Levels - Revision history

Reel.Deal: add link to avs+ documentation

2022-09-17T07:35:04Z

add link to avs+ documentation

← Older revision		Revision as of 09:35, 17 September 2022
Line 1:		Line 1:
	<div style="max-width:62em" >		<div style="max-width:62em" >

			<div {{BlueBox2\|40\|0\|3px solid purple}} >
			{{AvsPlusFullname}}<br>
			Up-to-date documentation: [https://avisynthplus.readthedocs.io/en/latest/avisynthdoc/corefilters/levels.html https://avisynthplus.readthedocs.io]
			</div>


	Adjusts brightness, contrast, and gamma. This is done using the following ''transfer function'':		Adjusts brightness, contrast, and gamma. This is done using the following ''transfer function'':
	:''output'' = ( (''input'' - {{FuncArg\|input_low}}) / ({{FuncArg\|input_high}} - {{FuncArg\|input_low}}) )<sup>(1 / {{FuncArg\|gamma}})</sup> * ({{FuncArg\|output_high}} - {{FuncArg\|output_low}}) + {{FuncArg\|output_low}}		:''output'' = ( (''input'' - {{FuncArg\|input_low}}) / ({{FuncArg\|input_high}} - {{FuncArg\|input_low}}) )<sup>(1 / {{FuncArg\|gamma}})</sup> * ({{FuncArg\|output_high}} - {{FuncArg\|output_low}}) + {{FuncArg\|output_low}}

Reel.Deal: /* Syntax and Parameters */ fix dead link

2022-02-22T00:08:22Z

Syntax and Parameters: fix dead link

← Older revision		Revision as of 02:08, 22 February 2022
Line 102:		Line 102:

	::{{FuncArg\|coring}} was created for VirtualDub compatibility, and it remains true by default for compatibility with older scripts.		::{{FuncArg\|coring}} was created for VirtualDub compatibility, and it remains true by default for compatibility with older scripts.
	::In the opinion of some, you should [http://forum.doom9.org/showthread.php?p=1722885#post1722885 always use ''coring=false''] if you are working directly with luma values (whether or not your input is 16{{D}}-235{{D}}).		::In the opinion of some, you should [https://web.archive.org/web/20160825211112/http://forum.doom9.org/showthread.php?p=1722885#post1722885 always use ''coring=false''] if you are working directly with luma values (whether or not your input is 16{{D}}-235{{D}}).

	::'''Note''' TV-range video ''can'' be correctly processed with {{FuncArg\|coring}}=false; for example,		::'''Note''' TV-range video ''can'' be correctly processed with {{FuncArg\|coring}}=false; for example,
Line 113:		Line 113:
	:{{Par2\|dither\|bool\|false}}		:{{Par2\|dither\|bool\|false}}
	::When ''true'', [[ordered dithering]] is applied to combat [http://en.wikipedia.org/wiki/Colour_banding banding]. Default is ''false''.		::When ''true'', [[ordered dithering]] is applied to combat [http://en.wikipedia.org/wiki/Colour_banding banding]. Default is ''false''.


	==== Examples ====		==== Examples ====

Raffriff42: typo

2018-09-14T03:42:44Z

typo

← Older revision		Revision as of 05:42, 14 September 2018
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	\|style="text-align:right"\|256		\|style="text-align:right"\|256
	\|style="text-align:right"\|2048		\|style="text-align:right"\|2048
	\|style="text-align:right"\|~~3670~~		\|style="text-align:right"\|3760
	\|style="text-align:right"\|4080		\|style="text-align:right"\|4080
	\|-		\|-

Raffriff42: tweak table

2018-01-15T15:51:56Z

tweak table

← Older revision		Revision as of 17:51, 15 January 2018
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	!32		!32
	\|style="text-align:right"\|0.0		\|style="text-align:right"\|0.0
	\|style="text-align:right"\|~~0.0625~~		\|style="text-align:right"\|<sup>16</sup>/<sub>256</sub>
	\|style="text-align:right"\|~~0.5000~~		\|style="text-align:right"\|<sup>128</sup>/<sub>256</sub>
	\|style="text-align:right"\|~~0.9179~~		\|style="text-align:right"\|<sup>235</sup>/<sub>256</sub>
	\|style="text-align:right"\|~~0.9961~~		\|style="text-align:right"\|<sup>255</sup>/<sub>256</sub>
	\|}		\|}

