US3663104A
Expired / Lapsed
US
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Automatic stereoplotting apparatus
Assignee: Northrop Grumman Guidance and Electronics Co Inc
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Filing: 1970-05-19
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Granted: 1972-05-16
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Expires: 1990-05-19
Abstract
Abstract Disclosed in an automatic stereoplotter in which terrain elevation indicating x-parallax corrections are held in response to the absence of a given minimum level of correlatable image detail. This prevents inaccurate, noise responsive x-parallax corrections when traversing image areas such as water bodies having low correlatable information content. To insure a timely restoration of normal operations, a search system responds to a hold of x-parallax correction by systematically searching the stereo model in the x-direction for image areas retaining a sufficient level of correlatable image detail.
Inventors
- 👤 John Montgomery Godfrey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:00
CPC Classifications
G; G01; G01C; G01C11/00
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
266 words
Automatic stereoplotting apparatus comprising: frame means for retaining first and second stereographic images, a first extraction means for extracting image detail information retained by a first discrete area in said first stereographic image and a second extraction means for extracting image detail information retained by a second discrete area in said second stereographic image, correlation means for receiving said extracted image detail information and producing therewith an orthogonal correlation signal dependent upon the degree of misregistration existing between the image detail in said first and second discrete areas and a cross-correlation signal dependent upon the level of correlatable image detail information extracted by said first and second extraction means, profiling drive means for producing a given sense of relative movement between said first stereographic image and said first extraction means and the same sense of relative movement between said second stereographic image and said second extraction means so as to continuously and simultaneously change in each of said first and second images said discrete areas from which information is extracted, registration means receiving said orthogonal correlation signal and producing in response thereto a different sense of relative movement between said first stereographic image and said first extraction means than between said second stereographic image and said second extraction means, condition responsive means for inactivating said registration means in response to a given level of said cross-correlation signal condition, and search means activated by said condition responsive means to produce a different sense of relative movement between said first stereographic image and said first extraction means than between said second stereographic image and said second extraction means.
Claim 2
Dependent Claim
266 words
Automatic stereoplotting apparatus comprising: frame means for retaining first and second stereographic images, a first extraction means for extracting image detail information retained by a first discrete area in said first stereographic image and a second extraction means for extracting image detail information retained by a second discrete area in said second stereographic image, correlation means for receiving said extracted image detail information and producing therewith an orthogonal correlation signal dependent upon the degree of misregistration existing between the image detail in said first and second discrete areas and a cross-correlation signal dependent upon the level of correlatable image detail information extracted by said first and second extraction means, profiling drive means for producing a given sense of relative movement between said first stereographic image and said first extraction means and the same sense of relative movement between said second stereographic image and said second extraction means so as to continuously and simultaneously change in each of said first and second images said discrete areas from which information is extracted, registration means receiving said orthogonal correlation signal and producing in response thereto a different sense of relative movement between said first stereographic image and said first extraction means than between said second stereographic image and said second extraction means, condition responsive means for inactivating said registration means in response to a given level of said cross-correlation signal condition, and search means activated by said condition responsive means to produce a different sense of relative movement between said first stereographic image and said first extraction means than between said second stereographic image and said second extraction means.
Claim 3
Dependent Claim
25 words
Automatic stereoplotting apparatus according to claim 1 wherein said search means produces oscillating relative movement between said first stereographic image and said first extraction means.
Claim 4
Dependent Claim
50 words
Automatic stereoplotting apparatus according to claim 1 wherein said given sense of relative movement produced by said profiling drive means is rectilinear and said senses of relative movement produced by both said registration means and said search means are both rectilinear and transverse to said given sense of relative movement.
Claim 5
Dependent Claim
55 words
Automatic stereoplotting apparatus according to claim 1 wherein said first and second extraction means comprise first and second scanning beams directed through said first and second stereographic images by beam producing means, and said first and second discrete areas comprise the scanning patterns generated on said first and second images by said beam producing means.
Claim 6
Dependent Claim
25 words
Automatic stereoplotting apparatus acCording to claim 4 wherein said search means produces oscillating relative movement between said first stereographic image and said first extraction means.
Claim 7
Dependent Claim
50 words
Automatic stereoplotting apparatus according to claim 5 wherein said given sense of relative movement produced by said profiling drive means is rectilinear and said senses of relative movement produced by both said registration means and said search means are both rectilinear and transverse to said given sense of relative movement.
Claim 8
Dependent Claim
74 words
Automatic stereoplotting apparatus according to claim 4 wherein said profiling drive means comprises an x-y carriage supporting said first and second stereographic images and adapted for movement in orthogonally related x and y directions to produce said given sense of relative movement between said stereographic images and said scanning beams, and said registration means comprises image displacement means for inducing displacement between said first and second images in response to said orthogonal correlation signal.
Claim 9
Dependent Claim
28 words
Automatic stereoplotting apparatus according to claim 7 wherein said search means responds to said condition responsive means by inducing relative movement between said first and second scanning beams.
Claim 10
Dependent Claim
31 words
Automatic stereoplotting apparatus according to claim 8 wherein the relative movements produced by both said image displacement means and said search means coincide with one of said x and y directions.
Claim 11
Dependent Claim
22 words
Automatic stereoplotting apparatus according to claim 9 wherein said search means produces oscillating relative movement between said first and second scanning beams.
Claim 12
Dependent Claim
76 words
Automatic stereoplotting apparatus according to claim 10 wherein said cross-correlation means further produces an signal comprises an x-cross-correlation signal dependent upon the level of correlatable image detail detected in said first and second discrete areas by said first and second scanning beams while scanning in said x-direction, and said condition responsive means activates said search means in response to the absence of a given minimum level of correlatable image detail as indicated by said x-cross-correlation signal.
Claim 13
Dependent Claim
26 words
Automatic stereoplotting apparatus according to claim 11 wherein the relative movements produced by both said image displacement means and said search means coincide with said x-direction.
Claim 14
Dependent Claim
66 words
Automatic stereoplotting apparatus according to claim 12 wherein said search means comprises waveform generator means for generating a triangular waveform, said beam producing means comprise deflection means for producing deflection of said scanning beams in said x and y directions, and said search means applies said triangular waveform to said deflection means so as to produce said relative movement between said first and second scanning beams.
Claim 15
Dependent Claim
44 words
Automatic stereoplotting apparatus according to claim 13 wherein said condition responsive means comprises first time delay means for delaying the activation of said search means for a given predetermined period after detection of said given minimum level of correlatable image detail in said x-direction.
Claim 16
Dependent Claim
99 words
Automatic stereoplotting apparatus according to claim 14 wherein said correlation means further produces a y-cross-correlation signal dependent upon the level of correlatable image detail detected in said first and second discrete areas by said first and second scanning beams while scanning in said y-direction, and said condition responsive means comprises a second time delay means for activating said search means after a delay period less than said given predetermined period in response to the simultaneous absence of given minimum levels of correlatable image detail in both said x and y directions as indicated by said x- and y-cross-correlation signals.
Claim 17
Dependent Claim
24 words
Automatic stereoplotting apparatus according to claim 15 wherein said condition responsive means comprises threshold detector means connected to receive said x- and y-cross-correlation signals.
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) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |