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US5949918A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and apparatus for performing image enhancement

Assignee: RPX Corp
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Filing: 1997-08-18
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Granted: 1999-09-07
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Expires: 2017-08-18
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Abstract

Abstract A method and apparatus for processing an image stream to enhance a parameter of the image. The image stream comprises a plurality of picture elements (pixels), each of which include a characteristic related to the image parameter to be enhanced. The pixels are processed according to a controllable function to produce a processed image stream. A statistical distribution of the pixel characteristic of interest is determined, optimized and used to generate control information to modify the operation of the controllable function.

Inventors

  • 👤 Nathaniel Joseph McCaffrey

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 15:08
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/407; H04N1/4072; G; G06; G06T; G06T5/00; G06T5/90; G06T5/92; H04N5/00; H04N5/14; H04N5/20; G06T2207/00; G06T2207/10; G06T2207/10016

Claims Analysis

Total Claims: 22
Claim 1
Independent Claim 130 words
A method for processing an image stream to enhance a parameter of an image, said image comprising a plurality of picture elements (pixels), each of said pixels including a characteristic related to said image parameter, said method comprising the steps of: (a) processing each of said pixels of said image stream according to a controllable function to produce a processed image stream; (b) determining a statistical distribution of said pixel characteristic in said image stream, said statistical distribution representative of said parameter of said image; (c) generating at least one function coefficient for optimizing said determined statistical distribution; and (d) modifying said controllable function using said at least one function coefficient; wherein said controllable function is a remapping function and said at least one function coefficient is a lookup value.
Claim 2
Independent Claim 130 words
A method for processing an image stream to enhance a parameter of an image, said image comprising a plurality of picture elements (pixels), each of said pixels including a characteristic related to said image parameter, said method comprising the steps of: (a) processing each of said pixels of said image stream according to a controllable function to produce a processed image stream; (b) determining a statistical distribution of said pixel characteristic in said image stream, said statistical distribution representative of said parameter of said image; (c) generating at least one function coefficient for optimizing said determined statistical distribution; and (d) modifying said controllable function using said at least one function coefficient; wherein said controllable function is a remapping function and said at least one function coefficient is a lookup value.
Claim 3
Dependent Claim 69 words
The method of claim 1, wherein: said image parameter is a luminance parameter, said pixel characteristic is an intensity level, and one of N possible intensity levels are associated with each of said pixels, and wherein: said step of determining a distribution of said intensity levels comprises the step of counting, for a predetermined number of pixels, the number of pixels having each of said N possible intensity levels.
Claim 4
Dependent Claim 64 words
The method of claim 1 wherein said step of generating one or more function coefficients comprises the steps of: sequentially adding to an accumulator a determined pixel count representative of the number of pixels having an intensity level from a first intensity level to said Nth intensity level; and generating a function coefficient during each sequential addition by dividing the accumulated total by N.
Claim 5
Independent Claim 146 words
A method for processing an image stream to enhance a parameter of an image, said image comprising a plurality of picture elements (pixels), each of said pixels including a characteristic related to said image parameter, said method comprising the steps of: (a) processing each of said pixels of said image stream according to a controllable function to produce a processed image stream; (b) determining a statistical distribution of said pixel characteristic in said image stream, said statistical distribution representative of said parameter of said image; (c) generating at least one function coefficient for optimizing said determined statistical distribution; and (d) modifying said controllable function using said at least one function coefficient; wherein said step of determining further comprises the steps of: identifying pixels within said image that represent motion within the image; and emphasizing the statistical significance of said pixel characteristics associated with said identified pixels.
Claim 6
Independent Claim 146 words
A method for processing an image stream to enhance a parameter of an image, said image comprising a plurality of picture elements (pixels), each of said pixels including a characteristic related to said image parameter, said method comprising the steps of: (a) processing each of said pixels of said image stream according to a controllable function to produce a processed image stream; (b) determining a statistical distribution of said pixel characteristic in said image stream, said statistical distribution representative of said parameter of said image; (c) generating at least one function coefficient for optimizing said determined statistical distribution; and (d) modifying said controllable function using said at least one function coefficient; wherein said step of determining further comprises the steps of: identifying pixels within said image that represent motion within the image; and emphasizing the statistical significance of said pixel characteristics associated with said identified pixels.
Claim 7
Independent Claim 179 words
A method for processing an image stream to enhance a parameter of an image, said image comprising a plurality of picture elements (pixels), each of said pixels including a characteristic related to said image parameter, said method comprising the steps of: (a) processing each of said pixels of said image stream according to a controllable function to produce a processed image stream; (b) determining a statistical distribution of said pixel characteristic in said image stream, said statistical distribution representative of said parameter of said image; (c) generating at least one function coefficient for optimizing said determined statistical distribution; and (d) modifying said controllable function using said at least one function coefficient; wherein said image parameter is a color parameter, said pixel characteristic is a color saturation level, and one of N possible color saturation levels are associated with each of said pixels, and wherein: said step of determining a distribution of said color saturation levels comprises the step of counting, for a predetermined number of pixels, the number of pixels having each of said N possible color saturation levels.