Raffriff42: rephrase & add "bit depth equivalent color value" table

2018-01-13T03:11:30Z

rephrase & add "bit depth equivalent color value" table

← Older revision		Revision as of 05:11, 13 January 2018
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	When processing data in [[YUV]] mode, '''Levels''' only gamma-corrects the luma information, not the chroma. Gamma correction is really an RGB concept, and is only approximated here in YUV. If ''{{FuncArg\|gamma}}=1.0'' (unity), the filter should have the same effect in both RGB and YUV modes. For adjusting brightness or contrast in YUV mode, it ''may'' be better (depending on the effect you are looking for) to use [[Tweak]] or [[ColorYUV]], because '''Levels''' changes the chroma of the clip.		When processing data in [[YUV]] mode, '''Levels''' only gamma-corrects the luma information, not the chroma. Gamma correction is really an RGB concept, and is only approximated here in YUV. If ''{{FuncArg\|gamma}}=1.0'' (unity), the filter should have the same effect in both RGB and YUV modes. For adjusting brightness or contrast in YUV mode, it ''may'' be better (depending on the effect you are looking for) to use [[Tweak]] or [[ColorYUV]], because '''Levels''' changes the chroma of the clip.

	{{AvsPluscon}} ~~all~~ parameters ~~except~~ {{FuncArg\|~~gamma~~}} are ~~''non''-~~[[Autoscale_parameter\|autoscaling]] – they ~~must be scaled~~ to the ~~target~~ bit depth.		Note in {{AvsPluscon}}, the parameters {{FuncArg\|input_low}}, {{FuncArg\|input_high}}, {{FuncArg\|output_low}} and {{FuncArg\|output_high}}
			* are <tt>float</tt> instead of <tt>int</tt>.
			* are not [[Autoscale_parameter\|autoscaling]] – they are relative to the current bit depth:
			:{\| class="wikitable"
			\|-
			\|colspan="6" \|bit depth equivalent color values
			\|-
			!style="text-align:right"\|8
			\|style="text-align:right"\|0
			\|style="text-align:right"\|16
			\|style="text-align:right"\|128
			\|style="text-align:right"\|235
			\|style="text-align:right"\|255
			\|-
			!10
			\|style="text-align:right"\|0
			\|style="text-align:right"\|64
			\|style="text-align:right"\|512
			\|style="text-align:right"\|940
			\|style="text-align:right"\|1020
			\|-
			!12
			\|style="text-align:right"\|0
			\|style="text-align:right"\|256
			\|style="text-align:right"\|2048
			\|style="text-align:right"\|3670
			\|style="text-align:right"\|4080
			\|-
			!14
			\|style="text-align:right"\|0
			\|style="text-align:right"\|1024
			\|style="text-align:right"\|8192
			\|style="text-align:right"\|15040
			\|style="text-align:right"\|16320
			\|-
			!16
			\|style="text-align:right"\|0
			\|style="text-align:right"\|4096
			\|style="text-align:right"\|32768
			\|style="text-align:right"\|60160
			\|style="text-align:right"\|65280
			\|-
			!32
			\|style="text-align:right"\|0.0
			\|style="text-align:right"\|0.0625
			\|style="text-align:right"\|0.5000
			\|style="text-align:right"\|0.9179
			\|style="text-align:right"\|0.9961
			\|}


	==== Syntax and Parameters ====		==== Syntax and Parameters ====
	{{FuncDef\|Levels(clip ''input'', <br>		{{FuncDef\|Levels(clip ''input'', <br>
	int ''input_low'', float ''gamma'', int ''input_high'', <br>		int ''input_low'', float ''gamma'', int ''input_high'', int ''output_low'', int ''output_high''<br>
	~~int~~ ''output_low'', ~~int~~ ''output_high''<br>		[, bool ''coring'' , bool ''dither'' ] )}}<br>
	[, bool ''coring'' , bool ''dither'' ] )}}		{{FuncDef\|Levels(clip ''input'', <br>
			float ''input_low'', float ''gamma'', float ''input_high'', float ''output_low'', float ''output_high''<br>
			[, bool ''coring'' , bool ''dither'' ] )}} {{AvsPluscon}}

	:{{Par2\|clip\|clip\|(required)}}		:{{Par2\|clip\|clip\|(required)}}
	::Source video.		::Source video.

