(펌)포토샵 블렌드 모드 공식

출처  http://www.deepskycolors.com/archive/2010/04/21/formulas-for-Photoshop-blending-modes.html

Blend mode	Commutativity	Formula	Addtl .info
Darken	commutative	min(Target,Blend)
Multiply	commutative	Target * Blend
Color Burn	non-commutative	1 - (1-Target) / Blend
Linear Burn	commutative	Target + Blend - 1
Lighten	commutative	max(Target,Blend)
Screen	commutative	1 - (1-Target) * (1-Blend)
Color Dodge	non-commutative	Target / (1-Blend)
Linear Dodge	commutative	Target + Blend
Overlay	non-commutative	(Target > 0.5) * (1 - (1-2*(Target-0.5)) * (1-Blend)) + (Target <= 0.5) * ((2*Target) * Blend)	A combination of multiply and screen.Also the same as Hard Light commuted
Soft Light	non-commutative	(Blend > 0.5) * (1 - (1-Target) * (1-(Blend-0.5))) + (Blend <= 0.5) * (Target * (Blend+0.5))	A combination of multiply and screen(The formula is only approximate)
Hard Light	non-commutative	(Blend > 0.5) * (1 - (1-Target) * (1-2*(Blend-0.5))) + (Blend <= 0.5) * (Target * (2*Blend))	A combination of multiply and screen. Also the same as Overlay commuted
Vivid Light	non-commutative	(Blend > 0.5) * (1 - (1-Target) / (2*(Blend-0.5))) + (Blend <= 0.5) * (Target / (1-2*Blend))	A combination of color burn and color dodge
Linear Light	non-commutative	(Blend > 0.5) * (Target + 2*(Blend-0.5)) +  (Blend <= 0.5) * (Target + 2*Blend - 1)	A combination of linear burn and linear dodge
Pin Light	non-commutative	(Blend > 0.5) * (max(Target,2*(Blend-0.5))) +  (Blend <= 0.5) * (min(Target,2*Blend)))	A combination of darken and lighten
Difference	commutative	| Target - Blend |
Exclusion	commutative	0.5 - 2*(Target-0.5)*(Blend-0.5)