Claim 8
Independent Claim 179 words
A method for processing an image stream to enhance a parameter of an image, said image comprising a plurality of picture elements (pixels), each of said pixels including a characteristic related to said image parameter, said method comprising the steps of: (a) processing each of said pixels of said image stream according to a controllable function to produce a processed image stream; (b) determining a statistical distribution of said pixel characteristic in said image stream, said statistical distribution representative of said parameter of said image; (c) generating at least one function coefficient for optimizing said determined statistical distribution; and (d) modifying said controllable function using said at least one function coefficient; wherein said image parameter is a color parameter, said pixel characteristic is a color saturation level, and one of N possible color saturation levels are associated with each of said pixels, and wherein: said step of determining a distribution of said color saturation levels comprises the step of counting, for a predetermined number of pixels, the number of pixels having each of said N possible color saturation levels.
Claim 9
Dependent Claim 67 words
The method of claim 5 wherein said step of generating one or more function coefficients comprises the steps of: sequentially adding to an accumulator a determined pixel count representative of the number of pixels having an color saturation level from a first color saturation level to said Nth color saturation level; and generating a function coefficient during each sequential addition by dividing the accumulated total by N.
Claim 10
Dependent Claim 24 words
The method of claim 5, wherein said controllable function is a remapping function and said at least one function coefficient is a lookup value.
Claim 11
Dependent Claim 40 words
The method of claim 5, wherein said step of determining further comprises the steps of: identifying pixels within said image that represent motion within the image; and emphasizing the statistical significance of said pixel characteristics associated with said identified pixels.
Claim 12
Dependent Claim 204 words
Apparatus processing an image stream to enhance a parameter of an image, said image comprising a plurality of picture elements (pixels), each of said pixels including a characteristic related to said image parameter, said apparatus comprising: a pixel processor, receiving said image stream at an input and producing a processed image stream at an output, said pixel processor processing each received pixel of said image stream according to a controllable function; a controller, coupled to said pixel processor and receiving said digital video signal at an input, said controller determining a statistical distribution of said pixel characteristic in said image stream and generating at least one function coefficient for optimizing said determined statistical distribution; a motion detector, receiving said image stream at an input and producing an indicium of detected motion at an output, said motion detector identifying pixels within said image stream that represent motion within the image; and a priority adjuster, coupled to said motion detector, for emphasizing the statistical significance of said pixel characteristics associated with said pixels within said image stream that represent motion within the image; said pixel processor, in response to a control signal from said controller, modifying said controllable function using said at least one function coefficient.
Claim 13
Dependent Claim 204 words
Apparatus processing an image stream to enhance a parameter of an image, said image comprising a plurality of picture elements (pixels), each of said pixels including a characteristic related to said image parameter, said apparatus comprising: a pixel processor, receiving said image stream at an input and producing a processed image stream at an output, said pixel processor processing each received pixel of said image stream according to a controllable function; a controller, coupled to said pixel processor and receiving said digital video signal at an input, said controller determining a statistical distribution of said pixel characteristic in said image stream and generating at least one function coefficient for optimizing said determined statistical distribution; a motion detector, receiving said image stream at an input and producing an indicium of detected motion at an output, said motion detector identifying pixels within said image stream that represent motion within the image; and a priority adjuster, coupled to said motion detector, for emphasizing the statistical significance of said pixel characteristics associated with said pixels within said image stream that represent motion within the image; said pixel processor, in response to a control signal from said controller, modifying said controllable function using said at least one function coefficient.
Claim 14
Dependent Claim 88 words
The apparatus of claim 9, wherein said image parameter and said pixel characteristic comprises either a luminance parameter and a respective intensity level, or a color parameter and a respective color saturation level; one of N possible intensity levels or color saturation levels are associated with each of said pixels, and said controller determines said distribution of said intensity levels or color saturation levels by counting, for a predetermined number of pixels, the number of pixels having each of said N possible intensity levels or color saturation levels.
Claim 15
Dependent Claim 65 words
The apparatus of claim 9, wherein said controller generates said one or more function coefficients by sequentially adding to an accumulator a determined pixel count representative of the number of pixels having a color saturation level from a first color saturation level to said Nth color saturation level, said controller generating a function coefficient during each sequential addition by dividing the accumulated total by N.
Claim 16
Dependent Claim 157 words