	:{{Par2\|input_low\|int*\|(required)}}		:{{Par2\|input_low\|int/float*\|(required)}}
	::Input values at {{FuncArg\|input_low}} or lower are treated as ''black'', and lighter colors are darkened proportionally.		::Input values at {{FuncArg\|input_low}} or lower are treated as ''black'', and lighter colors are darkened proportionally.
	::Therefore raising {{FuncArg\|input_low}} darkens the output.		::Therefore raising {{FuncArg\|input_low}} darkens the output.
	:: <big></big> ~~{{AvsPluscon}} only – all arguments marked ''~~int'' are floating point (from version r2580)		:: <big>*</big> = <tt>int</tt> in AviSynth, <tt>float</tt> in AviSynth+

	:{{Par2\|gamma\|float\|(required)}}		:{{Par2\|gamma\|float\|(required)}}
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	::Higher {{FuncArg\|gamma}} brightens the output; lower {{FuncArg\|gamma}} darkens the output.		::Higher {{FuncArg\|gamma}} brightens the output; lower {{FuncArg\|gamma}} darkens the output.

	:{{Par2\|input_high\|int*\|(required)}}		:{{Par2\|input_high\|int/float\|(required)}}
	::Input values at {{FuncArg\|input_high}} or higher are treated as ''white'', and darker colors are brightened proportionally.		::Input values at {{FuncArg\|input_high}} or higher are treated as ''white'', and darker colors are brightened proportionally.
	::Therefore lowering {{FuncArg\|input_high}} brightens the output.		::Therefore lowering {{FuncArg\|input_high}} brightens the output.

	:{{Par2\|output_low\|int*\|(required)}}		:{{Par2\|output_low\|int/float\|(required)}}
	::Dark values brighten to gray as {{FuncArg\|output_low}} becomes larger.		::Dark values brighten to gray as {{FuncArg\|output_low}} becomes larger.

	:{{Par2\|output_high\|int*\|(required)}}		:{{Par2\|output_high\|int/float\|(required)}}
	::Light values darken to gray as {{FuncArg\|output_high}} becomes smaller.		::Light values darken to gray as {{FuncArg\|output_high}} becomes smaller.

Raffriff42: AVS+ arguments are float as of r2580

2018-01-12T23:06:37Z

AVS+ arguments are float as of r2580

← Older revision		Revision as of 01:06, 13 January 2018
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	::Source video.		::Source video.

	:{{Par2\|input_low\|int\|(required)}}		:{{Par2\|input_low\|int*\|(required)}}
	::Input values at {{FuncArg\|input_low}} or lower are treated as ''black'', and lighter colors are darkened proportionally.		::Input values at {{FuncArg\|input_low}} or lower are treated as ''black'', and lighter colors are darkened proportionally.
	::Therefore raising {{FuncArg\|input_low}} darkens the output.		::Therefore raising {{FuncArg\|input_low}} darkens the output.
			:: <big></big> {{AvsPluscon}} only – all arguments marked ''int'' are floating point (from version r2580)

	:{{Par2\|gamma\|float\|(required)}}		:{{Par2\|gamma\|float\|(required)}}
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	::Higher {{FuncArg\|gamma}} brightens the output; lower {{FuncArg\|gamma}} darkens the output.		::Higher {{FuncArg\|gamma}} brightens the output; lower {{FuncArg\|gamma}} darkens the output.

	:{{Par2\|input_high\|int\|(required)}}		:{{Par2\|input_high\|int*\|(required)}}
	::Input values at {{FuncArg\|input_high}} or higher are treated as ''white'', and darker colors are brightened proportionally.		::Input values at {{FuncArg\|input_high}} or higher are treated as ''white'', and darker colors are brightened proportionally.
	::Therefore lowering {{FuncArg\|input_high}} brightens the output.		::Therefore lowering {{FuncArg\|input_high}} brightens the output.

