"Color Management" tab

In this tab, you set how device-independent colors will be handled and matched to the target color spaces.

"Device independent Colors" group

In the characterization of a digital image recording device, for example, a digital camera, the device-specific properties are captured as a set of characterization curves. There are standardized templates and measuring processes for this that vary according to the device used. The characterization curves are evaluated and converted with a special software. The result is a device-dependent RGB ICC pro­file. When such an ICC profile is embedded to a document, it can be used as an "input ICC profile". Through this profile, the RGB data of the device are transformed into the CIEL*a*b* color space. These transformed image data are now "device-independent". The following types of objects exist:

•CMYK/grayscale images

•CMYK/grayscale graphics

•RGB/L*a*b* images

•RGB/L*a*b* graphics

•Spot Color Images

•Spot Color Graphics

The "L*a*b*", "CalibratedRGB" and "CalibratedGray" color spaces as well as the objects defined in these color spaces are device-independent as they are uniquely identified.

"Treat ICCBased CMYK as Device CMYK" option

The profiles defined by the print buyer are removed if this option is checked. The documents are now printed without color transformation. In the "Device Colors/DeviceLink" tab, however, you can set a different CMYK profile as the input profile for color space transformation. This procedure is advisable if the print buyer has used unsuitable profiles.

The embedded ICC profiles are used for conversion to the target color space. In other words, there is a "CMYK -> CMYK conversion".

"Treat ICCBased RGB and Calibrated RGB as Device RGB" option

All embedded RGB ICC profiles are removed from the document files if this option is checked. This means: the documents in the device-independent RGB color space are treated as device-dependent documents in the "DeviceRGB" color space with the appropriate settings.

Colors from the device-independent "CalRGB" color space are converted to the device-dependent "DeviceRGB" color space without color management. Afterwards, the colors are converted to the tar­get color space using color management with the ICC profiles set in "RGB Image" or "RGB Graphic" in the "Device Colors/DeviceLink" tab. See "Device Colors/DeviceLink" tab.

The embedded ICC profiles are used for conversion to the target color space or colors from "CalRGB" are treated as "sRGB" in compliance with the PDF specification and converted to the target color space if this option is not checked.

"Treat ICCBased Gray and Calibrated Gray as Device Gray" option

All embedded Gray ICC profiles are removed from the document files if this option is checked. This means: the documents in the device-independent CalGray color space are treated as device-depen­dent documents in the "DeviceGray" color space with the appropriate settings.

The color is used in the K separation. This setting prevents a "chromatic" gray.

The embedded ICC profiles are used for conversion to the target color space or colors from "CalGray" are converted to the target color space in compliance with the PDF specification if this option is not checked. Remember that the color then contains CMY.

Rendering Intent

In addition to selecting ICC profiles, you can set the rendering intent for the individual graphics/image types. Rendering intent determines how color matching ("gamut mapping") is done. Since losses always occur during a color space transformation, it can be helpful, for example, to retain the photo­graphic perception of a master as true as possible to the original and to accept a limit on the number of color values.

The following parameters are available for rendering intent: "From Document", "Absolute Colorimet­ric", "Relative Colorimetric", "Saturation" and "Perceptual".

•From Document

The Color Rendering Intents that were defined for images and graphics in the PDF documents are used.

Note: You should select "from document" only if you are absolutely sure that the edited documents have a rendering intent setting that can correctly control the color space con­version desired. However, you should not use this setting if at all possible because this is very seldom the case.

•Saturation:

In the output, the colors are rendered in such a manner that the color saturation is retained or even emphasized. The type of color matching is manufacturer-specific, with the user being able to define some settings during profile generation. This option is suitable for business graphics where the color saturation is the most important attribute in color rendering.

•Perceptual:

When you use the "Perceptual" parameter, you obtain an output, that essentially contains the perceptible impression of the original. This means that the precise, colorimetric rendering of the colors is modified in favor of the retention of the relative color relationships. In a smaller target color space, the color gamut is compressed accordingly. Vice versa, in a larger target color space and with suitable profiles, the color space may be expanded. With this color matching option, the hue in all the natural colors of the original is reproduced for the most part correctly but with restrictions in the contrast. The type of color matching is manufacturer-specific, with the user being able to set some of the aspects such as contrast and chroma change during profile gener­ation. This option is especially suitable for photographs.

•Relative colorimetric:

Colors are rendered taking solely the light source into account. The rendering intent of the print medium (e.g. the color of the unprinted paper) is not taken into account. For example, the illu­minant of a monitor would be correctly rendered on the print medium. That is why the term "rel­ative" is used. All colors that lie within the output color space are rendered identically. All colors that lie outside of the target color space are displayed on the margin of the target color space. That is why the term "colorimetric" is used.

The advantage of this rendering intent is that different white points of various output media are taken into account. The disadvantage is that the color adaptations are not exactly retained when switching from one output medium to another. As a result, very dark or very colorful details in the originals can be lost when they are reproduced. The printing material is not simulated during an output process simulation. If production run paper is used during the simulation, the result is the same as if you used the "absolute colorimetric" rendering intent. This rendering intent is suitable mainly for vector graphics.

•Absolute colorimetric:

Colors are rendered taking the light source and the medium illuminant (e.g. the color of the unprinted paper). For example, the illuminant of a newsprint paper which is shifted towards yel­low compared to the illuminant of illustration printing paper is rendered with a yellowish cast. That is why the term "absolute" is used. That is why "Absolute colorimetric" is the default setting for a proof output. All colors that lie outside of the output color space are displayed on the mar­gin of the output color space.