Apparatus processing an image stream to enhance a parameter of an image, said image comprising a plurality of picture elements (pixels), each of said pixels including a characteristic related to said image parameter, said apparatus comprising: a pixel processor, receiving said image stream at an input and producing a processed image stream at an output, said pixel processor processing each received pixel of said image stream according to a controllable function; and a controller, coupled to said pixel processor and receiving said digital video signal at an input, said controller determining a statistical distribution of said pixel characteristic in said image stream and generating at least one function coefficient for optimizing said determined statistical distribution; said pixel processor, in response to a control signal from said controller, modifying said controllable function using said at least one function coefficient; wherein said controllable function is a remapping function and said at least one function coefficient is a lookup value.
Claim 17
Dependent Claim 157 words
Apparatus processing an image stream to enhance a parameter of an image, said image comprising a plurality of picture elements (pixels), each of said pixels including a characteristic related to said image parameter, said apparatus comprising: a pixel processor, receiving said image stream at an input and producing a processed image stream at an output, said pixel processor processing each received pixel of said image stream according to a controllable function; and a controller, coupled to said pixel processor and receiving said digital video signal at an input, said controller determining a statistical distribution of said pixel characteristic in said image stream and generating at least one function coefficient for optimizing said determined statistical distribution; said pixel processor, in response to a control signal from said controller, modifying said controllable function using said at least one function coefficient; wherein said controllable function is a remapping function and said at least one function coefficient is a lookup value.
Claim 18
Dependent Claim 74 words
The apparatus of claim 12, further comprising: a motion detector, receiving said image stream at an input and producing an indicium of detected motion at an output, said motion detector identifying pixels within said image stream that represent motion within the image; and a priority adjuster, coupled to said motion detector, for emphasizing the statistical significance of said pixel characteristics associated with said pixels within said image stream that represent motion within the image.
Claim 19
Dependent Claim 65 words
The apparatus of claim 12, wherein said controller generates said one or more function coefficients by sequentially adding to an accumulator a determined pixel count representative of the number of pixels having a color saturation level from a first color saturation level to said Nth color saturation level, said controller generating a function coefficient during each sequential addition by dividing the accumulated total by N.
Claim 20
Dependent Claim 230 words
Apparatus for contrast-enhancing a digital video signal, said digital video signal comprising a sequence of picture elements (pixels), each of said pixels having an associated intensity level, said apparatus comprising: a pixel processor, receiving said digital video signal at an input, and in response to each received pixel providing at an output a pixel having an intensity level derived from a lookup table, said lookup table having one element representing each of N possible intensity levels; and a controller, coupled to said pixel processor and receiving said digital video signal at an input, said controller statistically determining a luminance profile of said digital video signal, adjusting said statistically determined luminance profile to provide an enhanced contrast luminance profile, and coupling said enhanced contrast luminance profile to said pixel processor; said pixel processor selectively adjusting said lookup table elements in response to said enhanced contrast luminance profile; said controller statistically determining said luminance profile of said digital video signal by counting the number of M pixels having each of said N possible intensity levels; and said controller generates said one or more function coefficients by sequentially adding to an accumulator a determined pixel count representative of the number of pixels having an intensity level from a first intensity level to said Nth intensity level, said controller generating a function coefficient during each sequential addition by dividing the accumulated total by N.
Claim 21
Dependent Claim 230 words
Apparatus for contrast-enhancing a digital video signal, said digital video signal comprising a sequence of picture elements (pixels), each of said pixels having an associated intensity level, said apparatus comprising: a pixel processor, receiving said digital video signal at an input, and in response to each received pixel providing at an output a pixel having an intensity level derived from a lookup table, said lookup table having one element representing each of N possible intensity levels; and a controller, coupled to said pixel processor and receiving said digital video signal at an input, said controller statistically determining a luminance profile of said digital video signal, adjusting said statistically determined luminance profile to provide an enhanced contrast luminance profile, and coupling said enhanced contrast luminance profile to said pixel processor; said pixel processor selectively adjusting said lookup table elements in response to said enhanced contrast luminance profile; said controller statistically determining said luminance profile of said digital video signal by counting the number of M pixels having each of said N possible intensity levels; and said controller generates said one or more function coefficients by sequentially adding to an accumulator a determined pixel count representative of the number of pixels having an intensity level from a first intensity level to said Nth intensity level, said controller generating a function coefficient during each sequential addition by dividing the accumulated total by N.
Claim 22
Dependent Claim 42 words
The apparatus of claim 15, further comprising: a motion detector, coupled to said controller, for determining which pixels represent motion in the image; said pixel processor emphasizing the statistical significance of said pixel characteristics associated with pixels representing motion in the image.

References Cited (Backward Citations)

US4755954A Cited
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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) 2002-09-06 2003-03-08 2003-09-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2006-09-06 2007-03-08 2007-09-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2010-09-06 2011-03-08 2011-09-07 $7700.00 Window Closed / Lapsed

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