	:{{Par2\|output_low\|int\|(required)}}		:{{Par2\|output_low\|int*\|(required)}}
	::Dark values brighten to gray as {{FuncArg\|output_low}} becomes larger.		::Dark values brighten to gray as {{FuncArg\|output_low}} becomes larger.

	:{{Par2\|output_high\|int\|(required)}}		:{{Par2\|output_high\|int*\|(required)}}
	::Light values darken to gray as {{FuncArg\|output_high}} becomes smaller.		::Light values darken to gray as {{FuncArg\|output_high}} becomes smaller.

Line 116:		Line 117:
	[[FadeOut]](n)		[[FadeOut]](n)
	Levels(0, 1.0/gamma, 255, 0, 255) # redo gamma		Levels(0, 1.0/gamma, 255, 0, 255) # redo gamma
			## use AVS+ and bit depth >= 10 to avoid banding in dark areas
	</div>		</div>

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	==== Changes ====		==== Changes ====
	{\|border=1 cellspacing=1 cellpadding=4		{\|border=1 cellspacing=1 cellpadding=4
			\|-
			\| AVS+ r2580
			\| arguments are float
	\|-		\|-
	\| v2.60		\| v2.60

Raffriff42: coring note

2017-12-09T01:04:31Z

coring note

← Older revision		Revision as of 03:04, 9 December 2017
Line 52:		Line 52:
	::{{FuncArg\|coring}} was created for VirtualDub compatibility, and it remains true by default for compatibility with older scripts.		::{{FuncArg\|coring}} was created for VirtualDub compatibility, and it remains true by default for compatibility with older scripts.
	::In the opinion of some, you should [http://forum.doom9.org/showthread.php?p=1722885#post1722885 always use ''coring=false''] if you are working directly with luma values (whether or not your input is 16{{D}}-235{{D}}).		::In the opinion of some, you should [http://forum.doom9.org/showthread.php?p=1722885#post1722885 always use ''coring=false''] if you are working directly with luma values (whether or not your input is 16{{D}}-235{{D}}).

			::'''Note''' TV-range video ''can'' be correctly processed with {{FuncArg\|coring}}=false; for example,
			:::<code>Levels({{BoldColor\|blue\|104\|0}}, 1.6, {{BoldColor\|blue\|104\|255}}, {{BoldColor\|blue\|104\|0}}, {{BoldColor\|blue\|104\|255}}, coring=true)</code>
			::produces the same result as
			:::<code>Levels({{BoldColor\|blue\|104\|16}}, 1.6, {{BoldColor\|blue\|104\|235}}, {{BoldColor\|blue\|104\|16}}, {{BoldColor\|blue\|104\|235}}, coring=false)</code>
			::except that the output is not clipped to TV-range. Black and white levels are preserved while adjusting {{FuncArg\|gamma}}, unlike
			:::<code>Levels(0, 1.6, 255, 0, 255, coring=false)</code>

	:{{Par2\|dither\|bool\|false}}		:{{Par2\|dither\|bool\|false}}

Raffriff42: note AVS+ differences

2017-04-28T20:46:34Z

note AVS+ differences

← Older revision		Revision as of 22:46, 28 April 2017
Line 5:		Line 5:
	*{{FuncArg\|input_low}} and {{FuncArg\|input_high}} determine what ''input'' pixel values are treated as pure black and pure white.		*{{FuncArg\|input_low}} and {{FuncArg\|input_high}} determine what ''input'' pixel values are treated as pure black and pure white.
	*{{FuncArg\|output_low}} and {{FuncArg\|output_high}} determine what ''output'' values are treated as pure black and pure white.		*{{FuncArg\|output_low}} and {{FuncArg\|output_high}} determine what ''output'' values are treated as pure black and pure white.
	*{{FuncArg\|gamma}} controls the degree of non-linearity in the conversion.		*{{FuncArg\|gamma}} controls the degree of non-linearity in the conversion.


