EP0574724A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Adaptive coding level control for video compression systems
Assignee: Arris Technology Inc
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Filing: 1993-05-20
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Granted: —
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Expires: 2013-05-20
Abstract
Abstract An apparatus and method for adaptively compressing blocks of video image data provide a local coding level (34) for use in compressing successive blocks of video image data. Each block is preliminarily compressed (30) using a global coding level. The preliminarily compressed data is processed (32) to provide a measure of the randomness of an image area represented by the block of video image data. A local coding level is generated (34) based on the randomness measure. The video image data is then compressed (36) using the local coding level to provide compressed data for transmission. One or more intermediate compression stages (16, 18) can be provided, each generating an intermediate coding level (ICL), to better refine the randomness measure for use in generating the local coding level.
Inventors
- 👤 Woo H. Paik
- 👤 Edward A. Krause
- 👤 Vincent Liu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 03:29
CPC Classifications
H; H04; H04N; H04N19/00; H04N19/10; H04N19/102; H04N19/103; H04N19/124; H04N19/134; H04N19/136; H04N19/14; H04N19/146; H04N19/15; H04N19/169; H04N19/17; H04N19/176; H04N19/189; H04N19/192; H04N19/50; H04N19/60; H04N19/61; H04N19/30; H04N19/39
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
81 words
Apparatus for adaptively compressing blocks of video image data according to a local coding level, comprising: an initial compression stage including: means for compressing data in a data block based on a global coding level to provide a compressed data block containing a number of bits, and means responsive to said number of bits for providing a local coding level; and a final compression stage including: means for compressing the data in said data block based on said local coding level.
Claim 2
Dependent Claim
34 words
Apparatus in accordance with claim 1 wherein: said local coding level providing means comprise look up table means responsive to a count based on said number of bits for outputting said local coding level.
Claim 3
Dependent Claim
39 words
Apparatus in accordance with claim 2 wherein: said look up table means receive the difference between said number of bits and a reference count as a first address input and said global coding level as a second address input.
Claim 4
Dependent Claim
137 words
Apparatus for adaptively compressing blocks of video image data according to a local coding level, comprising: an initial compression stage including: means for compressing data in a data block based on a global coding level to provide a compressed data block containing a number of bits, and means for providing an intermediate coding level based on said number of bits; an intermediate compression stage following said initial compression stage including: intermediate compressing means for compressing the data in said data block based on an intermediate coding level from a preceding stage, and means for providing a local coding level based on the number of bits produced by said intermediate compressing means; and a final compression stage following said intermediate compression stage including: means for compressing the data in said data block based on said local coding level.
Claim 5
Dependent Claim
39 words
Apparatus in accordance with claim 4 wherein: the coding level providing means for each stage comprise look up table means, responsive to the number of bits produced by the compressing means for that stage, for outputting a coding level.
Claim 6
Dependent Claim
29 words
Apparatus in accordance with claim 5 wherein: said look up table means are also responsive to the coding level provided by a preceding stage for outputting said coding levels.
Claim 7
Dependent Claim
35 words
Apparatus in accordance with claim 4 wherein: the coding level providing means for each stage comprise look up table means, responsive to a coding level provided by a preceding stage, for outputting a coding level.
Claim 8
Dependent Claim
40 words
Apparatus in accordance with one of claims 4 to 7 wherein each coding level providing means provides its respective coding level based on a difference between a reference count and the number of bits produced by the associated compressing means.
Claim 9
Independent Claim
70 words
A method for adaptively compressing blocks of video image data according to a local coding level, comprising the steps of: preliminarily compressing video image data; processing the preliminarily compressed video image data to provide a measure of the randomness of an image area represented by the video image data; generating a local coding level based on said measure; and compressing said video image data based on said local coding level.
Claim 10
Dependent Claim
25 words
A method in accordance with claim 9 wherein: said preliminary compressing step compresses a block of video image data based on a global coding level.
Claim 11
Dependent Claim
113 words
A method in accordance with claim 9 wherein said preliminary compressing and processing steps comprise the steps of: first compressing a block of video image data based on a global coding level to provide first compressed data; processing said first compressed data to provide a first measure of the randomness of said image area; generating an intermediate coding level based on said first measure; next compressing said block of video image data based on said intermediate coding level to provide second compressed data; and processing said second compressed data to provide a second measure of the randomness of said image area; wherein said local coding level is generated based on said second measure.
Claim 12
Dependent Claim
32 words
A method in accordance with claim 11 comprising additional compressing and processing steps after said first compressing step to provide at least one additional measure of the randomness of said image area.
Claim 13
Dependent Claim
28 words
A method in accordance with claim 9 wherein said processing step provides said measure by determining the amount of data that is generated by said preliminary compressing step.
Claim 14
Independent Claim
70 words
A method for adaptively adjusting a signal coding level throughout an image area represented by an encoded video signal comprising the steps of: determining the randomness of a plurality of different regions that reside in said image area; and providing a lower quality coding level for use in compressing regions that are more random to enable the use of a higher quality coding level in regions that are less random.
Claim 15
Dependent Claim
49 words
A method in accordance with claim 14 wherein said determining step comprises the steps of: compressing data from said regions; and determining the amount of compressed data generated for each region; wherein the amount of data generated for a region is a measure of the randomness of that region.
References Cited (Backward Citations)
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