Adam7 algorithm - Revision history

AnomieBOT: Dating maintenance tags: {{Why}}

2024-02-18T07:09:08Z

Dating maintenance tags: {{Why}}

← Previous revision		Revision as of 07:09, 18 February 2024
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	Iterating again yields the 7-pass Adam7 scheme, where the first pass (1/8)<sup>2</sup> = 1/64 (1.5625%) of the image.		Iterating again yields the 7-pass Adam7 scheme, where the first pass (1/8)<sup>2</sup> = 1/64 (1.5625%) of the image.

	In principle this can be iterated, yielding a 9-pass scheme, an 11-pass scheme, and so forth, or alternatively an adaptive number of passes can be used, as many as the image size will allow (so the first pass consists of a single pixel), as is usual in scale-free multiscale modeling. In the context that PNG was developed (i.e., for the image sizes and connection speeds in question), a 7-pass scheme was seen as sufficient,{{why}} and preferable to a simple 5-pass scheme.		In principle this can be iterated, yielding a 9-pass scheme, an 11-pass scheme, and so forth, or alternatively an adaptive number of passes can be used, as many as the image size will allow (so the first pass consists of a single pixel), as is usual in scale-free multiscale modeling. In the context that PNG was developed (i.e., for the image sizes and connection speeds in question), a 7-pass scheme was seen as sufficient,{{why\|date=February 2024}} and preferable to a simple 5-pass scheme.

	== References ==		== References ==

Hexware: /* Iteration */

2024-02-18T05:08:51Z

Iteration

← Previous revision		Revision as of 05:08, 18 February 2024
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	Iterating again yields the 7-pass Adam7 scheme, where the first pass (1/8)<sup>2</sup> = 1/64 (1.5625%) of the image.		Iterating again yields the 7-pass Adam7 scheme, where the first pass (1/8)<sup>2</sup> = 1/64 (1.5625%) of the image.

	In principle this can be iterated, yielding a 9-pass scheme, an 11-pass scheme, and so forth, or alternatively an adaptive number of passes can be used, as many as the image size will allow (so the first pass consists of a single pixel), as is usual in scale-free multiscale modeling. In the context that PNG was developed (i.e., for the image sizes and connection speeds in question), a 7-pass scheme was seen as sufficient, and preferable to a simple 5-pass scheme.		In principle this can be iterated, yielding a 9-pass scheme, an 11-pass scheme, and so forth, or alternatively an adaptive number of passes can be used, as many as the image size will allow (so the first pass consists of a single pixel), as is usual in scale-free multiscale modeling. In the context that PNG was developed (i.e., for the image sizes and connection speeds in question), a 7-pass scheme was seen as sufficient,{{why}} and preferable to a simple 5-pass scheme.

	== References ==		== References ==

Ffffrr: Importing Wikidata short description: "Interlacing algorithm for raster images" (Shortdesc helper)

2022-03-27T02:14:14Z

Importing Wikidata short description: "Interlacing algorithm for raster images" (Shortdesc helper)

← Previous revision		Revision as of 02:14, 27 March 2022
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			{{Short description\|Interlacing algorithm for raster images}}
	{{About\|the interlacing scheme for images\|the gene\|ADAM7}}		{{About\|the interlacing scheme for images\|the gene\|ADAM7}}
	[[Image:Adam7 passes.gif\|thumb\|right\|An illustration of Adam7 interlacing over a 16×16 image]]		[[Image:Adam7 passes.gif\|thumb\|right\|An illustration of Adam7 interlacing over a 16×16 image]]

ಮಲ್ನಾಡಾಚ್ ಕೊಂಕ್ಣೊ: Fixed Linter errors

2021-03-24T11:36:36Z

Fixed Linter errors

← Previous revision		Revision as of 11:36, 24 March 2021
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	'''Adam7''' is an [[interlacing (bitmaps)\|interlacing]] [[algorithm]] for [[raster image]]s, best known as the interlacing scheme optionally used in [[Portable Network Graphics\|PNG]] images. An Adam7 interlaced image is broken into seven subimages, which are defined by replicating this 8×8 pattern across the full image.		'''Adam7''' is an [[interlacing (bitmaps)\|interlacing]] [[algorithm]] for [[raster image]]s, best known as the interlacing scheme optionally used in [[Portable Network Graphics\|PNG]] images. An Adam7 interlaced image is broken into seven subimages, which are defined by replicating this 8×8 pattern across the full image.