	This is one of those filters for which it would really be nice to have a GUI. Since we can't offer a GUI (though [http://forum.doom9.org/showthread.php?t=153248 AvsP] does), we at least make this filter '''compatible''' with [[VirtualDub\|VirtualDub's]] when the clip is [[RGB]]. In that case you should be able to take the numbers from VirtualDub's ''Levels'' dialog and pass them as parameters to the '''Levels''' filter and get the same results. Unlike VirtualDub's filter however, the input and output parameters can be larger than 255.		This is one of those filters for which it would really be nice to have a GUI. Since we can't offer a GUI (though [http://forum.doom9.org/showthread.php?t=153248 AvsP] does), we at least make this filter '''compatible''' with [[VirtualDub\|VirtualDub's]] when the clip is [[RGB]]. In that case you should be able to take the numbers from VirtualDub's ''Levels'' dialog and pass them as parameters to the '''Levels''' filter and get the same results. Unlike VirtualDub's filter however, the input and output parameters can be larger than 255{{D}}.

	When processing data in [[YUV]] mode, '''Levels''' only gamma-corrects the luma information, not the chroma. Gamma correction is really an RGB concept, and is only approximated here in YUV. If ''{{FuncArg\|gamma}}=1.0'' (unity), the filter should have the same effect in both RGB and YUV modes. For adjusting brightness or contrast in YUV mode, it ''may'' be better (depending on the effect you are looking for) to use [[Tweak]] or [[ColorYUV]], because '''Levels''' changes the chroma of the clip.		When processing data in [[YUV]] mode, '''Levels''' only gamma-corrects the luma information, not the chroma. Gamma correction is really an RGB concept, and is only approximated here in YUV. If ''{{FuncArg\|gamma}}=1.0'' (unity), the filter should have the same effect in both RGB and YUV modes. For adjusting brightness or contrast in YUV mode, it ''may'' be better (depending on the effect you are looking for) to use [[Tweak]] or [[ColorYUV]], because '''Levels''' changes the chroma of the clip.

			{{AvsPluscon}} all parameters except {{FuncArg\|gamma}} are ''non''-[[Autoscale_parameter\|autoscaling]] – they must be scaled to the target bit depth.


Line 42:		Line 44:
	:{{Par2\|coring\|bool\|true}}		:{{Par2\|coring\|bool\|true}}
	::When ''true'' (the default),		::When ''true'' (the default),
	::#input luma is ''clamped'' to the range 16-235 and the chroma to 16-240;		::#input luma is ''clamped'' to the range 16{{D}}-235{{D}} and the chroma to 16{{D}}-240{{D}};
	::#this clamped input is ''scaled'' from 16-235 to 0-255,		::#this clamped input is ''scaled'' from 16{{D}}-235{{D}} to 0{{D}}-255{{D}},
	::#the conversion takes place according to the transfer function above, and then		::#the conversion takes place according to the transfer function above, and then
	::#output is scaled back to 16-235.		::#output is scaled back to 16{{D}}-235{{D}}.
	::When ''false'', the conversion takes place according to the transfer function, without any scaling.		::When ''false'', the conversion takes place according to the transfer function, without any scaling.

	::{{FuncArg\|coring}} was created for VirtualDub compatibility, and it remains true by default for compatibility with older scripts.		::{{FuncArg\|coring}} was created for VirtualDub compatibility, and it remains true by default for compatibility with older scripts.
	::In the opinion of some, you should [http://forum.doom9.org/showthread.php?p=1722885#post1722885 always use ''coring=false''] if you are working directly with luma values (whether or not your input is 16-235).		::In the opinion of some, you should [http://forum.doom9.org/showthread.php?p=1722885#post1722885 always use ''coring=false''] if you are working directly with luma values (whether or not your input is 16{{D}}-235{{D}}).

	:{{Par2\|dither\|bool\|false}}		:{{Par2\|dither\|bool\|false}}
Line 62:		Line 64:

	<div {{BoxWidthIndent\|64\|2}} >		<div {{BoxWidthIndent\|64\|2}} >
	# the input is scaled from [16,235] to [0,255], the conversion [0,255]->[16,235] takes place		# the input is scaled from [16,235] to [0,255],
	# (~~accordingly~~ to the formula), and the output is scaled back from [0,255] to [16,235]		# the conversion [0,255]->[16,235] takes place (according to the formula),
			# and the output is scaled back from [0,255] to [16,235]
	# (for example: the luma values in [0,16] are all converted to 30)		# (for example: the luma values in [0,16] are all converted to 30)
	Levels(0, 1, 255, 16, 235)		Levels(0, 1, 255, 16, 235)

