selectivecolor

Adjust cyan, magenta, yellow and black (CMYK) to certain ranges of colors (such as "reds", "yellows", "greens", "cyans", ...). The adjustment range is defined by the "purity" of the color (that is, how saturated it already is).

This filter is similar to the Adobe Photoshop Selective Color tool.

The filter accepts the following options:

correction_method

Select color correction method.

Available values are:

‘absolute’

Specified adjustments are applied "as-is" (added/subtracted to original pixel component value).

‘relative’

Specified adjustments are relative to the original component value.

Default is absolute.

reds

Adjustments for red pixels (pixels where the red component is the maximum)

yellows

Adjustments for yellow pixels (pixels where the blue component is the minimum)

greens

Adjustments for green pixels (pixels where the green component is the maximum)

cyans

Adjustments for cyan pixels (pixels where the red component is the minimum)

blues

Adjustments for blue pixels (pixels where the blue component is the maximum)

magentas

Adjustments for magenta pixels (pixels where the green component is the minimum)

whites

Adjustments for white pixels (pixels where all components are greater than 128)

neutrals

Adjustments for all pixels except pure black and pure white

blacks

Adjustments for black pixels (pixels where all components are lesser than 128)

psfile

Specify a Photoshop selective color file (.asv) to import the settings from.

All the adjustment settings (reds, yellows, ...) accept up to 4 space separated floating point adjustment values in the [-1,1] range, respectively to adjust the amount of cyan, magenta, yellow and black for the pixels of its range.

Examples

• Increase cyan by 50% and reduce yellow by 33% in every green areas, and increase magenta by 27% in blue areas:

  selectivecolor=greens=.5 0 -.33 0:blues=0 .27
  

• Use a Photoshop selective color preset:

  selectivecolor=psfile=MySelectiveColorPresets/Misty.asv