Job Gradation Curves
Alters the color output for the entire job
based on a gradation curve. The gradation curve will be applied uniformly
across the entire job and affect all images and colors.
Since Patch Release 17.6.2.0282, every new installation of the Ergosoft RIP now provides several default gradation curves suitable for all color setup types. Similar to Adobe Photoshop's default curves, which operate within the image color space, these default Job Gradation Curves (operating in the output/printer color space) enable you to effortlessly adjust tonal ranges, with a focus on image contrast. The default methods include different levels of contrast, linear contrast, increasing contrast only, and brightening or darkening images. Please note that Job Gradation Curves are processed directly within the color management system (CMS). Therefore, a valid printer profile is required in the Print Environment.
To access Gradation Curves, make sure no
image in the Job is selected, then go to the Properties & Actions Pane on
the right side of the JobComposer Workspace and select Job Gradation Curves.
Note that for this feature, no color
accurate preview is possible; output may look quite different from what is
shown in the Job Preview window.
To define a gradation curve for the Job,
either select -Custom Settings- from the dropdown menu and then click the Edit
button, or click the green + button to create a new gradation curve Preset.
The Gradation Curve
In the Job Gradation Curves window, you’ll
see the channel setting at the top. This defines which color channel you are
altering with the curve. Select the channel you would like to adjust and change
the curve as desired. You can alter all channels together, or each channel
individually. You may also use the All Channels checkbox so the same curve is
applied to all color channels.
The horizontal axis represents the
theoretical channel density. Think of this as the input density, i.e. the
density for a channel that is defined in the file. The bottom left corner is
zero or no density; the bottom right corner is the full or maximum density for
the channel.
The vertical axis represents the output
density of the channel. The bottom right corner is zero or no density; the top
right corner is the maximum density.
Using this graph lets us map an input
density value to an output density, affecting the ink output in that channel.
An easy example would be if we notice that a color channel applies too much
ink. By adjusting the vertical endpoint to a lower value, e.g. 70%, we specify
that the maximum available density (100% on the input/horizontal axis) may not
exceed 70% of the vertical axis. This maps 100% input density to 70% output
density, effectively limiting the density of the white channel to 70%, decreasing
ink application linearly as a result.
In the above example, we keep the ink
application linear so the rise of the input density still directly corresponds
to the rise of the output density, but we cap the maximum output density to 70%, meaning that we can reduce the maximum of one ink channel that is applied.
This helps you to control ink application
and push the contrast of your image by ensuring that the peak values of a color
match the maximum applied by the profile.
The gradation curve also lets you specify
additional points in the curve itself by clicking any point on the line and
dragging it to the desired point. This allows for complex adjustments and
non-linear density gain to match and customize printer and ink behavior.
Auto: At the bottom of the dialog, you'll
also find an Auto Button. This will use internal calculations based on the
profile in the Print Environment to create the optimal maximum value for the
Job Gradation Curve. In practice, this will yield better color dynamics,
contrast and saturation for your job output. The example below shows automatic
job gradation applied to the orange channel of the image:
No Auto Job Gradation Correction With Auto Job Gradation in Orange Channel
You can also see a video representation of the effects of Job Gradation Curves in this video on our YouTube channel.
Once you have made the desired adjustments, confirm with Ok to save your curve or Cancel to discard your changes. After adjusting the curve, remember to click Apply in Properties & Actions > Job Gradation Curve to apply your modified curve to the Job itself.