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USH999H
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Transparency distortion measurement process
Assignee: United States Department of the Air Force
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Filing: 1990-09-13
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Granted: 1991-12-03
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Expires: 2010-09-13
Abstract
Abstract A method for measuring optical distortion in a transparency is described which comprises the steps of acquiring an analog image of a grid board through the transparency, digitizing the analog image to form a digitized image comprising a multiplicity of pixels defining the shape of the grid board as viewed through the transparency, locating on the digitized image the pixels defining the grid and determining optical distortion of the transparency by comparing the shape of the grid in the digitized image to the actual grid shape on the grid board.
Inventors
- 👤 Harold S. Merkel
- 👤 Harry L. Task
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:12
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/8851
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
158 words
A method for measuring optical distortion in a transparency, comprising the steps of: (a) providing a grid board having well defined grid lines of preselected spacing thereon; (b) acquiring an analog image of said grid board through a transparency; (c) digitizing said analog image to form a digitized image of said grid board and transparency, said digitized image comprising a multiplicity of pixels defining the shape of said grid as viewed through said transparency; (d) selecting a threshold luminance value for said pixels at or above which threshold luminance value said pixels are assigned an on value and below which threshold luminance value said pixels are assigned an off value; (e) locating on said digitized image the on and off pixels defining said grid lines; and (f) determining the optical distortion of said transparency by comparing the shape of said grid lines in said digitized image to the shape of said preselected grid lines of said grid board.
Claim 2
Independent Claim
158 words
A method for measuring optical distortion in a transparency, comprising the steps of: (a) providing a grid board having well defined grid lines of preselected spacing thereon; (b) acquiring an analog image of said grid board through a transparency; (c) digitizing said analog image to form a digitized image of said grid board and transparency, said digitized image comprising a multiplicity of pixels defining the shape of said grid as viewed through said transparency; (d) selecting a threshold luminance value for said pixels at or above which threshold luminance value said pixels are assigned an on value and below which threshold luminance value said pixels are assigned an off value; (e) locating on said digitized image the on and off pixels defining said grid lines; and (f) determining the optical distortion of said transparency by comparing the shape of said grid lines in said digitized image to the shape of said preselected grid lines of said grid board.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein said step of acquiring said image of said grid board through said transparency is performed utilizing a video camera.
Claim 4
Dependent Claim
43 words
The method of claim 1 wherein the step of locating on said digitized image the on and off pixels defining said grid lines is performed by searching across said digitized image in a direction generally perpendicular to the direction of said grid lines.
Claim 5
Dependent Claim
37 words
The method of claim 1 wherein the step of locating on said digitized image the on and off pixels defining said grid is performed by computer search of the array of said pixels in said digitized image.
Claim 6
Dependent Claim
36 words
The method of claim 1 wherein the step of determining the optical distortion of said transparency is performed by comparing the locations of pixels defining corresponding grid lines in said digitized image and said grid board.
Claim 7
Dependent Claim
32 words
The method of claim 1 further comprising the step of calculating the slope of each of said grid lines of said digitized image as a percentage of the area of said transparency.
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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) | 1994-12-02 | 1995-06-03 | 1995-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-02 | 1999-06-03 | 1999-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-02 | 2003-06-03 | 2003-12-03 | $7700.00 | Window Closed / Lapsed |