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Publication numberUS3646336 A
Publication typeGrant
Publication dateFeb 29, 1972
Filing dateSep 30, 1968
Priority dateSep 4, 1964
Publication numberUS 3646336 A, US 3646336A, US-A-3646336, US3646336 A, US3646336A
InventorsGilbert L Hobrough
Original AssigneeItek Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Correlation unit
US 3646336 A
Abstract
A photogrammetric system for automatically registering a pair of photographic images for stereographic inspection. Automatic registration of the photographic images is accomplished by electronically sensing parallaxes between the images, and by transforming the images to accomplish registration. Each of a pair of stereo photographs is scanned in X and Y by a separate flying spot scanner which is driven by X- and Y-raster generators. The output of the flying spot scanners is applied to a separate video processor for controlling and enhancing the image signals and then to a separate cathode-ray tube which is driven in X and Y by the same X- and Y-raster generators. The two cathode-ray tubes comprise the left and right sides of a binocular viewer. The output of each of the flying spot scanners and the X- and Y-raster signals are applied to a correlation system which detects parallax errors and first and second order distortions between corresponding sections of each of the photographic images. The correlation system divides the output signals of the flying spot scanners into different frequency band-pass regions for separate correlation of the components of each of the signals in each band-pass region. The output of the correlation system is applied, via a transformation system, as correction signals to the raster signals driving the flying spot scanners which enables the pair of photographic images to be viewed in registration.
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Description  (OCR text may contain errors)

United States Patent Hobrough [54] CORRELATION UNIT [72] Inventor: Gilbert L. Hobrough, Los Altos, Calif.

[73] Assignee: ltek Corporation, Lexington, Mass.

[22] Filed: Sept. 30, 1968 [21] Appl. No.: 822,085

Related US. Application Data [62] Division of Ser. No. 394,502, Sept. 4, 1964, Pat. No.

[52] U.S.Cl ..235/181,328/109, 328/133, 324/83 D [51] Int. Cl ..G06g 7/19, H03d 13/00 [58] 235/181; 179/15;250/220SP; 328/114, 133, 155, 109, 110; 307/232 [56] References Cited UNITED STATES PATENTS 3,185,957 5/1965 3,185,958 5/1965 3,197,625 7/1965 3,364,311 H1968 3,404,261 10/1968 Jespers et al ..235/1 81 1 Feb.29, 1972 Primary Examiner-Eugene G. Botz Assistant Examiner-Felix D. Gruber Attorneyl-lomer 0. Blair and Robert L. Nathans [57] ABSTRACT A photogrammetric system for automatically registering a pair of photographic images for stereographic inspection. Automatic registration of the photographic images is accomplished by electronically sensing parallaxes between the images, and by transforming the images to accomplish registration. Each of a pair of stereo photographs is scanned in X and Y by a separate flying spot scanner which is driven by X- and Y-raster generators. The output of the flying spot scanners is applied to a separate video processor for controlling and enhancing the image signals and then to a separate cathode-ray tube which is driven in X and Y by the same X- and Y-raster generators. The two cathode-ray tubes comprise the left and right sides of a binocular viewer. The output of each of the flying spot scanners and the X- and Y-raster signals are applied to a correlation system which detects parallax errors and first and second order distortions between corresponding sections of each of the photographic images. The correlation system divides the output signals of the flying spot scanners into different frequency band-pass regions for separate correlation of the components of each of the signals in each band-pass region. The output of the correlation system is applied, via a transformation system, as correction signals to the raster signals driving the flying spot scanners which enables the pair of photographic images to be viewed in registration.

12 Claims, 58 Drawing Figures PIG/ifllf/ON flldl 514N425 77: TINIIOIMlf/OM JYJfIM PAIENTEDFEBZS 1972 3,646,336

SHEET cu 0F 23 I NVENTOR. 6/; iii? 4 flaaiouwy PAIENTEDmzs I972 SHEET USUF 23 I N V E NTOR. 6/4 an 1, #052004 PATENTEDFEB 29 1972 SHEET 110F23 @MEQQX PATENTEDFEB29 I972 SHEET 12UF 23 PATENTEDFEBZQ I972 SHEET 13UF 23 V w? wQww INVENTOR.

/wwew .4. Haaewa/v ham 1 PATENTEDFEBZS I972 3,846,336

sum 17 [1F 23 55$ ib k/ a INVENTOR.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3004464 *Jun 21, 1955Oct 17, 1961Hycon Mfg CompanyStereoplotter
US3011128 *May 29, 1958Nov 28, 1961Westinghouse Electric CorpTriple coincidence detector
US3185957 *Jul 27, 1960May 25, 1965Exxon Production Research CoAnalysis of a seismic signal for detection of a reflected wavelet
US3185958 *Apr 9, 1962May 25, 1965Exxon Production Research CoMethod of continuous wave seismic prospecting
US3197625 *Oct 1, 1958Jul 27, 1965Electro Mechanical Res IncCross correlator
US3364311 *Feb 7, 1964Jan 16, 1968James E. WebbElimination of frequency shift in a multiplex communication system
US3404261 *Mar 6, 1963Oct 1, 1968Int Standard Electric CorpCorrelation apparatus for computing time averages of functions
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3958232 *Jun 14, 1974May 18, 1976Hobrough Gilbert LImage transformation system with variable delay
US6005987 *Oct 16, 1997Dec 21, 1999Sharp Kabushiki KaishaPicture image forming apparatus
US6205364Feb 2, 1999Mar 20, 2001Creo Ltd.Method and apparatus for registration control during processing of a workpiece particularly during producing images on substrates in preparing printed circuit boards
US6493064Feb 28, 2001Dec 10, 2002Creo Il, Ltd.Method and apparatus for registration control in production by imaging
US6567713Jan 16, 2001May 20, 2003Creo Il. LtdMethod and apparatus for registration control during processing of a workpiece, particularly during producing images on substrates in preparing printed circuit boards
US6593066Feb 28, 2001Jul 15, 2003Creo Il. Ltd.Method and apparatus for printing patterns on substrates
EP0837428A2 *Oct 16, 1997Apr 22, 1998Sharp Kabushiki KaishaPicture image forming apparatus
WO2000046730A1 *Jan 19, 2000Aug 10, 2000Creo LtdRegistration control during workpiece processing
Classifications
U.S. Classification708/814, 324/76.82, 327/4
International ClassificationG01C11/00, G08C21/00
Cooperative ClassificationG01C11/00, G08C21/00
European ClassificationG01C11/00, G08C21/00