Adaptive coding - Revision history

Mrfoogles: Add citation

2025-03-06T04:30:40Z

Add citation

← Previous revision		Revision as of 04:30, 6 March 2025
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	{{~~unreferenced~~\|date=~~June~~ ~~2009\|bot=yes~~}}		{{More citations needed\|date=March 2025}}

	'''Adaptive coding''' refers to variants of [[entropy encoding]] methods of [[lossless data compression]]. They are particularly suited to [[streaming data]], as they adapt to localized changes in the characteristics of the data, and don't require a first pass over the data to calculate a probability model. The cost paid for these advantages is that the encoder and decoder must be more complex to keep their states synchronized, and more computational power is needed to keep adapting the encoder/decoder state.		'''Adaptive coding''' refers to variants of [[entropy encoding]] methods of [[lossless data compression]].{{Citation needed\|date=March 2025}} They are particularly suited to [[streaming data]], as they adapt to localized changes in the characteristics of the data,{{Citation needed\|date=March 2025}} and don't require a first pass over the data to calculate a probability model.<ref name=":0">{{Cite book \|last=Williams \|first=Ross N. \|url=https://www.google.com/books/edition/Adaptive_Data_Compression/lBY6CcXU59EC?hl=en&gbpv=1&pg=PR11&printsec=frontcover \|title=Adaptive Data Compression \|date=1991 \|publisher=Springer Science & Business Media \|isbn=978-0-7923-9085-5 \|language=en}}</ref> The cost paid for these advantages is that the encoder and decoder must be more complex to keep their states synchronized, and more computational power is needed to keep adapting the encoder/decoder state.

	Almost all [[data compression]] methods involve the use of a ''model'', a prediction of the composition of the data. When the data matches the prediction made by the model, the encoder can usually transmit the content of the data at a lower information cost, by making reference to the model.		Almost all [[data compression]] methods involve the use of a ''model'', a prediction of the composition of the data. When the data matches the prediction made by the model, the encoder can usually transmit the content of the data at a lower information cost, by making reference to the model.
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	==Adaptive method==		==Adaptive method==
			The operating method of adaptive encoding algorithms is as follows:<ref name=":0" />

	===Encoder===		===Encoder===

XOR'easter: Undid revision 1261657597 by JulioISalazarG (talk): the cited article is about macaque brains, not run-length encoding or JPEG compression

2024-12-08T01:42:33Z

Undid revision 1261657597 by JulioISalazarG (talk): the cited article is about macaque brains, not run-length encoding or JPEG compression

← Previous revision		Revision as of 01:42, 8 December 2024
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	which are hardly comparable to compression techniques typically called ''adaptive''.		which are hardly comparable to compression techniques typically called ''adaptive''.
	[[Run-length encoding]] and the typical [[JPEG]] compression with run length encoding and predefined Huffman codes do not transmit a model.		[[Run-length encoding]] and the typical [[JPEG]] compression with run length encoding and predefined Huffman codes do not transmit a model.
	A lot of other methods adapt their model to the current file and need to transmit it in addition to the encoded data, because both the encoder and the decoder need to use the model.<ref>{{Cite journal \|author1=Gutnisky, D. \|author2=Dragoi, V. \|year=2008 \|title=Adaptive coding of visual information in neural populations \|journal=Nature \|volume=452 \|pages=220–224 \|doi=10.1038/nature06563}}</ref>		A lot of other methods adapt their model to the current file and need to transmit it in addition to the encoded data, because both the encoder and the decoder need to use the model.

	In adaptive coding, the encoder and decoder are instead equipped with a predefined meta-model about how they will alter their models in response to the actual content of the data, and otherwise start with a blank slate, meaning that no initial model needs to be transmitted. As the data is transmitted, both encoder and decoder adapt their models, so that unless the character of the data changes radically, the model becomes better-adapted to the data it is handling and compresses it more efficiently approaching the efficiency of the static coding.		In adaptive coding, the encoder and decoder are instead equipped with a predefined meta-model about how they will alter their models in response to the actual content of the data, and otherwise start with a blank slate, meaning that no initial model needs to be transmitted. As the data is transmitted, both encoder and decoder adapt their models, so that unless the character of the data changes radically, the model becomes better-adapted to the data it is handling and compresses it more efficiently approaching the efficiency of the static coding.

DrBorgI: Adding prestigious sources to back information.

2024-12-07T06:54:42Z

Adding prestigious sources to back information.

