Patent US3992178A successfully refreshed from Google Patents.
EP0117154A2
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Multiple measurement noise reducing system using artifact edge identification and selective signal processing
Assignee: Leland Stanford Junior University
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Filing: 1984-02-21
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Granted: —
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Expires: 2004-02-21
Abstract
Abstract Disclosed is a multiple measurement multiple energy x-ray imaging system in which a plurality of measurements are processed to provide a first image signal representing a desired parameter of an object and in which the plurality of measurements are processed to provide a second processed image signal having greater signal-to-noise ratio than the first processed image signal but in which extraneous artifacts may be introduced into the signal. The spatial location of the edges of the extraneous artifacts are determined. The first processed image signal and the second processed image signal are combined to provide an improved image signal except at the spatial locations of the extraneous artifacts where the first processed image signal is used for the image signal thereby eliminating the extraneous artifact from the displayed image:
Inventors
- 👤 Dwight George Nishimura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 16:22
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/02; G01N23/04; H; H04; H04N; H04N23/00; H04N23/30
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
171 words
In an imaging system, apparatus for reducing extraneous image signals in a processed image signal of an object representing a desired parameter derived from a plurality of measurements comprising: first processing means for processing said plurality of measurements and producing a first processed image signal representing said desired parameter, second processing means for processing said plurality of measurements and producing a second processed image signal having a greater signal-to-noise ratio from said first processed image signal, first filter means for receiving and low pass filtering said first processed image signal, second filter means for receiving and high pass filtering said second processed image signal, means for combining said filtered first processed image signal and said filtered second processed image signal to produce a combined image signal, means for determining the spatial location of edges of extraneous images in said second processed image signal, and means for switching from said combined image signal to a signal based on said first processed image signal in response to detection of edges of extraneous images.
Claim 2
Dependent Claim
171 words
In an imaging system, apparatus for reducing extraneous image signals in a processed image signal of an object representing a desired parameter derived from a plurality of measurements comprising: first processing means for processing said plurality of measurements and producing a first processed image signal representing said desired parameter, second processing means for processing said plurality of measurements and producing a second processed image signal having a greater signal-to-noise ratio from said first processed image signal, first filter means for receiving and low pass filtering said first processed image signal, second filter means for receiving and high pass filtering said second processed image signal, means for combining said filtered first processed image signal and said filtered second processed image signal to produce a combined image signal, means for determining the spatial location of edges of extraneous images in said second processed image signal, and means for switching from said combined image signal to a signal based on said first processed image signal in response to detection of edges of extraneous images.
Claim 3
Dependent Claim
44 words
Apparatus as defined by Claim 1 wherein said means for determining the spatial location of edges includes differential means for determining the components of the spatial gradient signal vector of the difference between said first processed image signal and said second processed image signal.
Claim 4
Dependent Claim
20 words
apparatus as defined by Claim 1 wherein said first filter means and said second filter means are complementary in frequency.
Claim 5
Dependent Claim
38 words
Apparatus as defined by Claim 1 wherein said first processed image signal is derived from a first weighted sum of said measurements and said second processed image signal is derived from a second weighted sum of said measurements.
Claim 6
Dependent Claim
21 words
Apparatus as defined by Claim 4 wherein said imaging system comprises an'x-ray system and said measurements are at different x-ray energies.
Claim 7
Dependent Claim
21 words
Apparatus as defined by Claim 4 wherein said imaging system comprises an x-ray system and said measurements are at different times.
Claim 8
Dependent Claim
106 words
7 . For use in an x-ray imaging system in which a plurality of measurements are made, a method of reducing extraneous signals in a processed image signal comprising the steps of processing said plurality of measurements to provide a first processed image signal representing a desired parameter of an object, processing said plurality of measurements to provide a second processed image signal having greater signal-to-noise ratio than said first processed signal and introducing artifact images, determining the spatial location of edges of said artifacts, and switching from said second processed image signal to said first processed image signal at the spatial location of said artifacts.
Claim 9
Dependent Claim
106 words
7 . For use in an x-ray imaging system in which a plurality of measurements are made, a method of reducing extraneous signals in a processed image signal comprising the steps of processing said plurality of measurements to provide a first processed image signal representing a desired parameter of an object, processing said plurality of measurements to provide a second processed image signal having greater signal-to-noise ratio than said first processed signal and introducing artifact images, determining the spatial location of edges of said artifacts, and switching from said second processed image signal to said first processed image signal at the spatial location of said artifacts.
References Cited (Backward Citations)
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