SelectiveColour

Latest revision as of 11:46, 9 February 2023

[edit] Description

SelectiveColour - AviSynth implementation of Photoshop's selective colour adjustment.

[edit] Requirements

• [x86]: AviSynth+ or AviSynth 2.5.8 or greater
• [x64]: AviSynth+
• Supported color formats: RGB32

[edit] Syntax and Parameters

selectivecolour (clip, float, float, float, float, float, float, float, float, float, float, float, float, float, float, float, float, float, float, bool)

clip   =

Input clip; must be RGB32.

float   =

This filter partially copies the actions of Photoshop's "Selective colour" image adjustment action. Apart from an input clip it takes 19 arguments.

The first 18 are floats in the range -1 to 1 (other values are accepted, but that behaviour is not well defined).

These are in groups of three, representing the Cyan, Magenta, and Yellow %ages (normalized) present in Photoshop's Selective Color dialogue for each of the six colour sections (reds, yellows, greens, cyans, blues, magentas).

bool   =

Boolean to choose either relative (false) or absolute (true) mode, as per the Photoshop dialogue box.

Note: all parameters are unnamed and do not have a default so they must be specified.

[edit] Examples

Usage:

AviSource("blah.avi")
ConvertToRGB32()
selectivecolour(last,\
0.5,0,0,\
0.25,0.1,0,\
1,-0.5,-0.25,\
-0.5,0.5,-0.5,\
0.1,0.2,0.3,\
-0.1,-0.2,-0.3,\
true)

The six triples act on the following sets of pixels (a pixel may be a member of up to 2 adjacent sets):

• Reds: those pixels where R>G and B
• Yellows: R and G>B
• Greens: G>R and B
• Cyans: G and B>R
• Blues: B>R and G
• Magentas: R and B>G

The first number in a triple alters the Red channel, the second the Green channel, the third the Blue channel. Because Photoshop calls these values Cyan, Magenta and Yellow, the numbers work backwards - if you want to increase the intensity of a channel, use a negative number, and vice versa.

The filter doesn't currently implement the "Black" value in Photoshop.

[edit] Changelog

Version      Date            Changes

             2020/07/20      - Add x64 version.
             2011/10/08      - The filter's now written a bit better, doesn't 
                               suffer from pitch problems, and is multithreaded.
             2009/12/10      - Initial release.

[edit] Archived Downloads

• Source code (2011/10/08 )

[edit] External Links

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