		⚫	{\| style="margin: 1em auto; background: transparent;"
	<center>
⚫	{\| style="background: transparent;"
	\|		\|
	<pre>1 6 4 6 2 6 4 6		<pre>1 6 4 6 2 6 4 6
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	7 7 7 7 7 7 7 7		7 7 7 7 7 7 7 7
	</pre>		</pre>
			\|}
	\|}</center>

	The subimages are then stored in the image file in numerical order.		The subimages are then stored in the image file in numerical order.
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	It is a rearrangement<ref>{{cite mailing list \|title= interlacing revisited: the Adam7 scheme \|date= 2 Feb 1995 \|accessdate=2016-04-18 \|mailing-list= png-list \|last= Costello \|first= Adam M. \|quote= I rearranged the Lee7 scheme a bit (Lee7 is the obvious extension to Lee's 5-pass scheme), coming up with the Adam7 scheme \|url= http://pmt.sourceforge.net/mailing-lists/png-list/png-list.199502.gz }}</ref> of this five-pass scheme<ref>{{cite mailing list \|title= Interlace methods: visual testing \|date= 1 Feb 1995 \|accessdate=2016-04-18 \|mailing-list= png-list \|last= Lane \|first= Tom \|quote= Lee Crocker's 5-pass 2-D interlace proposal \|url= http://pmt.sourceforge.net/mailing-lists/png-list/png-list.199502.gz }}</ref> that had earlier been proposed by [[Lee Daniel Crocker]]:		It is a rearrangement<ref>{{cite mailing list \|title= interlacing revisited: the Adam7 scheme \|date= 2 Feb 1995 \|accessdate=2016-04-18 \|mailing-list= png-list \|last= Costello \|first= Adam M. \|quote= I rearranged the Lee7 scheme a bit (Lee7 is the obvious extension to Lee's 5-pass scheme), coming up with the Adam7 scheme \|url= http://pmt.sourceforge.net/mailing-lists/png-list/png-list.199502.gz }}</ref> of this five-pass scheme<ref>{{cite mailing list \|title= Interlace methods: visual testing \|date= 1 Feb 1995 \|accessdate=2016-04-18 \|mailing-list= png-list \|last= Lane \|first= Tom \|quote= Lee Crocker's 5-pass 2-D interlace proposal \|url= http://pmt.sourceforge.net/mailing-lists/png-list/png-list.199502.gz }}</ref> that had earlier been proposed by [[Lee Daniel Crocker]]:
		⚫	{\| style="margin: 1em auto; background: transparent;"
	<center>
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	\|-----		\|-----
	\|		\|
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	5 4 5 4		5 4 5 4
	</pre>		</pre>
			\|}
	\|}</center>
	Alternative speculative proposals at the time included square spiral interlacing and using [[Peano curve]]s, but these were rejected as being overcomplicated.		Alternative speculative proposals at the time included square spiral interlacing and using [[Peano curve]]s, but these were rejected as being overcomplicated.

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	=== Iteration ===		=== Iteration ===
	Adam7 arises from iteration of the following pattern:		Adam7 arises from iteration of the following pattern:
		⚫	{\| style="margin: 1em auto; background: transparent;"
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⚫	{\| style="background: transparent;"
	\|-----		\|-----
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	33		33
	</pre>		</pre>
			\|}
	\|}</center>
	which may be interpreted as "folding" in the vertical and horizontal dimensions. Similarly, GIF interlacing {{samp\|1324}} can be seen as iteration of the {{samp\|12}} pattern, but only in the vertical direction ({{samp\|12}} expands to {{samp\|1.2.}} which is filled in as {{samp\|1324}}).		which may be interpreted as "folding" in the vertical and horizontal dimensions. Similarly, GIF interlacing {{samp\|1324}} can be seen as iteration of the {{samp\|12}} pattern, but only in the vertical direction ({{samp\|12}} expands to {{samp\|1.2.}} which is filled in as {{samp\|1324}}).

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	Iterating this pattern once yields a 5-pass scheme; after 3 passes this yields		Iterating this pattern once yields a 5-pass scheme; after 3 passes this yields
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	<center>
⚫	{\| style="background: transparent;"
	\|-----		\|-----
	\|		\|
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	. . . .		. . . .
	</pre>		</pre>
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	\|}</center>
	which is then filled in to:		which is then filled in to:
		⚫	{\| style="margin: 1em auto; background: transparent;"
	<center>
⚫	{\| style="background: transparent;"
	\|-----		\|-----
	\|		\|
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	5 5 5 5		5 5 5 5
	</pre>		</pre>
			\|}
	\|}</center>
	In the 5-pass pattern, the first pass (1/4)<sup>2</sup> = 1/16 (6.25%) of the image.		In the 5-pass pattern, the first pass (1/4)<sup>2</sup> = 1/16 (6.25%) of the image.

