Adjusting tone values

Adjusting tone values

Besides the ICC based color conversion it is possible to adjust the tone values in a PDF file. This can be performed with a different configuration file, called curvefile.

Syntax of a curve file

The curve file needs to be a tab delimited text file with the suffix ".crv" structured as following:

DisplayName 1 Example 

INPUT DEFAULT Cyan Magenta Yellow Black REGEX::.*Pantone.* 

0.0 0.0 0.0 0.0 0.0 0.0 0.0
0.1 0.1 0.1 0.12 0.1 0.1 0.11
0.2 0.3 0.3 0.3 0.3 0.3 0.3
0.3 0.4 0.4 0.4 0.44 0.4 0.42
0.4 0.5 0.5 0.52 0.5 0.45 0.5
0.5 0.6 0.6 0.6 0.6 0.6 0.6
0.6 0.7 0.7 0.7 0.7 0.66 0.68
0.7 0.79 0.8 0.8 0.8 0.76 0.78
0.8 0.85 0.85 0.86 0.85 0.8 0.82
0.9 0.9 0.9 0.9 0.92 0.9 0.91
1.0 1.0 1.0 1.0 1.0 1.0 1.0 

Not all values have to be listed in this file. For intermediate values not present a spline based interpolation is used.

Besides adjusting the tone values for each CMYK separation, you could also use the column title "All" to adjust all separations to the same value or "RGB::Red", "RGB::Green" and "RGB::Blue" for RGB as well as "LAB::L" for Lab color spaces. Every other column title will be considered as a spot color name. In order to be able to address a group of spot color channels regular expressions are supported as follows: "REGEX::_some_regular_expression_".

Using curve files

 

Set up a new Fixup using an own curve file, select "Create Fixup" in the list of all FIxups. Search for "Adjust dot gain".

Set up a curve file as described above and copy it into the respective directory (depending on current used LIbrary), which can be opened using the entry "Open folder with configuration files" in the pop-up menu "Dor gain curve setting":

Copy your curvefile into the opened folder.
After closing and reopening the Fixup, the new dot gain curve setting can be selected.

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