Patent US6513124B1 successfully refreshed from Google Patents.
Patent US5021880A successfully refreshed from Google Patents.
US5021880A
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US
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Digital video signal compression
Assignee: Nortel Networks Ltd
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Filing: 1990-06-13
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Granted: 1991-06-04
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Expires: 2010-06-13
Abstract
Abstract Digital samples of an HDTV video signal are compressed by determining groups each of three successive samples in the video signal lines, the groups in adjacent lines being offset from one another, and transmitting only a first sample in each group. Each of the second and third samples in each group is compared with magnitudes averaged from three adjacent, transmitted, first samples, one in each of the previous, same, and following video signal lines, to determine a closest match. A 2-bit code representing this closest match is transmitted for each of these second and third samples in each group. The groups, and hence the first samples, are offset from one another in adjacent video signal lines, and the sampling frequency is desirably an odd multiple of half the video signal line frequency to offset the sampled pixels in adjacent video signal lines. The invention provides a high compression ratio, which can be further increased by DPCM encoding of the successive first samples.
Inventors
- 👤 Alan F. Graves
- 👤 Raymond L. Greenfield
- 👤 Barry B. Hagglund
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:59
CPC Classifications
H; H04; H04N; H04N19/00; H04N19/10; H04N19/169; H04N19/186; H04N11/00; H04N11/04; H04N11/042; H04N19/50; H04N19/59; H04N7/00; H04N7/015; H04N7/0152; H04N7/12; H04N7/122; H04N7/125
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
131 words
A method of providing a compressed digital video signal comprising the steps of: providing digital video signal samples at a sampling frequency, the samples representing respective pixels in lines of a video signal; determining groups each of three successive samples in each video signal line, the groups in adjacent lines being offset from one another; representing a first sample in each group by a first number of bits; comparing each of a second and a third sample in each group with magnitudes derived in a predetermined manner from a plurality of adjacent first samples to determine a closest match; and representing each of the second and third samples in each group by a second number of bits indicative of the closest match, the second number being less than the first number.
Claim 2
Independent Claim
131 words
A method of providing a compressed digital video signal comprising the steps of: providing digital video signal samples at a sampling frequency, the samples representing respective pixels in lines of a video signal; determining groups each of three successive samples in each video signal line, the groups in adjacent lines being offset from one another; representing a first sample in each group by a first number of bits; comparing each of a second and a third sample in each group with magnitudes derived in a predetermined manner from a plurality of adjacent first samples to determine a closest match; and representing each of the second and third samples in each group by a second number of bits indicative of the closest match, the second number being less than the first number.
Claim 3
Dependent Claim
30 words
A method as claimed in claim 1 wherein the plurality of adjacent first samples comprise an adjacent first sample in each of the previous, same, and following video signal lines.
Claim 4
Dependent Claim
40 words
A method as claimed in claim 2 wherein the magnitudes with which each second or third sample is compared include an average of at least two of the adjacent first samples in the previous, same, and following video signals lines.
Claim 5
Dependent Claim
42 words
A method as claimed in claim 2 wherein the magnitudes with which each second or third sample is compared comprise an average of each combination of two of the three adjacent first samples in the previous, same, and following video signal lines.
Claim 6
Dependent Claim
39 words
A method as claimed in claim 4 wherein the magnitudes with which each second or third sample is compared further comprise a weighted average of the three adjacent first samples in the previous, same, and following video signal lines.
Claim 7
Dependent Claim
13 words
A method as claimed in claim 5 wherein the second number is two.
Claim 8
Dependent Claim
13 words
A method as claimed in claim 1 wherein the second number is two.
Claim 9
Dependent Claim
52 words
A method as claimed in claim 6 wherein the sampling frequency is an odd multiple of half the video signal line frequency, whereby the samples represent pixels which are offset from one another in adjacent video signal lines and the groups in adjacent lines are offset from one another by 1.5 samples.
Claim 10
Dependent Claim
38 words
A method as claimed in claim 1 wherein the sampling frequency is an odd multiple of half the video signal line frequency, whereby the samples represent pixels which are offset from one another in adjacent video signal lines.
Claim 11
Dependent Claim
21 words
A method as claimed in claim 9 wherein the groups in adjacent lines are offset from one another by 1.5 samples.
Claim 12
Dependent Claim
29 words
A method as claimed in claim 8 wherein the step of representing the first samples each by a first number of bits comprises differentially encoding the successive first samples.
