Patent US5185671A successfully refreshed from Google Patents.
US5185671A
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Adaptive control of an electronic imaging camera
Assignee: Northrop Grumman Systems Corp
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Filing: 1991-06-21
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Granted: 1993-02-09
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Expires: 2011-06-21
Abstract
Abstract A CCD imaging camera is adaptively controlled by: illuminating a reflectance field of view, selectively sensing a desired image field area within the field of view and generating an image signal thereof, reducing low frequency components of the sensed area image signal, generating a contrast signal from the image signal, generating an average or mean signal from a plurality of image contrast signals, comparing the mean signal with a reference signal corresponding to a predetermined contrast maximum value, and thereafter controlling the light level or the range of the camera to the object field.
Inventors
- 👤 Laurence A. Lieberman
- 👤 Philip Downes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:06
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/70; H04N23/71; H04N7/00; H04N7/18; H04N7/183; H04N7/185; H04N23/74
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
186 words
A method for adaptively adjusting the camera lighting level and distance between a camera and a light reflectance object plane including a reflectance field of view, comprising the steps of: illuminating a reflectance field of view; sensing a desired image field within the reflectance field of view; generating an image signal of said image field; generating a plurality of image parameter signals from the image signal; generating a means image parameter signal from said plurality of image parameter signals; comparing said mean image parameter signal with a predetermined reference signal and generating a difference signal therefrom; initially reducing the camera lighting when the mean image parameter signal is less than said predetermined reference signal, reducing said distance between the camera and the light reflectance object plane when the mean image parameter signal is greater than said predetermined reference signal; thereafter repeating said comparing step; and again reducing the camera lighting when the mean image parameter signal is less than said predetermined reference signal but increasing the camera lighting to a predetermined previous level set when the mean image parameter signal is greater than said reference signal.
Claim 2
Independent Claim
186 words
A method for adaptively adjusting the camera lighting level and distance between a camera and a light reflectance object plane including a reflectance field of view, comprising the steps of: illuminating a reflectance field of view; sensing a desired image field within the reflectance field of view; generating an image signal of said image field; generating a plurality of image parameter signals from the image signal; generating a means image parameter signal from said plurality of image parameter signals; comparing said mean image parameter signal with a predetermined reference signal and generating a difference signal therefrom; initially reducing the camera lighting when the mean image parameter signal is less than said predetermined reference signal, reducing said distance between the camera and the light reflectance object plane when the mean image parameter signal is greater than said predetermined reference signal; thereafter repeating said comparing step; and again reducing the camera lighting when the mean image parameter signal is less than said predetermined reference signal but increasing the camera lighting to a predetermined previous level set when the mean image parameter signal is greater than said reference signal.
Claim 3
Independent Claim
199 words
A method for adaptively adjusting the camera lighting level and distance between a camera and a light reflectance object plane including a reflectance field of view, comprising the steps of: illuminating a reflectance field of view; sensing a desired image field within the reflectance field of view; generating an image signal of said image field; generating a plurality of contrast parameter signals from said image signal, said contrast parameter signals being a function of intensity of luminance of the image field; generating a mean contrast parameter signal; comparing said mean contrast parameter signal with a reference signal corresponding to a predetermined contrast level and generating a contrast difference signal; initially reducing the camera lighting when the mean contrast parameter signal is less than said predetermined contrast level, reducing said distance between the camera and the light reflectance object plane when the mean contrast parameter signal is greater than said predetermined contrast signal; repeating said comparing step; and then reducing the camera lighting when the mean contrast parameter signal is less than said predetermined contrast value but increasing the camera lighting to a predetermined previous level set when the mean contrast parameter signal is greater than said predetermined contrast value.
Claim 4
Independent Claim
199 words
A method for adaptively adjusting the camera lighting level and distance between a camera and a light reflectance object plane including a reflectance field of view, comprising the steps of: illuminating a reflectance field of view; sensing a desired image field within the reflectance field of view; generating an image signal of said image field; generating a plurality of contrast parameter signals from said image signal, said contrast parameter signals being a function of intensity of luminance of the image field; generating a mean contrast parameter signal; comparing said mean contrast parameter signal with a reference signal corresponding to a predetermined contrast level and generating a contrast difference signal; initially reducing the camera lighting when the mean contrast parameter signal is less than said predetermined contrast level, reducing said distance between the camera and the light reflectance object plane when the mean contrast parameter signal is greater than said predetermined contrast signal; repeating said comparing step; and then reducing the camera lighting when the mean contrast parameter signal is less than said predetermined contrast value but increasing the camera lighting to a predetermined previous level set when the mean contrast parameter signal is greater than said predetermined contrast value.
Claim 5
Dependent Claim
27 words
The method of claim 2 wherein said step of generating a mean contrast parameter signal includes the step of reducing low frequency components in said image signal.
Claim 6
Dependent Claim
23 words
The method of claim 3 wherein said step of reducing said low frequency components includes the step of homomorphically filtering said image signal.
Claim 7
Dependent Claim
24 words
The method of claim 3 wherein said step of reducing said low frequency components includes the step of high pass filtering said image signal.
Claim 8
Dependent Claim
38 words
The method of claim 5 and additionally including the step of low pass filtering said image signal, and dividing the high pass filtered image signal by the low pass filtered image signal and generating a normalized image signal.