Raffriff42: formatting

2016-02-28T09:14:19Z

formatting

← Older revision		Revision as of 11:14, 28 February 2016
Line 1:		Line 1:
			<div style="max-width:62em" >
	Adjusts brightness, contrast, and gamma. This is done using the following ''transfer function'':		Adjusts brightness, contrast, and gamma. This is done using the following ''transfer function'':
	:''output'' = ( (''input'' - {{FuncArg\|input_low}}) / ({{FuncArg\|input_high}} - {{FuncArg\|input_low}}) )<sup>(1 / {{FuncArg\|gamma}})</sup> * ({{FuncArg\|output_high}} - {{FuncArg\|output_low}}) + {{FuncArg\|output_low}}		:''output'' = ( (''input'' - {{FuncArg\|input_low}}) / ({{FuncArg\|input_high}} - {{FuncArg\|input_low}}) )<sup>(1 / {{FuncArg\|gamma}})</sup> * ({{FuncArg\|output_high}} - {{FuncArg\|output_low}}) + {{FuncArg\|output_low}}
Line 47:		Line 48:
	::When ''false'', the conversion takes place according to the transfer function, without any scaling.		::When ''false'', the conversion takes place according to the transfer function, without any scaling.

	::{{FuncArg\|coring}} was created for VirtualDub compatibility, and it remains true by default for compatibility with older scripts. In the opinion of some, you should [http://forum.doom9.org/showthread.php?p=1722885#post1722885 always use ''coring=false''] if you are working directly with luma values (whether or not your input is 16-235).		::{{FuncArg\|coring}} was created for VirtualDub compatibility, and it remains true by default for compatibility with older scripts.
			::In the opinion of some, you should [http://forum.doom9.org/showthread.php?p=1722885#post1722885 always use ''coring=false''] if you are working directly with luma values (whether or not your input is 16-235).

	:{{Par2\|dither\|bool\|false}}		:{{Par2\|dither\|bool\|false}}
Line 116:		Line 118:
	\| added ''coring'' (true by default, which reflects the behaviour in older versions)		\| added ''coring'' (true by default, which reflects the behaviour in older versions)
	\|}		\|}
			</div>

	[[Category:Internal filters]]		[[Category:Internal filters]]
	[[Category:Levels and Chroma filters]]		[[Category:Levels and Chroma filters]]

Raffriff42: format ''coring'', remove redundant example #5

2016-01-19T11:54:40Z

format ''coring'', remove redundant example #5

← Older revision		Revision as of 13:54, 19 January 2016
Line 39:		Line 39:
	::Light values darken to gray as {{FuncArg\|output_high}} becomes smaller.		::Light values darken to gray as {{FuncArg\|output_high}} becomes smaller.

	:{{Par2\|coring\|bool\|~~false~~}}		:{{Par2\|coring\|bool\|true}}
	::When ''true'' (the default), input luma is ''clamped'' to [16,235] and the chroma to [16,240]; this clamped input is scaled from [16,235] to [0,255], the conversion takes place according to the transfer function above, and then output is scaled back ~~from [0,255]~~ to [16,235]. When ''false'', the conversion takes place according to the transfer function, without any scaling.		::When ''true'' (the default),
			::#input luma is ''clamped'' to the range 16-235 and the chroma to 16-240;
			::#this clamped input is ''scaled'' from 16-235 to 0-255,
			::#the conversion takes place according to the transfer function above, and then
			::#output is scaled back to 16-235.
			::When ''false'', the conversion takes place according to the transfer function, without any scaling.

	::{{FuncArg\|coring}} was created for VirtualDub compatibility, and it remains true by default for compatibility with older scripts. In the opinion of some, you should [http://forum.doom9.org/showthread.php?p=1722885#post1722885 always use ''coring=false''] if you are working directly with luma values (whether or not your input is [16,235]).		::{{FuncArg\|coring}} was created for VirtualDub compatibility, and it remains true by default for compatibility with older scripts. In the opinion of some, you should [http://forum.doom9.org/showthread.php?p=1722885#post1722885 always use ''coring=false''] if you are working directly with luma values (whether or not your input is 16-235).