Claim 13
Dependent Claim
29 words
A method as claimed in claim 1 wherein the step of representing the first samples each by a first number of bits comprises differentially encoding the successive first samples.
Claim 14
Dependent Claim
29 words
A method as claimed in claim 3 wherein the step of representing the first samples each by a first number of bits comprises differentially encoding the successive first samples.
Claim 15
Dependent Claim
124 words
Apparatus for compressing digital video signal samples representing respective pixels in lines of a video signal, comprising: timing means for determining groups each of three successive samples in each video signal line, the groups in adjacent lines being offset from one another; means for representing a first sample in each group by a first number of bits; means for comparing each of a second and a third sample in each group with magnitudes derived in a predetermined manner from a plurality of adjacent first samples to determine a closest match; and means for representing each of the second and third samples in each group by a second number of bits indicative of the closest match, the second number being less than the first number.
Claim 16
Dependent Claim
124 words
Apparatus for compressing digital video signal samples representing respective pixels in lines of a video signal, comprising: timing means for determining groups each of three successive samples in each video signal line, the groups in adjacent lines being offset from one another; means for representing a first sample in each group by a first number of bits; means for comparing each of a second and a third sample in each group with magnitudes derived in a predetermined manner from a plurality of adjacent first samples to determine a closest match; and means for representing each of the second and third samples in each group by a second number of bits indicative of the closest match, the second number being less than the first number.
Claim 17
Dependent Claim
25 words
Apparatus as claimed in claim 14 wherein the means for representing the first samples each by a first number of bits comprises a DPCM encoder.
Claim 18
Independent Claim
186 words
A method of providing a compressed digital video signal comprising the steps of: providing digital video signal samples at a sampling frequency, the samples representing respective pixels in lines of a video signal; in each video signal line, determining consecutive groups of samples each comprising three consecutive samples in the video signal line, the groups of samples in each video signal line being horizontally offset from the groups of samples in the immediately preceding video signal line and the immediately following video signal line; representing a first sample in each group of samples by a first number of bits; comparing each of a second and third sample in each group of samples with a plurality of magnitudes derived from an adjacent first sample in the same video signal line, an adjacent first sample in the immediately preceding video signal line, and an adjacent first sample in the immediately following video signal line; and representing each of the second and third samples in each group of samples by a second number of bits indicative of the closest comparison, the second number being less than the first number.
Claim 19
Independent Claim
186 words
A method of providing a compressed digital video signal comprising the steps of: providing digital video signal samples at a sampling frequency, the samples representing respective pixels in lines of a video signal; in each video signal line, determining consecutive groups of samples each comprising three consecutive samples in the video signal line, the groups of samples in each video signal line being horizontally offset from the groups of samples in the immediately preceding video signal line and the immediately following video signal line; representing a first sample in each group of samples by a first number of bits; comparing each of a second and third sample in each group of samples with a plurality of magnitudes derived from an adjacent first sample in the same video signal line, an adjacent first sample in the immediately preceding video signal line, and an adjacent first sample in the immediately following video signal line; and representing each of the second and third samples in each group of samples by a second number of bits indicative of the closest comparison, the second number being less than the first number.
Claim 20
Dependent Claim
34 words
A method as claimed in claim 16 wherein the step of representing the first samples each by a first number of bits comprises differentially encoding the first samples of the consecutive groups of samples.
Claim 21
Dependent Claim
40 words
A method as claimed in claim 16 wherein the plurality of magnitudes comprise a plurality of averages of said adjacent first samples in the same, immediately preceding, and immediately following video signal lines, and wherein the second number is 2.
Claim 22
Dependent Claim
57 words
A method as claimed in claim 18 wherein the sampling frequency is an odd multiple of half the video signal line frequency, whereby the samples represent pixels which are offset from one another in adjacent video signal lines, and the groups of samples in adjacent video signal lines are horizontally offset from one another by 1.5 samples.
Claim 23
Dependent Claim
34 words
A method as claimed in claim 19 wherein the step of representing the first samples each by a first number of bits comprises differentially encoding the first samples of the consecutive groups of samples.
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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) | 1994-06-03 | 1994-12-03 | 1995-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-03 | 1998-12-03 | 1999-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-03 | 2002-12-03 | 2003-06-04 | $7700.00 | Window Closed / Lapsed |