In this article, you will learn
- what a Color Correction is and
- what options for Color Corrections are available in the Workflow.
1. Introduction
Users may sometimes want to perform a Color Correction to change the contrast or achieve a slight color correction. Such corrections are applied with regard to saturation, color angle or tonal value and are used for output on the printer. Color Corrections can be applied either directly to the Print Item itself or when rendering the Production Job on the printer.
2. Apply Color Corrections to Print Items
To apply Color Corrections to Print Items, use the following Fixups in your Workflow:
- CMYK Color Correction – apply a freely definable correction curve to CMYK colors.
- Redye CMYK Objects – change existing CMYK color values.
- Convert Grayscale into CMYK – convert objects that are in grayscale to the black channel of CMYK.
- Convert to Grayscale – convert the selected object types to grayscale.
- Increase Tonal Values in Midtones – lighten the Print Item based on a freely definable correction curve.
- Reduce Tonal Values in Midtones – darken the Print Item based on a freely definable correction curve.
CMYK Items Only?
A Color Correction applied to a Print Item via a Fixup will only affect CMYK items. Spot Colors and RGB items can be included in the conversion if they are first converted to CMYK. This option is offered explicitly in some Fixups.
To apply a Color Correction specifically to a Spot Color, do this either via the Define and Edit Spot Colors dialog or via the Rename, Convert or Remove Spot Colors Fixup. Please note, however, that a change to a Spot Color definition is not applied directly to the Print Item, but only when rendering.
3. Apply Color Corrections when Rendering
Color Corrections have to be available as DeviceLink Color Correction Profiles for rendering and thus have to be created before the render call. The following options are available in the Workflow to apply a Color Correction based on DeviceLink profiles during rendering:
- Image-based Color Corrections A Color Correction can be performed on a reference image in an external image editing program and then uploaded back into the Workflow. The Color Correction stored in a DeviceLink can be selected in the Output Template in the DeviceN Color Correction area and applied to the Production Job.
- Curve-based Color Corrections The Color Correction can be saved and applied by specifying values based on a correction curve for a specific Printer or Print Configuration. The Color Correction saved in a DeviceLink can be selected in the DeviceN Color Correction area in the Output Template and applied to the Production Job. The DeviceN Color Correction drop-down menu offers a selection of the supplied Color Corrections.
- Color Correction in the Production Job The Color Correction can be specified by entering the percentage values for the 50% and 100% tonal value of the respective CMYK channel. This Color Correction, stored in a DeviceLink, is applied after the other selected Color Corrections in the Output Template.
Color Spaces Included in Color Correction
Generally, only CMYK objects are affected by the correction when rendering, depending on which color correction option you have chosen. RGB, grayscale, and LAB objects are already converted to CMYK when rendering, which is why these color spaces are also included in the color correction.
Only Spot Colors can be prevented from being fixed or included in the Fixup, depending on the selected Fixup. A modified Spot Color definition is always applied during rendering, regardless of the selected Fixup.
DeviceLink Color Correction Profiles
Because the Workflow supports open standards, DeviceLink profiles created in image-based or curve-based Color Corrections can be downloaded and used in Photoshop or another application that supports DeviceLink profiles.
Artikel update: Workflow Version 1.19.0 – 01/2025