US5574764A
Expired / Lapsed
US
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Digital brightness detector
Assignee: General Electric Co
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Filing: 1995-06-06
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Granted: 1996-11-12
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Expires: 2015-06-06
Abstract
Abstract A brightness detector is used to control the x-ray exposure and the displayed image level in a diagnostic x-ray imaging system. Initially, a region of interest of an image is specified. The average pixel value within the specified region of interest of the image is then found, ignoring regions below a preselected low signal level threshold. Finally, the average pixel value is fed back to the x-ray generator to control the x-ray exposure. The average pixel value is also used to determine a scaling factor to be applied to the image in order to maintain an optimum brightness level when the desired x-ray exposure cannot be attained.
Inventors
- 👤 Paul R. Granfors
- 👤 Jean C. Morvan
- 👤 Michael A. Juhl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:56
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/70; H04N23/71; H04N23/30; H05; H05G; H05G1/00; H05G1/08; H05G1/26; H05G1/30; H05G1/36; H05G1/60
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
68 words
A method of performing brightness detection for a digital x-ray detector comprising the steps of: specifying a region of interest of an image; finding the average pixel value within the specified region of interest of the image; providing the result of the average pixel value finding to the x-ray generator for control of the x-ray exposure; and using the average pixel value to update a digital scaling factor.
Claim 2
Independent Claim
68 words
A method of performing brightness detection for a digital x-ray detector comprising the steps of: specifying a region of interest of an image; finding the average pixel value within the specified region of interest of the image; providing the result of the average pixel value finding to the x-ray generator for control of the x-ray exposure; and using the average pixel value to update a digital scaling factor.
Claim 3
Dependent Claim
43 words
A method of performing brightness detection as claimed in claim 1 wherein the step of calculating the average pixel value within the specified region of interest of the image further comprises the step of ignoring regions below a preselected low signal level threshold.
Claim 4
Dependent Claim
55 words
A method of performing brightness detection as claimed in claim 1 wherein the step of finding the average pixel value within the specified region of interest of the image further comprises the step of calculating the average pixel value with a lesser weighting of pixels with high signal levels to pixels with low signal levels.
Claim 5
Dependent Claim
45 words
A method of performing brightness detection as claimed in claim 1 wherein the step of finding the average pixel value within the specified region of interest of the image further comprises the step of using a histogrammer/accumulating buffer device to compute the average pixel value.
Claim 6
Dependent Claim
72 words
A method of performing brightness detection as claimed in claim 4 wherein the step of using a histogrammer/accumulating buffer device to compute the average pixel value further comprises the steps of: computing a weighted sum of pixel values within the region of interest and equal to or above a low signal level threshold; and computing a total number of pixels outside the region of interest or below the low signal level threshold.
Claim 7
Dependent Claim
23 words
A method of performing automatic brightness detection as claimed in claim 5 wherein the histogrammer/accumulating buffer is operated in a bin accumulate mode.
Claim 8
Dependent Claim
42 words
A method of performing automatic brightness detection as claimed in claim 1 wherein the step of specifying a region of interest comprises the step of using a mask memory containing a map of pixels to be included in the region of interest.
Claim 9
Dependent Claim
28 words
A method of performing automatic brightness detection as claimed in claim 7 further comprising the step of weighting different areas of the image differently when computing the average.
Claim 10
Dependent Claim
61 words
A method of performing automatic brightness detection as claimed in claim 8 wherein the step of weighting different areas of the image differently further comprises the step of including a greater density of pixels within the mask for regions that are to be weighted more heavily and a smaller density of pixels for regions that are to be weighted less heavily.
Claim 11
Dependent Claim
21 words
A method of performing automatic brightness detection as claimed in claim 1 wherein the region of interest comprises multiple disconnected areas.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-11-12 | 2000-05-13 | 2000-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-11-12 | 2004-05-13 | 2004-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-11-12 | 2008-05-13 | 2008-11-12 | $7700.00 | Window Closed / Lapsed |