a k ) ( α )
Claim 26
Dependent Claim
7 words
The method of claim 23 wherein k=4.
Claim 27
Dependent Claim
47 words
The method of claim 23 wherein α is a constant between 0 and 1 and is chosen so that base_n/Alpha is the maximum power and where base_n is a minimum power chosen so that the power fits the highest edge contrast that can be in the image.
Claim 28
Dependent Claim
17 words
The method of claim 23 wherein said method is performed by an appropriately configured digital processing device.
Claim 29
Independent Claim
85 words
A method for determining a pixel value for an interpolating pixel in an image comprising: determining a first sum of a plurality of values of a plurality of surrounding pixels, said plurality of values modified by at least two weighting factors; dividing said first sum by a second sum, said second sum comprising said weighting factors wherein one of said weighting factors is a power weight function that is gradient dependent; and developing an electronic image signal which incorporates the interpolated image pixel value therein.
Claim 30
Independent Claim
85 words
A method for determining a pixel value for an interpolating pixel in an image comprising: determining a first sum of a plurality of values of a plurality of surrounding pixels, said plurality of values modified by at least two weighting factors; dividing said first sum by a second sum, said second sum comprising said weighting factors wherein one of said weighting factors is a power weight function that is gradient dependent; and developing an electronic image signal which incorporates the interpolated image pixel value therein.
Claim 31
Dependent Claim
18 words
The method of claim 27 wherein one of said weighting factors has a linear dependence on the distance.
Claim 32
Dependent Claim
26 words
The method of claim 27 wherein one of said weighting factors is a power weight function that is adaptive according to the local contrast of edges.
Claim 33
Dependent Claim
123 words
A digital image capture device comprising: image capture sensors for capturing an image at a first pixel density; image storage for holding a portion up to all of said captured image; logic components for increasing pixel density and determining the value of an interpolated pixel by: determining a plurality of gradient values for a plurality of original pixels near said interpolated pixel; determining a plurality of distance values for a plurality of original pixels near said interpolated pixel; and combining a plurality of original pixel values, at least some of said original pixel values adjusted by said gradient values and said distance values to produce a value of said interpolated pixel; and an interface for outputting said image at a second pixel density.
Claim 34
Dependent Claim
123 words
A digital image capture device comprising: image capture sensors for capturing an image at a first pixel density; image storage for holding a portion up to all of said captured image; logic components for increasing pixel density and determining the value of an interpolated pixel by: determining a plurality of gradient values for a plurality of original pixels near said interpolated pixel; determining a plurality of distance values for a plurality of original pixels near said interpolated pixel; and combining a plurality of original pixel values, at least some of said original pixel values adjusted by said gradient values and said distance values to produce a value of said interpolated pixel; and an interface for outputting said image at a second pixel density.
Claim 35
Dependent Claim
133 words
An image display device capable of displaying an image with an altered pixel density comprising: an interface for accepting an image at a first pixel density; image storage for holding a portion of said image up to all of said image; logic components for increasing pixel density and determining the value of an interpolated pixel by: determining a plurality of gradient values for a plurality of original pixels near said interpolated pixel; determining a plurality of distance values for a plurality of original pixels near said interpolated pixel; and combining a plurality of original pixel values, at least some of said original pixel values adjusted by said gradient values and said distance values to produce a value of said interpolated pixel; and a display for displaying said image at a second pixel density.
Claim 36
Dependent Claim
133 words
An image display device capable of displaying an image with an altered pixel density comprising: an interface for accepting an image at a first pixel density; image storage for holding a portion of said image up to all of said image; logic components for increasing pixel density and determining the value of an interpolated pixel by: determining a plurality of gradient values for a plurality of original pixels near said interpolated pixel; determining a plurality of distance values for a plurality of original pixels near said interpolated pixel; and combining a plurality of original pixel values, at least some of said original pixel values adjusted by said gradient values and said distance values to produce a value of said interpolated pixel; and a display for displaying said image at a second pixel density.
Claim 37
Dependent Claim
25 words
The device according to claim 30 , wherein the interface for outputting said image causes the second pixel density of said image to be increased.
Claim 38
Dependent Claim
25 words
The device according to claim 31 , wherein the interface for outputting said image causes the second pixel density of said image to be increased.
Claim 39
Dependent Claim
30 words
The method of claim 1 , additionally comprising adding the value of the interpolated pixel to values of the original pixels, thereby to increase the number of values of pixels.
Claim 40
Independent Claim
75 words
A method of determining a value of a given pixel of an image from values of pixels surrounding the given pixel, comprising: summing values of a plurality of said surrounding pixels to determine the value of the given pixel of the image, the summed values being modified by a power weighting function that is adaptive to characteristics of the image, and developing an electronic video signal for displaying the given pixel with the determined value.
Claim 41
Independent Claim
75 words
A method of determining a value of a given pixel of an image from values of pixels surrounding the given pixel, comprising: summing values of a plurality of said surrounding pixels to determine the value of the given pixel of the image, the summed values being modified by a power weighting function that is adaptive to characteristics of the image, and developing an electronic video signal for displaying the given pixel with the determined value.
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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) | 2007-12-14 | 2008-06-14 | 2008-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-12-14 | 2012-06-14 | 2012-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-12-14 | 2016-06-14 | 2016-12-14 | $7700.00 | Window Closed / Lapsed |