US4472786A
Expired / Lapsed
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Analog Gaussian convolver
Assignee: United States Department of the Navy
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Filing: 1982-04-23
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Granted: 1984-09-18
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Expires: 2002-04-23
Abstract
Abstract An analog Gaussian convolver for performing high speed convolutions of arrary functions (e.g. image arrays) with masks or operators which uses two units of 2-dimensional Gaussians G(u,v) and the like. The output of the two units are subtracted to obtain difference of Gaussian operators (DOG), a very important parameter in computer vision. Input data in the form of a 2-dimensional digital array representing image pixels from the image array is converted into analog form and is then convolved with a 1-dimensional Gaussian operator in a first direction and the result is clocked into a tapped analog delay line. The outputs of the analog tapped delay line are also convolved with another (normally identical) 1-dimensional Gaussian operator in a direction normal to the first direction. The results so obtained represents the convolution of the image with a 2-dimensional Gaussian operator in a channel. By duplicating the two 1-dimensional convolvers and driving a second channel with the same rastering window, the image can be simultaneously convolved with another Gaussian operator and obtaining convolution with a DOG which is useful in a computer vision system for edge detection and binocular stereo.
Inventors
- 👤 Noble G. Larson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:49
CPC Classifications
G; G06; G06J; G06J1/00; G06J1/005
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
209 words
An analog convolver for processing an image in the form of a digital 2-dimensional array representing image pixels using a computer vision system which comprises: first means for converting digital imput information from the digital 2-dimensional image array into an analog form; means for convolving in a first direction the input information from the 2-dimensional image array in the analog form using a first 1-dimensional symmetric function and for producing an output current thereof; second means for converting the output current of said means for convolving to a corresponding voltage output; means for simultaneous storing and convolving, using the first 1-dimenstional function, the output of said second means for converting the output current of said means for convolving in a direction normal to said first direction and producing an output representing convolution of said image array using a first 2-dimensional symmetric function; means for producing an output representing convolution of said image array using a second 2-dimensional symmetric function; and means for subtracting the output representing convolution of said image array using said first 2-dimensional symmetric function and the output representing convolved image array using said second 2-dimensional symmetric function and obtaining a convolved image array using the difference of the first and the second two 2-dimensional symmetric functions.
Claim 2
Dependent Claim
209 words
An analog convolver for processing an image in the form of a digital 2-dimensional array representing image pixels using a computer vision system which comprises: first means for converting digital imput information from the digital 2-dimensional image array into an analog form; means for convolving in a first direction the input information from the 2-dimensional image array in the analog form using a first 1-dimensional symmetric function and for producing an output current thereof; second means for converting the output current of said means for convolving to a corresponding voltage output; means for simultaneous storing and convolving, using the first 1-dimenstional function, the output of said second means for converting the output current of said means for convolving in a direction normal to said first direction and producing an output representing convolution of said image array using a first 2-dimensional symmetric function; means for producing an output representing convolution of said image array using a second 2-dimensional symmetric function; and means for subtracting the output representing convolution of said image array using said first 2-dimensional symmetric function and the output representing convolved image array using said second 2-dimensional symmetric function and obtaining a convolved image array using the difference of the first and the second two 2-dimensional symmetric functions.
Claim 3
Dependent Claim
24 words
The analog convolver of claim 1 wherein said first 1-dimensional symmetric function and said second 1-dimensional symmetric function are of generally identical mathematical configuration.
Claim 4
Dependent Claim
26 words
The analog convolver of claim 1 wherein said first 1-dimensional symmetric function and said second 1-dimensional symmetric function are cross sections of a 2-dimensional Gaussian function.
Claim 5
Dependent Claim
29 words
The analog convolver of claim 3 wherein said means for converting digital input information from the 2-dimensional image array into an analog form includes a plurality of digital-to-analog converters.
Claim 6
Dependent Claim
46 words
The analog convolver of claim 4 wherein said means for convolving in a first direction the input information from the 2-dimensional image array in the analog form includes means for providing a plurality of reference currents representing various values of the first 1-dimensional symmetric Gaussian function.
Claim 7
Dependent Claim
29 words
The analog convolver of claim 5 wherein said means for simultaneous storing and convolving includes a tapped analog delay line for sequentially storing the output of said third means.
Claim 8
Dependent Claim
37 words
An analog convolver of claim 6 wherein said means for simultaneous storing and convolving further includes a plurality of voltage dividers for generating values to convolve the image array in a direction normal to the first direction.
References Cited (Backward Citations)
US4347580A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-09-18 | 1988-03-19 | 1988-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-18 | 1992-03-19 | 1992-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-18 | 1996-03-19 | 1996-09-18 | $7700.00 | Window Closed / Lapsed |