	:{{Par2\|dither\|bool\|false}}		:{{Par2\|dither\|bool\|false}}
Line 71:		Line 76:
	# example: luma of 16 is converted to 235		# example: luma of 16 is converted to 235
	Levels(0, 1, 255, 255, 0)		Levels(0, 1, 255, 255, 0)
	~~</div>~~

	~~<div {{BoxWidthIndent\|64\|2}} >~~
	~~# does nothing on a [0,255] clip; does nothing on a [16,235]:~~
	~~Levels(0, 1, 255, 0, 255, coring=false)~~
	</div>		</div>

Line 98:		Line 98:

	<div {{BoxWidthIndent\|64\|2}} >		<div {{BoxWidthIndent\|64\|2}} >
	# apply fading on gamma corrected source (same holds for resizing and smoothing ~~else well~~)		# apply fading on gamma corrected source (same holds for resizing and smoothing)
	clip = ...		clip = ...
	gamma = 2.2		gamma = 2.2

← Older revision		Revision as of 05:42, 14 September 2018
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	\|style="text-align:right"\|256		\|style="text-align:right"\|256
	\|style="text-align:right"\|2048		\|style="text-align:right"\|2048
	\|style="text-align:right"\|~~3670~~		\|style="text-align:right"\|3760
	\|style="text-align:right"\|4080		\|style="text-align:right"\|4080
	\|-		\|-

← Older revision		Revision as of 17:51, 15 January 2018
Line 56:		Line 56:
	!32		!32
	\|style="text-align:right"\|0.0		\|style="text-align:right"\|0.0
	\|style="text-align:right"\|~~0.0625~~		\|style="text-align:right"\|<sup>16</sup>/<sub>256</sub>
	\|style="text-align:right"\|~~0.5000~~		\|style="text-align:right"\|<sup>128</sup>/<sub>256</sub>
	\|style="text-align:right"\|~~0.9179~~		\|style="text-align:right"\|<sup>235</sup>/<sub>256</sub>
	\|style="text-align:right"\|~~0.9961~~		\|style="text-align:right"\|<sup>255</sup>/<sub>256</sub>
	\|}		\|}

← Older revision		Revision as of 05:11, 13 January 2018
Line 12:		Line 12:
	When processing data in [[YUV]] mode, '''Levels''' only gamma-corrects the luma information, not the chroma. Gamma correction is really an RGB concept, and is only approximated here in YUV. If ''{{FuncArg\|gamma}}=1.0'' (unity), the filter should have the same effect in both RGB and YUV modes. For adjusting brightness or contrast in YUV mode, it ''may'' be better (depending on the effect you are looking for) to use [[Tweak]] or [[ColorYUV]], because '''Levels''' changes the chroma of the clip.		When processing data in [[YUV]] mode, '''Levels''' only gamma-corrects the luma information, not the chroma. Gamma correction is really an RGB concept, and is only approximated here in YUV. If ''{{FuncArg\|gamma}}=1.0'' (unity), the filter should have the same effect in both RGB and YUV modes. For adjusting brightness or contrast in YUV mode, it ''may'' be better (depending on the effect you are looking for) to use [[Tweak]] or [[ColorYUV]], because '''Levels''' changes the chroma of the clip.

	{{AvsPluscon}} ~~all~~ parameters ~~except~~ {{FuncArg\|~~gamma~~}} are ~~''non''-~~[[Autoscale_parameter\|autoscaling]] – they ~~must be scaled~~ to the ~~target~~ bit depth.		Note in {{AvsPluscon}}, the parameters {{FuncArg\|input_low}}, {{FuncArg\|input_high}}, {{FuncArg\|output_low}} and {{FuncArg\|output_high}}
			* are <tt>float</tt> instead of <tt>int</tt>.
			* are not [[Autoscale_parameter\|autoscaling]] – they are relative to the current bit depth:
			:{\| class="wikitable"
			\|-
			\|colspan="6" \|bit depth equivalent color values
			\|-
			!style="text-align:right"\|8
			\|style="text-align:right"\|0
			\|style="text-align:right"\|16
			\|style="text-align:right"\|128
			\|style="text-align:right"\|235
			\|style="text-align:right"\|255
			\|-
			!10
			\|style="text-align:right"\|0
			\|style="text-align:right"\|64
			\|style="text-align:right"\|512
			\|style="text-align:right"\|940
			\|style="text-align:right"\|1020
			\|-
			!12
			\|style="text-align:right"\|0
			\|style="text-align:right"\|256
			\|style="text-align:right"\|2048
			\|style="text-align:right"\|3670
			\|style="text-align:right"\|4080
			\|-
			!14
			\|style="text-align:right"\|0
			\|style="text-align:right"\|1024
			\|style="text-align:right"\|8192
			\|style="text-align:right"\|15040
			\|style="text-align:right"\|16320
			\|-
			!16
			\|style="text-align:right"\|0
			\|style="text-align:right"\|4096
			\|style="text-align:right"\|32768
			\|style="text-align:right"\|60160
			\|style="text-align:right"\|65280
			\|-
			!32
			\|style="text-align:right"\|0.0
			\|style="text-align:right"\|0.0625
			\|style="text-align:right"\|0.5000
			\|style="text-align:right"\|0.9179
			\|style="text-align:right"\|0.9961
			\|}


