US6069979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for compressing the dynamic range of digital projection radiographic images
Assignee: Carestream Health Inc
•
Filing: 1997-11-04
•
Granted: 2000-05-30
•
Expires: 2017-11-04
Abstract
Abstract A method for compressing the dynamic range of a digital radiographic image comprising the steps of: providing an original digital radiographic image; processing the original digital radiographic image with an unsharp masking technique to produce a low frequency digital radiographic image having low frequency components; subtracting the low frequency digital radiographic image from the original digital radiographic image to produce a high frequency digital radiographic image; multiplying the low frequency image by a first gain factor and the high frequency image by a second gain factor to produce respective modified low and high frequency images; combining the modified low and high frequency images with a mid-range image to produce an output digital image; and passing the output digital image through a look-up table to render an image with code values that represent optical density of a printed or displayed rendering of the image.
Inventors
- 👤 Richard L. VanMetter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:14
CPC Classifications
G; G06; G06T; G06T5/00; G06T5/73; G06T5/75; G06T5/90; G06T5/92
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
143 words
A method for compressing the dynamic range of a digital radiographic image comprising the steps of: providing an original digital radiographic image; processing said original digital radiographic image with an unsharp masking technique to produce a low frequency digital radiographic image having low frequency components; subtracting said low frequency digital radiographic image from said original digital radiographic image to produce a high frequency digital radiographic image; multiplying said low frequency image by a first gain factor and said high frequency image by a second gain factor to produce respective modified low and high frequency images; combining said modified low and high frequency images with a mid-range image to produce an output digital image; and passing said output digital image through a look-up table to render an image with code values that represent optical density of a printed or displayed rendering of the image.
Claim 2
Independent Claim
143 words
A method for compressing the dynamic range of a digital radiographic image comprising the steps of: providing an original digital radiographic image; processing said original digital radiographic image with an unsharp masking technique to produce a low frequency digital radiographic image having low frequency components; subtracting said low frequency digital radiographic image from said original digital radiographic image to produce a high frequency digital radiographic image; multiplying said low frequency image by a first gain factor and said high frequency image by a second gain factor to produce respective modified low and high frequency images; combining said modified low and high frequency images with a mid-range image to produce an output digital image; and passing said output digital image through a look-up table to render an image with code values that represent optical density of a printed or displayed rendering of the image.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein said providing step provides a projection digital radiographic image produced by computed radiography or direct digital radiography.
Claim 4
Dependent Claim
60 words
The method of claim 1 wherein said processing step includes convolving the exposure code value data E(i,j) of said original image with a kernel whose dimension is more than 1/40th but less than 1/10th, the size of the short dimension of the image matrix to produce an image E low (i,j) which is an unsharp version of said original image.
Claim 5
Dependent Claim
15 words
The method of claim 3 wherein said subtracting step is expressed as: E.sub.high (i,j)=E(i,j)-E.sub.low (i,j).
Claim 6
Dependent Claim
64 words
The method of claim 4 wherein in said multiplying step said first gain factor is greater than 0 but less than 1, said second gain factor β is greater than 1, and in said combining step, E'(i,j)=αE.sub.low (i,j)+(1-α)E.sub.mid +βE.sub.high (i,j) where E'(i,j) is the output digital image; and Emid is the exposure code value corresponding to the density in the image that remains invariant.
Claim 7
Dependent Claim
171 words
A computer storage product comprising: a digital storage device containing data to be read and used by a computer, said data including a computer program for carrying out a method for compressing the dynamic range of a digital radiographic image comprising the steps of: providing an original digital radiographic image; processing said original digital radiographic image with an unsharp masking technique to produce a low frequency digital radiographic image having low frequency components; subtracting said low frequency digital radiographic image from said original digital radiographic image to produce a high frequency digital radiographic image; multiplying said low frequency image by a first gain factor and said high frequency image by a second gain factor to produce respective modified low and high frequency images; combining said modified low and high frequency images with a mid-range image to produce an output digital image; and passing said output digital image through a look-up table to render an image with code values that represent optical density of a printed or displayed rendering of the image.
Claim 8
Dependent Claim
171 words
A computer storage product comprising: a digital storage device containing data to be read and used by a computer, said data including a computer program for carrying out a method for compressing the dynamic range of a digital radiographic image comprising the steps of: providing an original digital radiographic image; processing said original digital radiographic image with an unsharp masking technique to produce a low frequency digital radiographic image having low frequency components; subtracting said low frequency digital radiographic image from said original digital radiographic image to produce a high frequency digital radiographic image; multiplying said low frequency image by a first gain factor and said high frequency image by a second gain factor to produce respective modified low and high frequency images; combining said modified low and high frequency images with a mid-range image to produce an output digital image; and passing said output digital image through a look-up table to render an image with code values that represent optical density of a printed or displayed rendering of the image.
References Cited (Backward Citations)
US4827528A
Cited
US4941190A
Cited
US5319719A
Cited
US5805721A
Cited
US5461655A
Cited
US5363209A
Cited
US5774599A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-05-30 | 2003-11-29 | 2004-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-05-30 | 2007-11-29 | 2008-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-05-30 | 2011-11-29 | 2012-05-30 | $7700.00 | Window Closed / Lapsed |