← Previous revision		Revision as of 06:54, 7 December 2024
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	which are hardly comparable to compression techniques typically called ''adaptive''.		which are hardly comparable to compression techniques typically called ''adaptive''.
	[[Run-length encoding]] and the typical [[JPEG]] compression with run length encoding and predefined Huffman codes do not transmit a model.		[[Run-length encoding]] and the typical [[JPEG]] compression with run length encoding and predefined Huffman codes do not transmit a model.
	A lot of other methods adapt their model to the current file and need to transmit it in addition to the encoded data, because both the encoder and the decoder need to use the model.		A lot of other methods adapt their model to the current file and need to transmit it in addition to the encoded data, because both the encoder and the decoder need to use the model.<ref>{{Cite journal \|author1=Gutnisky, D. \|author2=Dragoi, V. \|year=2008 \|title=Adaptive coding of visual information in neural populations \|journal=Nature \|volume=452 \|pages=220–224 \|doi=10.1038/nature06563}}</ref>

	In adaptive coding, the encoder and decoder are instead equipped with a predefined meta-model about how they will alter their models in response to the actual content of the data, and otherwise start with a blank slate, meaning that no initial model needs to be transmitted. As the data is transmitted, both encoder and decoder adapt their models, so that unless the character of the data changes radically, the model becomes better-adapted to the data it is handling and compresses it more efficiently approaching the efficiency of the static coding.		In adaptive coding, the encoder and decoder are instead equipped with a predefined meta-model about how they will alter their models in response to the actual content of the data, and otherwise start with a blank slate, meaning that no initial model needs to be transmitted. As the data is transmitted, both encoder and decoder adapt their models, so that unless the character of the data changes radically, the model becomes better-adapted to the data it is handling and compresses it more efficiently approaching the efficiency of the static coding.

IznoRepeat: /* References */ add WP:TEMPLATECAT to remove from template; genfixes

2024-12-05T23:50:46Z

References: add WP:TEMPLATECAT to remove from template; genfixes

← Previous revision		Revision as of 23:50, 5 December 2024
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	[[Category:Lossless compression algorithms]]		[[Category:Lossless compression algorithms]]
			[[Category:Data compression]]

Boleyn: /* Cassini Lossless Compression */

2024-05-11T14:36:18Z

Cassini Lossless Compression

← Previous revision		Revision as of 14:36, 11 May 2024
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	* Each compressed image can be reconstructed on the ground with no loss to the information content of the image, provided the image entropy does not exceed the threshold where 2:1 compression is reached.		* Each compressed image can be reconstructed on the ground with no loss to the information content of the image, provided the image entropy does not exceed the threshold where 2:1 compression is reached.
	* Due to camera problems and the need to reduce file size, there is a slight modification to the image coding scheme so that each compressed line is effectively bandwidth limited on the number of bits available to encode it.		* Due to camera problems and the need to reduce file size, there is a slight modification to the image coding scheme so that each compressed line is effectively bandwidth limited on the number of bits available to encode it.

			==References==
			{{Reflist}}

	{{Compression Methods}}		{{Compression Methods}}

95.24.161.69 at 20:57, 28 March 2024

2024-03-28T20:57:05Z

← Previous revision		Revision as of 20:57, 28 March 2024
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	* Due to camera problems and the need to reduce file size, there is a slight modification to the image coding scheme so that each compressed line is effectively bandwidth limited on the number of bits available to encode it.		* Due to camera problems and the need to reduce file size, there is a slight modification to the image coding scheme so that each compressed line is effectively bandwidth limited on the number of bits available to encode it.

			{{Compression Methods}}
	{{CCSDS}}		{{CCSDS}}

PointyOintment: /* Examples */ decapitalized and linked Dione

2019-12-29T06:28:59Z

Examples: decapitalized and linked Dione

← Previous revision		Revision as of 06:28, 29 December 2019
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	Adaptive image coding was used by the [[Cassini-Huygens]] craft to relay images from [[Saturn]]. Only about 5% of the images show any visual signs of damage. As the spacecraft has an error correcting [[Solid-state drive\|Flash drive]] and long timeframes between image taking events, damaged images like this can be present. It is assumed that the number of damaged, but unrecoverable images from the Cassini mission is about 0.01% or less.{{Update inline\|date=December 2019\|reason=How many of the images were actually damaged, now that the mission has ended?}}		Adaptive image coding was used by the [[Cassini-Huygens]] craft to relay images from [[Saturn]]. Only about 5% of the images show any visual signs of damage. As the spacecraft has an error correcting [[Solid-state drive\|Flash drive]] and long timeframes between image taking events, damaged images like this can be present. It is assumed that the number of damaged, but unrecoverable images from the Cassini mission is about 0.01% or less.{{Update inline\|date=December 2019\|reason=How many of the images were actually damaged, now that the mission has ended?}}

	[[Image:Damaged N00153918.jpg\|thumb\|center\|450px\|The Cassini camera was pointing toward ~~DIONE~~ at a distance of approximately 548,210 kilometers. The image was taken using the CL1 and CL2 filters on May 17, 2010.]]		[[Image:Damaged N00153918.jpg\|thumb\|center\|450px\|The Cassini camera was pointing toward [[Dione (moon)\|Dione]] at a distance of approximately 548,210 kilometers. The image was taken using the CL1 and CL2 filters on May 17, 2010.\|alt=]]

