In this article, you will learn
- which prerequisites are required for this Fixup, and
- how to apply this Fixup.
1. Introduction
The Fixup CMYK Color Correctionis available in the Workflow. The purpose of this Fixup is to correct the CMYK color values based on the correction curves of the individual color channels.
2. General
The Fixup CMYK Color Correction can be used to correct individual color channels. Spot Colors and RGB color values can also be corrected if they are converted to CMYK beforehand.
You can find this Fixup on the tab Data Preparation of an Article, Order or Production Job by:
- entering the name of the Fixup in the area Filter,
- activating the option Color in the area Category,
- activating the option Apply in the area Action,
- activating the option Images, Vectors, or Text in the area Property.
3. Description
With this Fixup individual CMYK color channels can be corrected. If RGB objects and Spot Colors are also to be corrected, you must activate the corresponding options. The Spot Colors and RGB data are converted to CMYK beforehand.
3.1. Prerequisites and Functionality
For the Fixup to perform as intended, no special requirements must be met:
Figure 1: The dialog CMYK Color Correction
Use the following options to color-correct an entire Print Item:
- Templates [1] – settings selected in the dialog can be saved as a template and applied to other Articles/Print Items, as well as used within Fixup Chains and in the Operations Apply Fixups and Check Print Item and Apply Fixups.
- Apply to [2] – select the object types to which the color correction should be applied in the selection menu. The following options are available in the selection menu:
- All Objects – all object types are color-corrected.
- Images only – only images are color-corrected.
- Vector only – only vectors are color-corrected.
- Text only – only texts are color-corrected.
- Text and Vector – only texts and vectors are color-corrected.
- Variable Content [5] – for Variable Content [5] , select the desired placeholder – Database Field or User-defined Field – from which the value for the respective objects should be retrieved. The following values must be present in the selected field so that the selection is executed:
Is_AllIs_ImageIs_VectorIs_TextIs_Vector_Text
Figure 2: Values for the option Apply to
- Convert Spot Color Objects to CMYK [3] – by activating the function, all Spot Colors are converted to CMYK before the actual color correction. The CMYK color correction is then also applied to the converted Spot Colors.
- Convert RGB Objects to CMYK [6] – by activating the function, all RGB objects are converted to CMYK before the colors are corrected.
- Dot Gain Curve [4] – the curve of the respective color channel is displayed in the preview image. The desired color channel can be selected for illustration in the selection menu [7].
- Show all Channels [8] – all channels are displayed by activating the function.
- Output [9]– enter the output color value to be corrected for the input color value.
- Apply current values to all Channels [10] – pressing the button transfers the values of the current curve to all color channels.
- Add [11] – insert a new point in the curve, allowing you to add the corresponding corrected output color value to a new input color value.
- Linear Curve / Bezier Curve [12] – determine whether the curve should only consist of corner points or whether the curve should be made up of Bezier curves.
3.2. Before/After
To experiment with this Fixup, use the sample file "Sample_Farbkorrektur.pdf". The sample file has a size of 500 x 500 mm and a Bleed of 3 mm. The file was partially created in CMYK, in RGB as well as with Spot Colors.
After applying the Fixup, the file "Sample_Farbkorrektur_End.pdf" is created. All RGB objects were converted to CMYK with the Fixup. The tone value curve was edited to create a high contrast.
Figure 3: Left: Initial file; Right: Edited file in which the contrast of the colors was increased
Article update: Workflow 1.20.0 – 03/2025