10.3.5. Process

If all required settings in source image and reference values are ready you can move to the process tab.

You first need to tell darktable-chart which of the patches represent the gray ramp. In the screenshot displayed further above the gray ramp is positioned in the lower part of the color reference chart, denoted as GS00...GS23.

The input number of final patches defines how many editable color patches the resulting style will use within the color look up table module (for more details see Section 3.4.3.6, “Color look up table”).

By clicking the process button you start the calculation.

The quality of the result in terms of average delta E and maximum delta E are displayed below the button. These data show how close the resulting style applied to the source image will be able to match the reference values – the lower the better.

Once you are happy with the result you can click on export and save the generated style.

You supply a style name and a style description under which the style will later appear in darktable. darktable-chart saves the style as a .dtstyle file which can be imported into darktable (see Section 2.3.8, “Styles”) and shared with others.

The export raw data as csv button allows you to save the extracted raw data as a CSV file for debugging purposes or later usage. darktable-chart offers a command line option to produce a style with the desired number of final patches from a supplied CSV file (see Section 1.1.4, “darktable-chart binary”).