	=== Cassini Lossless Compression ===		=== Cassini Lossless Compression ===

PointyOintment: /* Examples */ partly updated—Cassini mission has ended

2019-12-29T06:28:21Z

Examples: partly updated—Cassini mission has ended

← Previous revision		Revision as of 06:28, 29 December 2019
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	== Examples ==		== Examples ==
	Adaptive image coding ~~is currently being~~ used by the [[Cassini-Huygens]] craft to relay images from [[Saturn]]. Only about 5% of the images show any visual signs of damage. As the spacecraft has an error correcting [[Solid-state drive\|Flash drive]] and long timeframes between image taking events, damaged images like this can be present. It is assumed that the number of damaged, but unrecoverable images from the Cassini mission is about 0.01% or less.		Adaptive image coding was used by the [[Cassini-Huygens]] craft to relay images from [[Saturn]]. Only about 5% of the images show any visual signs of damage. As the spacecraft has an error correcting [[Solid-state drive\|Flash drive]] and long timeframes between image taking events, damaged images like this can be present. It is assumed that the number of damaged, but unrecoverable images from the Cassini mission is about 0.01% or less.{{Update inline\|date=December 2019\|reason=How many of the images were actually damaged, now that the mission has ended?}}

	[[Image:Damaged N00153918.jpg\|thumb\|center\|450px\|The Cassini camera was pointing toward DIONE at a distance of approximately 548,210 kilometers. The image was taken using the CL1 and CL2 filters on May 17, 2010.]]		[[Image:Damaged N00153918.jpg\|thumb\|center\|450px\|The Cassini camera was pointing toward DIONE at a distance of approximately 548,210 kilometers. The image was taken using the CL1 and CL2 filters on May 17, 2010.]]

Jarble: linking

2019-11-13T16:39:21Z

linking

← Previous revision		Revision as of 16:39, 13 November 2019
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	{{unreferenced\|date=June 2009\|bot=yes}}		{{unreferenced\|date=June 2009\|bot=yes}}
	'''Adaptive coding''' refers to variants of [[entropy encoding]] methods of [[lossless data compression]]. They are particularly suited to streaming data, as they adapt to localized changes in the characteristics of the data, and don't require a first pass over the data to calculate a probability model. The cost paid for these advantages is that the encoder and decoder must be more complex to keep their states synchronized, and more computational power is needed to keep adapting the encoder/decoder state.		'''Adaptive coding''' refers to variants of [[entropy encoding]] methods of [[lossless data compression]]. They are particularly suited to [[streaming data]], as they adapt to localized changes in the characteristics of the data, and don't require a first pass over the data to calculate a probability model. The cost paid for these advantages is that the encoder and decoder must be more complex to keep their states synchronized, and more computational power is needed to keep adapting the encoder/decoder state.

	Almost all [[data compression]] methods involve the use of a ''model'', a prediction of the composition of the data. When the data matches the prediction made by the model, the encoder can usually transmit the content of the data at a lower information cost, by making reference to the model.		Almost all [[data compression]] methods involve the use of a ''model'', a prediction of the composition of the data. When the data matches the prediction made by the model, the encoder can usually transmit the content of the data at a lower information cost, by making reference to the model.

121.210.75.180: Fixed type resent->present

2019-06-06T04:57:05Z

Fixed type resent->present

← Previous revision		Revision as of 04:57, 6 June 2019
Line 40:		Line 40:

	== Examples ==		== Examples ==
	Adaptive image coding is currently being used by the [[Cassini-Huygens]] craft to relay images from [[Saturn]]. Only about 5% of the images show any visual signs of damage. As the spacecraft has an error correcting [[Solid-state drive\|Flash drive]] and long timeframes between image taking events, damaged images like this can be ~~resent~~. It is assumed that the number of damaged, but unrecoverable images from the Cassini mission is about 0.01% or less.		Adaptive image coding is currently being used by the [[Cassini-Huygens]] craft to relay images from [[Saturn]]. Only about 5% of the images show any visual signs of damage. As the spacecraft has an error correcting [[Solid-state drive\|Flash drive]] and long timeframes between image taking events, damaged images like this can be present. It is assumed that the number of damaged, but unrecoverable images from the Cassini mission is about 0.01% or less.

	[[Image:Damaged N00153918.jpg\|thumb\|center\|450px\|The Cassini camera was pointing toward DIONE at a distance of approximately 548,210 kilometers. The image was taken using the CL1 and CL2 filters on May 17, 2010.]]		[[Image:Damaged N00153918.jpg\|thumb\|center\|450px\|The Cassini camera was pointing toward DIONE at a distance of approximately 548,210 kilometers. The image was taken using the CL1 and CL2 filters on May 17, 2010.]]