SGradation - Revision history

Raffriff42: added SGradation2, SGradation2S

2013-08-24T18:29:57Z

added SGradation2, SGradation2S

← Older revision		Revision as of 20:29, 24 August 2013
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	# similar to the well known gamma. Values below 1.0 reduce contrast.		# similar to the well known gamma. Values below 1.0 reduce contrast.
	#		#
	~~# int median~~
	~~# the luma center point - default 128.~~
	#		#
	# float ~~darkgamma~~, ~~lightgamma~~		# float gammaB, gammaW
	# allow separate gamma values for the dark/light part of the image.		# allow separate gamma values for the dark/light part of the image.
	#		#
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	#		#
	function SGradation(clip clp, val "gamma") {		function SGradation(clip clp, val "gamma") {
	g=~~float~~(~~default~~(gamma,1.0))		g=Float(Default(gamma, 1.0))
	gc=clp.GreyScale()#.ColorYUV(levels="TV->PC")		gc=clp.GreyScale() #.ColorYUV(levels="TV->PC")
	dk=gc.Levels(0,1.0/g,127,0,127)		dk=gc.Levels(0,1.0/g,127,0,127)
	lt=gc.Levels(235,1.0/g,128,107,0,coring=false)		lt=gc.Levels(235,1.0/g,128,107,0,coring=false)
	# dk=gc.Levels(127,g,0,127,0)		# dk=gc.Levels(127,g,0,127,0)
	# lt=gc.Levels(128,g,235,0,107,coring=false)		# lt=gc.Levels(128,g,235,0,107,coring=false)
	r=Overlay(dk,lt,mode="add")		r=Overlay(dk,lt,mode="add")
	r.MergeChroma(clp)#.ColorYUV(levels="PC->TV")		r.MergeChroma(clp) #.ColorYUV(levels="PC->TV")
	}		}

			## independent control of highlights & lowlights
			#
			function SGradation2(clip clp, val "gammaW", val "gammaB")
			{
			gW = Float(Default(gammaW, 1.0))
			gB = Float(Default(gammaB, 1.0))

			gc = clp.GreyScale()

			dk = gc.Levels( 0, 1.0/gB, 127, 0, 127)
			lt = gc.Levels(235, 1.0/gW, 128, 107, 0, coring=false)

			r = Overlay(dk, lt, mode="add")
			r.MergeChroma(clp)
			}

			## independent control of highlights & lowlights with debanding
			## http://forum.doom9.org/showthread.php?p=1637727#post1637727
			## requires SmoothAdjust
			## http://forum.doom9.org/showthread.php?t=154971
			#
			function SGradation2S(clip clp, val "gammaW", val "gammaB")
			{
			gW = Float(Default(gammaW, 1.0))
			gB = Float(Default(gammaB, 1.0))

			gc = clp.GreyScale()

			dk = gc.SmoothLevels( 16, 1.0/gB, 127, 16, 127, smooth=200, limiter=1)
			lt = gc.SmoothLevels(235, 1.0/gW, 128, 107, 0, smooth=200)

			r = Overlay(dk, lt, mode="add")
			r.MergeChroma(clp)
			}

	Back to [[Shared functions]].		Back to [[Shared functions]].

	[[Category:Shared_functions]]		[[Category:Shared_functions]]
	[[Category:External filters]]		[[Category:External filters]]

Admin: 1 revision

2013-05-19T22:03:19Z

1 revision

← Older revision	Revision as of 00:03, 20 May 2013
(No difference)

Wilbert at 21:35, 18 May 2013

2013-05-18T21:35:57Z

← Older revision		Revision as of 23:35, 18 May 2013
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	Back to [[Shared functions]].		Back to [[Shared functions]].

	[[Category:Shared_functions]]		[[Category:Shared_functions]]
			[[Category:External filters]]

Admin: 1 revision

2013-05-09T21:34:46Z

1 revision

← Older revision	Revision as of 23:34, 9 May 2013
(No difference)

87.149.142.223 at 07:44, 20 December 2012

2012-12-20T07:44:48Z

New page

#
# SGradation() is a "2nd order gamma" function.
#
# While overall luma and contrast, i.e. levels 0, 128, 255, are not affected,
# SGradation expands or compresses the luma histogram outwards from he center
# (with gamma > 1.0) or towards the center (with gamma < 1.0).
#
# SGradation() allows to soften the visual contrast of images with too much
# contrast. But rather than just reducing all the contrast, SGradation()
# leaves black, medium lightness and white untouched, and just reduces the
# lightness of very light, respectively increases the lightness of dark areas.
# This is useful after recapturing movies if the camera could not cover the
# projection contrast.
#
# On the other hand, the effective contrast of dim pictures can be expanded,
# yet conserving the details in dark and light areas, i.e. not saturating
# and cutting black and white areas, but leaving a soft gradient.
#
#
# Parameters
#
# clip clp
# must be given and is the modified clip.
#
# float gamma
# similar to the well known gamma. Values below 1.0 reduce contrast.
#
# int median
# the luma center point - default 128.
#
# float darkgamma, lightgamma
# allow separate gamma values for the dark/light part of the image.
#
# bool pclevels
# when true, assumes and returns "PC" luma levels.
# (see ColorYUV doc for explanation)
#
#
# output luma with gamma < 1.0
# ^
# 255+ +
# | +
# | +
# | +
# | +
# | +
# | +
# 128+ +++
# | +
# | +
# | +
# | +
# |+
# |+
# 0+-------------+-------------+> input luma
# 0 128 255
#
#
# 04/16/2007 martin53
#
function SGradation(clip clp, val "gamma") {
g=float(default(gamma,1.0))
gc=clp.GreyScale()#.ColorYUV(levels="TV->PC")
dk=gc.Levels(0,1.0/g,127,0,127)
lt=gc.Levels(235,1.0/g,128,107,0,coring=false)
# dk=gc.Levels(127,g,0,127,0)
# lt=gc.Levels(128,g,235,0,107,coring=false)
r=Overlay(dk,lt,mode="add")
r.MergeChroma(clp)#.ColorYUV(levels="PC->TV")
}

Back to [[Shared functions]].
[[Category:Shared_functions]]