Mike Richardson: Undid revision 961484744 by InternetArchiveBot (talk)

2021-01-18T17:34:18Z

Undid revision 961484744 by InternetArchiveBot (talk)

← Previous revision		Revision as of 17:34, 18 January 2021
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	==External links==		==External links==
	* [~~https~~://~~web~~.~~archive.org/web/20051104211607/http://~~schaik.com/png/adam7.html Animated comparison of Adam7 and GIF interlacing]		* [http://www.schaik.com/png/adam7.html Animated comparison of Adam7 and GIF interlacing]

	[[Category:Lossless compression algorithms]]		[[Category:Lossless compression algorithms]]

Monkbot: Task 18 (cosmetic): eval 2 templates: del empty params (2×); hyphenate params (2×);

2020-11-29T22:11:43Z

Task 18 (cosmetic): eval 2 templates: del empty params (2×); hyphenate params (2×);

← Previous revision		Revision as of 22:11, 29 November 2020
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	Adam7 is named after Adam M. Costello, who suggested the method on February 2, 1995, and after the seven steps involved.		Adam7 is named after Adam M. Costello, who suggested the method on February 2, 1995, and after the seven steps involved.

	It is a rearrangement<ref>{{cite mailing list \|title= interlacing revisited: the Adam7 scheme \|date= 2 Feb 1995 \|accessdate=2016-04-18 \|~~mailinglist~~= png-list \|last= Costello \|first= Adam M. \|quote= I rearranged the Lee7 scheme a bit (Lee7 is the obvious extension to Lee's 5-pass scheme), coming up with the Adam7 scheme \|url= http://pmt.sourceforge.net/mailing-lists/png-list/png-list.199502.gz ~~\|ref=~~ }}</ref> of this five-pass scheme<ref>{{cite mailing list \|title= Interlace methods: visual testing \|date= 1 Feb 1995 \|accessdate=2016-04-18 \|~~mailinglist~~= png-list \|last= Lane \|first= Tom \|quote= Lee Crocker's 5-pass 2-D interlace proposal \|url= http://pmt.sourceforge.net/mailing-lists/png-list/png-list.199502.gz ~~\|ref=~~ }}</ref> that had earlier been proposed by [[Lee Daniel Crocker]]:		It is a rearrangement<ref>{{cite mailing list \|title= interlacing revisited: the Adam7 scheme \|date= 2 Feb 1995 \|accessdate=2016-04-18 \|mailing-list= png-list \|last= Costello \|first= Adam M. \|quote= I rearranged the Lee7 scheme a bit (Lee7 is the obvious extension to Lee's 5-pass scheme), coming up with the Adam7 scheme \|url= http://pmt.sourceforge.net/mailing-lists/png-list/png-list.199502.gz }}</ref> of this five-pass scheme<ref>{{cite mailing list \|title= Interlace methods: visual testing \|date= 1 Feb 1995 \|accessdate=2016-04-18 \|mailing-list= png-list \|last= Lane \|first= Tom \|quote= Lee Crocker's 5-pass 2-D interlace proposal \|url= http://pmt.sourceforge.net/mailing-lists/png-list/png-list.199502.gz }}</ref> that had earlier been proposed by [[Lee Daniel Crocker]]:
	<center>		<center>
	{\| style="background: transparent;"		{\| style="background: transparent;"

InternetArchiveBot: Rescuing 1 sources and tagging 0 as dead.) #IABot (v2.0.1

2020-06-08T19:04:55Z

Rescuing 1 sources and tagging 0 as dead.) #IABot (v2.0.1

← Previous revision		Revision as of 19:04, 8 June 2020
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	==External links==		==External links==
	* [~~http~~://~~www~~.schaik.com/png/adam7.html Animated comparison of Adam7 and GIF interlacing]		* [https://web.archive.org/web/20051104211607/http://schaik.com/png/adam7.html Animated comparison of Adam7 and GIF interlacing]

	[[Category:Lossless compression algorithms]]		[[Category:Lossless compression algorithms]]

Ira Leviton: Fixed my coding error. Reminder to self: Always use the 'show preview' button.

2019-10-09T22:57:30Z

Fixed my coding error. Reminder to self: *Always* use the 'show preview' button.