The advantage of this rendering intent is that the exact color values are retained when switching from one output medium to another. The disadvantage is that any colors that lie outside of the output color space cannot be distinguished. This rendering intent is especially suitable for logos or monochrome objects which must be reproduced exactly the same way on different output media. You can set a separate rendering intent for spot colors that is independent of the color space of the alternative display color. "Absolute colorimetric" is recommended. This makes sure that the spot colors are simulated as best as possible.

"BPC" option

Black point compensation (BPC) becomes active if you enable the "BPC" option. You can enable black point compensation (BPC) for "Relative Colorimetric" "Perceptual" and "Saturation" rendering intents. However, the effect of this option can only be seen for the rendering intent "Relative Colori­metric".

In gamut mapping, all L shadows (in the L*a*b* color space) that are darker than black toner/ink are matched to black toner/ink and, as a result, shadow definition is lost.

Black point compensation is similar to Photoshop's "Use Black Point Compensation" option.

Black point compensation enhances the reproduction area when the "Relative colorimetric" render­ing intent is used for color space conversion to the L*a*b* color space or from the L*a*b* color space to the device color space. The L*a*b* color space has more lightness levels for dark image parts than the CMYK color space because the L*a*b* color space is larger than the CMYK device color space. In a color space conversion from the L*a*b* to the CMYK color space with "Relative Colorimetric" rendering intent, the color space is cut off or reproduced without definition in the shadows because they are located outside the displayable range. As a result, details in dark parts of the image are often lost, especially if ICC profiles for uncoated papers are used for color space conversion.

Black point compensation matches the black point during color space conversion, causing the defi­nition in such dark image parts to be kept. This "elongates" the shadows causing color shifts to occur also in the lighter color values. For that reason, this method is not always suited to true-color proof­ing.

We recommend that you use "Perceptual" rendering intent with black point compensation and not "Relative Colorimetric" rendering intent. This rendering intent makes it possible for the various details in dark image parts to be reproduced, while keeping color shifts to a minimum. In principle, differ­ences cannot be fully avoided because of the different sizes of the color spaces.

"Output" Group

In this group you define an ICC profile for transformation of the color space to the target color space of the printing process and set the related options.

"Press Profile" box

This is where you set a color profile for the output process or the printing press used. You can cus­tomize your printing process, e.g. to regionally specific printing processes (SWOP, EURO, etc.), by selecting a suitable profile.

You can assign the press profiles to different target color spaces depending on your output:

•Normally you use a "DeviceCMYK" profile for presses.

•You can also set multicolor profiles like PANTONE® Hexachrome, Hifi Color, etc.

•You can use a "DeviceGray" profile for a black-and-white output.

•You can use a "DeviceRGB" profile for a monitor output (e.g. a page in the web). However, RGB color spaces in the job settings of the Prinect Manager ("Colors" section) cannot be displayed.

Click "Browse..." to open a dialog where you can select a suitable press profile.

Note: You will find an overview of all the ICC profiles available in the Prinect system in "Administration" > "Resources" > "ICC Profiles". You can also import new profiles, create new profile folders, delete profiles, etc. there. The ICC profiles are filed in "SysCon­fig\Resources\ICC Profiles". "SysConfig" is the shared configuration folder on the Prinect server.

"Use Press Profile from Job Settings, if Available" option

An output press profile that was assigned to the job in the job settings in the "Colors" or "Printing Pro­cess" section is used if this option is enabled.

In the job settings you can check in "Consistency Check" in the "Printing Process" group whether a press profile that you will assign to the job is suitable for this purpose.

•If there is a green dot in front of the selected press profile, you can process the job with the selected press profile.

•There is a conflict if there is a yellow triangle before the selected press profile. If this is the case, you should use a different press profile.

"Use PDF/X Output Intent, if available, as Press Profile" option

•The Prinect Manager behaves as follows if this option is enabled:

When a PDF/X file with an embedded ICC profile as its Output Intent is processed, the embed­ded press profile is used for color space conversion. The press profile set in "Press Profile" is ignored.

If there is no Output Intent, the ICC profile set in "Press Profile" will be used.

•The press profile set in "Press Profile" is used for color space conversion if this option is not checked.

Any embedded PDF/X Output Intent will not be used for color space conversion during output.

If you wish to process jobs in the Prinect workflow using the PDF/X policies, you must always enable this option.

"Embed Applied Press Profile as PDF/X Output Intent" option

The used press profile is embedded in the PDF file as the PDF/X Output Intent if this option is checked. The embedded ICC profile specified as the Output Intent replaces the profile set in "Press Profile" and is used for output if the "Use Embedded PDF/X Output Intent, if Available, as Press Pro­file" option is also checked and there is a PDF/X Output Intent in the processed PDF/X file. In addi­tion, this embedded profile will be embedded as the new Output Intent during export. This option can be good policy for data interchange.

In all other cases, the profile set in "Press Profile" is embedded in the PDF file as the PDF/X Output Intent.

The set press profile is not embedded in the PDF file as the PDF/X Output Intent if this option is not checked.

"Use PDF/X Output Intent, if Available, as CMYK Input Profile" option

If you enabled this option, a PDF/X file with a defined Output Intent and embedded ICC profile is always used as the input profile for CMYK images and CMYK graphics if you are going to process such a file. The ICC profiles set for this purpose in the "Device Colors/Device Link" tab will be ignored.