US5329311A
Expired / Lapsed
US
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System for determining noise content of a video signal in the disclosure
Assignee: Zarbana Digital Fund LLC
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Filing: 1993-05-11
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Granted: 1994-07-12
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Expires: 2013-05-11
Abstract
Abstract A method of determining the noise content of a video signal by digitizing a frame based on the video signal to provide a digitized signal which is then filtered via a high pass filter. The filtered image is then divided into a plurality of subimages and the noise signal in each of the subimages is determined from a selected number of subimages having the lowest noise signal are further processed to determine the average noise in the selected subimages and the signal-to-noise ratio determined. The carrier-to-noise ratio may also be determined if desired.
Inventors
- 👤 Rabab K. Ward
- 👤 Qin Zhang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:01
CPC Classifications
H; H04; H04N; H04N17/00
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
94 words
A method of determining the noise content of a video signal comprising digitizing a frame of said video signal to provide a digitized signal, subjecting said digitized signal to a high pass filter to remove the majority of said signal representing picture information in said frame and provide a filtered image, subdividing said filtered image into a plurality of subimages, determining noise signal in each of said subimages, selecting a selected number of subimages having the lowest noise signals, determining the signal-to-noise ratio based on the average noise in said selected number of subimages.
Claim 2
Independent Claim
94 words
A method of determining the noise content of a video signal comprising digitizing a frame of said video signal to provide a digitized signal, subjecting said digitized signal to a high pass filter to remove the majority of said signal representing picture information in said frame and provide a filtered image, subdividing said filtered image into a plurality of subimages, determining noise signal in each of said subimages, selecting a selected number of subimages having the lowest noise signals, determining the signal-to-noise ratio based on the average noise in said selected number of subimages.
Claim 3
Dependent Claim
19 words
A method as defined in claim 1 wherein said signal-to-noise ratio is further used to determine the carrier-to-noise ratio.
Claim 4
Dependent Claim
20 words
A method as defined in claim 1 wherein said filtering comprises convolving said digitized frame with the following filter: ##EQU14##
Claim 5
Dependent Claim
26 words
A method as defined in claim 3 wherein said high pass filter in the spectrum domain will be as follows: ##EQU15## I,J=0,1,2 . . . ,N-1
Claim 6
Dependent Claim
50 words
A method as defined in claim 4 wherein said noise will have an average value calculated (based on each sub image being 32×32 pixels) in accordance with the following equation: ##EQU16## wherein y is the average noise pixel value and y ij is the pixel value after high pass filtering.
Claim 7
Dependent Claim
25 words
A method as defined in claim 5 wherein the signal-to-noise ratio is calculated using the following model: ##EQU17## wherein √x 2 is defined as ##EQU18##
Claim 8
Dependent Claim
24 words
A method as defined in claim 6 wherein a carrier-to-noise ratio is determined in accordance with ##EQU19## wherein √x 2 is defined as ##EQU20##
Claim 9
Dependent Claim
20 words
A method as defined in claim 6 wherein a carrier-to-noise ratio is determined in accordance with the formula CNR=SNR+4.1 dB
Claim 10
Dependent Claim
16 words
A method as defined in claim 1 wherein said selected number is between two and five.
Claim 11
Dependent Claim
16 words
A method as defined in claim 3 wherein said selected number is between two and five.
Claim 12
Dependent Claim
16 words
A method as defined in claim 4 wherein said selected number is between two and five.
Claim 13
Dependent Claim
16 words
A method as defined in claim 5 wherein said selected number is between two and five.
Claim 14
Dependent Claim
16 words
A method as defined in claim 6 wherein said selected number is between two and five.
Claim 15
Dependent Claim
16 words
A method as defined in claim 7 wherein said selected number is between two and five.
Claim 16
Dependent Claim
16 words
A method as defined in claim 8 wherein said selected number is between two and five.
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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) | 1997-07-11 | 1998-01-10 | 1998-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-07-11 | 2002-01-10 | 2002-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-07-11 | 2006-01-10 | 2006-07-12 | $7700.00 | Window Closed / Lapsed |