← Previous revision		Revision as of 22:57, 9 October 2019
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	</pre>		</pre>
	\|}</center>		\|}</center>
	which may be interpreted as "folding" in the vertical and horizontal dimensions. Similarly, GIF interlacing {{samp\|1324}} can be seen as iteration of the {{samp\|12}} pattern, but only in the vertical direction ({{samp\|12<}} expands to {{samp\|1.2.}} which is filled in as {{samp\|1324}}).		which may be interpreted as "folding" in the vertical and horizontal dimensions. Similarly, GIF interlacing {{samp\|1324}} can be seen as iteration of the {{samp\|12}} pattern, but only in the vertical direction ({{samp\|12}} expands to {{samp\|1.2.}} which is filled in as {{samp\|1324}}).

	Using this 3-pass pattern means the first pass is (1/2)<sup>2</sup> = 1/4 (25%) of the image.		Using this 3-pass pattern means the first pass is (1/2)<sup>2</sup> = 1/4 (25%) of the image.

Ira Leviton: Replaced html coding found by Wikipedia:Typo Team/moss with wikicoding.

2019-10-09T22:56:43Z

Replaced html coding found by Wikipedia:Typo Team/moss with wikicoding.

← Previous revision		Revision as of 22:56, 9 October 2019
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	</pre>		</pre>
	\|}</center>		\|}</center>
	which may be interpreted as "folding" in the vertical and horizontal dimensions. Similarly, GIF interlacing ~~<tt>~~1324~~</tt>~~ can be seen as iteration of the ~~<tt>~~12~~</tt>~~ pattern, but only in the vertical direction (~~<tt>~~12<~~/tt>~~ expands to ~~<tt>~~1.2.~~</tt>~~ which is filled in as ~~<tt>~~1324~~</tt>~~).		which may be interpreted as "folding" in the vertical and horizontal dimensions. Similarly, GIF interlacing {{samp\|1324}} can be seen as iteration of the {{samp\|12}} pattern, but only in the vertical direction ({{samp\|12<}} expands to {{samp\|1.2.}} which is filled in as {{samp\|1324}}).

	Using this 3-pass pattern means the first pass is (1/2)<sup>2</sup> = 1/4 (25%) of the image.		Using this 3-pass pattern means the first pass is (1/2)<sup>2</sup> = 1/4 (25%) of the image.

Tavix: hatnote adjustment

2018-01-23T20:35:12Z

hatnote adjustment

← Previous revision		Revision as of 20:35, 23 January 2018
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	{{About\|the interlacing scheme for images\|~~\|Adam7~~ ~~(disambiguation){{!}}Adam7~~}}		{{About\|the interlacing scheme for images\|the gene\|ADAM7}}
	[[Image:Adam7 passes.gif\|thumb\|right\|An illustration of Adam7 interlacing over a 16×16 image]]		[[Image:Adam7 passes.gif\|thumb\|right\|An illustration of Adam7 interlacing over a 16×16 image]]
	[[Image:Adam7 interlacing representation.gif\|thumb\|right\|An image being displayed using the Adam7 algorithm.]]		[[Image:Adam7 interlacing representation.gif\|thumb\|right\|An image being displayed using the Adam7 algorithm.]]

← Previous revision		Revision as of 02:14, 27 March 2022
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			{{Short description\|Interlacing algorithm for raster images}}
	{{About\|the interlacing scheme for images\|the gene\|ADAM7}}		{{About\|the interlacing scheme for images\|the gene\|ADAM7}}
	[[Image:Adam7 passes.gif\|thumb\|right\|An illustration of Adam7 interlacing over a 16×16 image]]		[[Image:Adam7 passes.gif\|thumb\|right\|An illustration of Adam7 interlacing over a 16×16 image]]

← Previous revision		Revision as of 20:35, 23 January 2018
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	{{About\|the interlacing scheme for images\|~~\|Adam7~~ ~~(disambiguation){{!}}Adam7~~}}		{{About\|the interlacing scheme for images\|the gene\|ADAM7}}
	[[Image:Adam7 passes.gif\|thumb\|right\|An illustration of Adam7 interlacing over a 16×16 image]]		[[Image:Adam7 passes.gif\|thumb\|right\|An illustration of Adam7 interlacing over a 16×16 image]]
	[[Image:Adam7 interlacing representation.gif\|thumb\|right\|An image being displayed using the Adam7 algorithm.]]		[[Image:Adam7 interlacing representation.gif\|thumb\|right\|An image being displayed using the Adam7 algorithm.]]