Claim 9
Dependent Claim
23 words
The method of claim 2 and further including the steps of mounting said camera on a water vehicle and viewing the sea floor.
Claim 10
Dependent Claim
27 words
The method of claim 7 wherein said water vehicle comprises an underwater vehicle and said image area lies on or in the vicinity of the sea floor.
Claim 11
Dependent Claim
12 words
The method of claim 8 wherein said camera comprises an electronic camera.
Claim 12
Dependent Claim
14 words
The method of claim 9 wherein said electronic camera comprises a CCD electronic camera.
Claim 13
Independent Claim
142 words
A method for adaptively adjusting the camera lighting level and distance between a camera and a light reflectance object plane including a reflectance field of view, comprising the steps of: illuminating a reflectance field of view; sensing a desired image field within the reflectance field of view; generating an image signal of said image field; homomorphically filtering said image signal for reducing low frequency components therefrom; generating at least one contrast parameter signal from the filtered image signal, said contrast parameter signal being a function of intensity or luminance of the image field; comparing said at least one contrast parameter signal with a reference signal corresponding to a predetermined contrast level and generating a contrast difference signal; and controlling the light level or the distance between the camera and the light reflectance object plane as a function of said contrast difference signal.
Claim 14
Independent Claim
142 words
A method for adaptively adjusting the camera lighting level and distance between a camera and a light reflectance object plane including a reflectance field of view, comprising the steps of: illuminating a reflectance field of view; sensing a desired image field within the reflectance field of view; generating an image signal of said image field; homomorphically filtering said image signal for reducing low frequency components therefrom; generating at least one contrast parameter signal from the filtered image signal, said contrast parameter signal being a function of intensity or luminance of the image field; comparing said at least one contrast parameter signal with a reference signal corresponding to a predetermined contrast level and generating a contrast difference signal; and controlling the light level or the distance between the camera and the light reflectance object plane as a function of said contrast difference signal.
Claim 15
Dependent Claim
89 words
The method of claim 11 wherein said step of homomorphically filtering includes the further steps of: converting the components of said image signal to logarithmic image components, adding said logarithmic image components to from a logarithmic composite image, performing a Fourier transform on said composite image, high pass filtering the transformed composite image, performing an inverse Fourier transform on the filtered composite image, and applying an exponential transfer function to the inverse transformed composite image to provide an output image signal having enhanced reflectance characteristics and attenuated illumination characteristics.
Claim 16
Dependent Claim
151 words
Apparatus for adaptively adjusting the camera lighting level and distance between a camera and a light reflectance object plane including a reflectance field of view, comprising: means for illuminating a reflectance field of view; means for sensing a desired image field within the reflectance field of view; means for generating an image signal of said image field; means for generating a plurality of image parameter signals from the image signal, said contrast parameter signal being a function of intensity of luminance of the image field; means for generating a mean contrast parameter signal from said plurality of contrast parameter signals; means for comparing said mean contrast parameter signal with a reference signal corresponding to a minimum contrast level and generating a contrast difference signal; and means for controlling the light level or the distance between the camera and the light reflectance object place as a function of said contrast difference signal.
Claim 17
Dependent Claim
151 words
Apparatus for adaptively adjusting the camera lighting level and distance between a camera and a light reflectance object plane including a reflectance field of view, comprising: means for illuminating a reflectance field of view; means for sensing a desired image field within the reflectance field of view; means for generating an image signal of said image field; means for generating a plurality of image parameter signals from the image signal, said contrast parameter signal being a function of intensity of luminance of the image field; means for generating a mean contrast parameter signal from said plurality of contrast parameter signals; means for comparing said mean contrast parameter signal with a reference signal corresponding to a minimum contrast level and generating a contrast difference signal; and means for controlling the light level or the distance between the camera and the light reflectance object place as a function of said contrast difference signal.
Claim 18
Dependent Claim
26 words
The apparatus of claim 13 wherein said means for generating a mean contrast parameter signal includes means for reducing low frequency components in said image signal.
Claim 19
Dependent Claim
23 words
The apparatus of claim 14 wherein said means for reducing said low frequency components includes means for reducing homomorphically filtering said image signal.
Claim 20
Dependent Claim
23 words
The apparatus of claim 14 wherein said means for reducing said low frequency components includes means for high pass filtering said image signal.
Claim 21
Dependent Claim
39 words
The apparatus of claim 16 and additionally including, means for low pass filtering said image signal, and means for dividing the high pass filtered image signal by the low pass filtered image signal to generate a normalized image signal.
Claim 22
Dependent Claim
22 words
The apparatus of claim 13 and additionally including means for mounting said camera on a water vehicle nd viewing the sea floor.
Claim 23
Dependent Claim
27 words
The apparatus of claim 18 wherein said water vehicle comprises an underwater vehicle and said image area lies on or in the vicinity of the sea floor.
Claim 24
Dependent Claim
12 words
The apparatus of claim 18 wherein said camera comprises an electronic camera.
Claim 25
Dependent Claim
14 words
The apparatus of claim 20 wherein said electronic camera comprises a CCD electronic camera.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1996-02-09 | 1996-08-10 | 1997-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-02-09 | 2000-08-10 | 2001-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-02-09 | 2004-08-10 | 2005-02-09 | $7700.00 | Window Closed / Lapsed |