	==== Syntax and Parameters ====		==== Syntax and Parameters ====
	{{FuncDef\|Levels(clip ''input'', <br>		{{FuncDef\|Levels(clip ''input'', <br>
	int ''input_low'', float ''gamma'', int ''input_high'', <br>		int ''input_low'', float ''gamma'', int ''input_high'', int ''output_low'', int ''output_high''<br>
	~~int~~ ''output_low'', ~~int~~ ''output_high''<br>		[, bool ''coring'' , bool ''dither'' ] )}}<br>
	[, bool ''coring'' , bool ''dither'' ] )}}		{{FuncDef\|Levels(clip ''input'', <br>
			float ''input_low'', float ''gamma'', float ''input_high'', float ''output_low'', float ''output_high''<br>
			[, bool ''coring'' , bool ''dither'' ] )}} {{AvsPluscon}}

	:{{Par2\|clip\|clip\|(required)}}		:{{Par2\|clip\|clip\|(required)}}
	::Source video.		::Source video.

	:{{Par2\|input_low\|int*\|(required)}}		:{{Par2\|input_low\|int/float*\|(required)}}
	::Input values at {{FuncArg\|input_low}} or lower are treated as ''black'', and lighter colors are darkened proportionally.		::Input values at {{FuncArg\|input_low}} or lower are treated as ''black'', and lighter colors are darkened proportionally.
	::Therefore raising {{FuncArg\|input_low}} darkens the output.		::Therefore raising {{FuncArg\|input_low}} darkens the output.
	:: <big></big> ~~{{AvsPluscon}} only – all arguments marked ''~~int'' are floating point (from version r2580)		:: <big>*</big> = <tt>int</tt> in AviSynth, <tt>float</tt> in AviSynth+

	:{{Par2\|gamma\|float\|(required)}}		:{{Par2\|gamma\|float\|(required)}}
Line 33:		Line 83:
	::Higher {{FuncArg\|gamma}} brightens the output; lower {{FuncArg\|gamma}} darkens the output.		::Higher {{FuncArg\|gamma}} brightens the output; lower {{FuncArg\|gamma}} darkens the output.

	:{{Par2\|input_high\|int*\|(required)}}		:{{Par2\|input_high\|int/float\|(required)}}
	::Input values at {{FuncArg\|input_high}} or higher are treated as ''white'', and darker colors are brightened proportionally.		::Input values at {{FuncArg\|input_high}} or higher are treated as ''white'', and darker colors are brightened proportionally.
	::Therefore lowering {{FuncArg\|input_high}} brightens the output.		::Therefore lowering {{FuncArg\|input_high}} brightens the output.

	:{{Par2\|output_low\|int*\|(required)}}		:{{Par2\|output_low\|int/float\|(required)}}
	::Dark values brighten to gray as {{FuncArg\|output_low}} becomes larger.		::Dark values brighten to gray as {{FuncArg\|output_low}} becomes larger.

	:{{Par2\|output_high\|int*\|(required)}}		:{{Par2\|output_high\|int/float\|(required)}}
	::Light values darken to gray as {{FuncArg\|output_high}} becomes smaller.		::Light values darken to gray as {{FuncArg\|output_high}} becomes smaller.