US4356398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of processing radiographic image
Assignee: Fujifilm Holdings Corp
•
Filing: 1980-07-11
•
Granted: 1982-10-26
•
Expires: 2000-07-11
Abstract
Abstract In a radiographic image recording system in which a stimulable phosphor plate is exposed to X-rays to record a radiographic latent image therein, the stimulable phosphor plate is exposed to stimulating rays thereafter to emit light according to the stored energy of X-rays, and the emitted light is detected by a photodetector and converted to an image signal to be used for finally recording a visible image on a photosensitive film or the like, a plurality of stimulable phosphor plates are used for recording radiographic images of an object viewed from the same direction. The image signals read out from the plurality of stimulable phosphor plates are superposed to obtain an averaged image signal. The averaged image signal is then subjected to a gradation process for enhancing the contrast of the image.
Inventors
- 👤 Takao Komaki
- 👤 Seiji Matsumoto
- 👤 Masamitsu Ishida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:50
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/16
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
153 words
A method of processing a radiographic image in a radiographic image recording system in which a stimulable phosphor plate is exposed to X-rays passing through an object to record a radiographic latent image of the object in the form of energy of X-rays stored therein, the stimulable phosphor plate is then exposed to stimulating rays to emit light according to the energy of X-rays stored therein, the emitted light is detected by a photodetecting means and converted to an image signal and the image signal is used for recording a visible image on another recording material, said processing method comprising recording images of the same object from the same direction on a plurality of said stimulable phosphor plates, superposing the image signals obtained from the plurality of stimulable phosphor plates to obtain an image signal having averaged image information, and enhancing the contrast of said image signal thus obtained by a gradation processing.
Claim 2
Independent Claim
153 words
A method of processing a radiographic image in a radiographic image recording system in which a stimulable phosphor plate is exposed to X-rays passing through an object to record a radiographic latent image of the object in the form of energy of X-rays stored therein, the stimulable phosphor plate is then exposed to stimulating rays to emit light according to the energy of X-rays stored therein, the emitted light is detected by a photodetecting means and converted to an image signal and the image signal is used for recording a visible image on another recording material, said processing method comprising recording images of the same object from the same direction on a plurality of said stimulable phosphor plates, superposing the image signals obtained from the plurality of stimulable phosphor plates to obtain an image signal having averaged image information, and enhancing the contrast of said image signal thus obtained by a gradation processing.
Claim 3
Dependent Claim
35 words
A method of processing a radiographic image as defined in claim 1 wherein said plurality of stimulable phosphor plates are simultaneously exposed to the X-rays to record the images of the same object at once.
Claim 4
Dependent Claim
29 words
A method of processing a radiographic image as defined in claim 2 wherein said plurality of stimulable phosphor plates are stacked together and exposed to the X-rays at once.
Claim 5
Dependent Claim
23 words
A method of processing a radiographic image as defined in claim 1 wherein said stimulable phosphor plate is a self-supporting stimulable phosphor plate.
Claim 6
Dependent Claim
29 words
A method of processing a radiographic image as defined in claim 4 wherein the thickness of said self-supporting stimulable phosphor plate is within the range of 100 to 400μ.
Claim 7
Dependent Claim
77 words
A method of processing a radiographic image as defined in claim 1 wherein the number of said plurality of stimulable phosphor plates is 3, and the degree of contrast enhancement of the image signal represented by the ratio (ΔD/ΔlogE) of the optical density difference (ΔD) to the emitted light amount difference in logarithm (ΔlogE) of the finally obtained image is within the range of 3 to 18 in the range of optical density of 0.5 to 1.5.
Claim 8
Dependent Claim
79 words
A method of processing a radiographic image as defined in claim 1 wherein the number of said plurality of stimulable phosphor plates if 4 or more, and the degree of contrast enhancement of the image signal represented by the ratio (ΔD/ΔlogE) of the optical density difference (ΔD) to the emitted light amount difference in logarithm (ΔlogE) of the finally obtained image is within the range of 3 to 20 in the range of optical density of 0.5 to 1.5.
Claim 9
Dependent Claim
28 words
A method of processing a radiographic image as defined in claim 1 wherein said plurality of stimulable phosphor plates are exposed to X-rays by a slit exposure method.
Claim 10
Dependent Claim
23 words
A method of processing a radiographic image as defined in claim 1 wherein said contrast enhancement is conducted for the whole image contrast.
Claim 11
Dependent Claim
24 words
A method of processing a radiographic image as defined in claim 1 wherein said contrast enhancement is conducted for only a particular frequency component.
Claim 12
Dependent Claim
38 words
A method of processing a radiographic image as defined in claim 10 wherein said particular frequency component is above a super-low frequency of the radiographic image or of the image obtained by the superposition of said image signals.
Claim 13
Dependent Claim
72 words
A method of processing a radiographic image as defined in claim 11 wherein said contrast enhancement of the particular frequency component is performed by an unsharp masking processing in which an unsharp mask signal Sus corresponding to said super-low frequency is obtained and an operation represented by a formula Sorg +β(Sorg-Sus), where Sorg is an original image signal and β is an emphasis coefficient, is conducted for every point of the image.
Claim 14
Dependent Claim
36 words
A method of processing a radiographic image as defined in claim 12 wherein said unsharp mask has a modulation transfer function of 0.5 or less in the super-low spatial frequency range of 0.5 to 0.01 cycle/mm.
Claim 15
Dependent Claim
26 words
A method of processing a radiographic image as defined in claim 12 wherein said emphasis coefficient β is changed according to the original image signal Sorg.
References Cited (Backward Citations)
US1609703A
Cited
US3975637A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-10-25 | 1986-04-26 | 1986-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-25 | 1990-04-26 | 1990-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-25 | 1994-04-26 | 1994-10-26 | $7700.00 | Window Closed / Lapsed |