US5617461A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the operation of a digital imaging system of an X-ray diagnostic apparatus
Assignee: Siemens AG
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Filing: 1996-07-16
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Granted: 1997-04-01
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Expires: 2016-07-16
Abstract
Abstract In a method for the operation of a digital imaging system of an X-ray diagnostic apparatus having an X-ray unit for the generation of X-ray images, an X-ray image converter-television chain for the acquisition of the X-ray images, the chain including a digital image converter having image points arranged in matrix form in rows and columns and a monitor for the reproduction of the X-ray images processed by the digital imaging system. Defective image points are recognized by converting at least one calibration image into a filter image by highpass filtering, e.g. a median filtering, and the filter image is subjected to defect determination, so that a defect image is obtained. The defect image is used for the correction of an original image.
Inventors
- 👤 Horst Schreiner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:00
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/30; H04N5/32; H04N5/3205; H04N25/00; H04N25/60; H04N25/67; H04N25/671; H04N25/673; H04N25/674; H04N25/68; H04N25/69; H04N5/14; H04N5/21; H04N5/321; H04N5/325
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
115 words
A method for operating a digital imaging system in an x-ray diagnostic apparatus having an x-ray unit for generating x-ray images, an x-ray image converter video chain for converting the x-ray images into video images, the chain including a digital image converter having image points arranged in matrix form in rows and columns, and a monitor for displaying the video images, said method comprising the steps, for recognizing defective image points, of: generating at least one calibration image; converting said calibration image into a filter image by filtering said calibration image; subjecting said filter image to a defect determination procedure and thereby obtaining a defect image; and correcting an original image using said defect image.
Claim 2
Independent Claim
115 words
A method for operating a digital imaging system in an x-ray diagnostic apparatus having an x-ray unit for generating x-ray images, an x-ray image converter video chain for converting the x-ray images into video images, the chain including a digital image converter having image points arranged in matrix form in rows and columns, and a monitor for displaying the video images, said method comprising the steps, for recognizing defective image points, of: generating at least one calibration image; converting said calibration image into a filter image by filtering said calibration image; subjecting said filter image to a defect determination procedure and thereby obtaining a defect image; and correcting an original image using said defect image.
Claim 3
Dependent Claim
32 words
A method as claimed in claim 1 wherein the step of filtering said at least one calibration image comprises high pass filtering said at least one calibration image using a median filter.
Claim 4
Dependent Claim
67 words
A method as claimed in claim 2 wherein the step of high pass filtering said at least one calibration image using a median filter comprises two-dimensionally median filtering said at least one calibration image by first one-dimensionally filtering said at least one calibration image in a first direction, and secondly one-dimensionally filtering said at least one calibration image in a second direction perpendicular to said first direction.
Claim 5
Dependent Claim
29 words
A method as claimed in claim 1 wherein the step of subjecting said filter image to a defect determination procedure comprises calculating a histogram distribution of said filter image.
Claim 6
Dependent Claim
70 words
A method as claimed in claim 4 wherein the step of filtering at least one calibration image comprises highpass filtering at least one calibration image, wherein the step of calculating said histogram distribution of said filter image comprises determining a histogram core of said filter image, and wherein the step of correcting said original image comprises calculating defects of image points of said original image outside of said histogram core.
Claim 7
Dependent Claim
52 words
A method as claimed in claim 1 wherein the step of filtering at least one calibration image comprises low pass filtering said at least one calibration image to obtain a low pass filtered calibration image, and subtracting said low pass filtered calibration image from said calibration image to obtain said filter image.
Claim 8
Dependent Claim
65 words
A method as claimed in claim 6 comprising the additional step of correcting previously-found defects in said calibration image to form a correction image and using said correction image as said at least one calibration image in the filtering of said at least one calibration image, and subjecting said filter image to a threshold comparison for identification of defects therein to obtain said defect image.
Claim 9
Dependent Claim
27 words
A method as claimed in claim 7 comprising the additional step of calculating a threshold for said threshold comparison from a histogram distribution of said filter image.
Claim 10
Dependent Claim
33 words
A method as claimed in claim 6 wherein the step of low pass filtering said at least one calibration image comprises low pass filtering said at least one calibration image using unsharp masking.
Claim 11
Dependent Claim
117 words
A method as claimed in claim 6 comprising the additional step of correcting previously-identified defects in said original image to obtain a corrected image and using said corrected image as said calibration image in the step of filtering said calibration image, and wherein the step of filtering said calibration image comprises low pass filtering said corrected image to obtain a low pass filtered image and forming a difference image which is a difference between said original image and said low pass filtered image, using said difference image as said filtered image in the step of subjecting said filter image to a defect determination, and repeating the above steps if new defects are found in said difference image.
Claim 12
Dependent Claim
26 words
A method as claimed in claim 1 wherein the step of forming at least one calibration image comprises forming a bright image and a dark image.
Claim 13
Dependent Claim
26 words
A method as claimed in claim 1 wherein the step of forming at least one calibration image comprises forming a noise image and a signal image.
Claim 14
Dependent Claim
25 words
A method as claimed in claim 1 wherein the step of forming at least one calibration image comprises forming a series of successive calibration images.
Claim 15
Dependent Claim
32 words
A method as claimed in claim 1 wherein the step of subjecting said filter image to a defect determination comprises identifying defective image points in said filter image within a reference zone.
Claim 16
Dependent Claim
24 words
A method as claimed in claim 1 comprising the step of generating said original image with an x-ray image converter composed of amorphous silicon.
Claim 17
Dependent Claim
26 words
A method as claimed in claim 1 comprising the step of generating said original image with an x-ray image amplifier coupled to a CCD image converter.
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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) | 2000-03-31 | 2000-09-30 | 2001-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-03-31 | 2004-09-30 | 2005-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-03-31 | 2008-09-30 | 2009-04-01 | $7700.00 | Window Closed / Lapsed |