ImageServer G8 User manual (Version 6.0.0)  

4 Set up ImageServer with HELIOS Admin

The following chapters explain OPI related dialogs. For an overall description of the HELIOS Admin program, please refer to the HELIOS Base manual.

The HELIOS Admin program lets you specify various parameters that are required for using OPI. However, some specific parameters can be set or changed manually using command line commands. For advice on how to handle these commands, please refer to the reference guide in this manual (see 6 “ImageServer utility programs”).


You may not skip the administration before using OPI because, by default, OPI is not active on printer queues and color matching has to be activated explicitly as well.


The following chapters describe the effects single settings will have. In Appendix A “About OPI settings, typical workflows, and conflicts” you can see how different settings influence one another and how the software behaves if application specific OPI settings intervene.

4.1 ImageServer settings

The “ImageServer Settings” dialog contains three tabs in which you can define general OPI settings. These are valid for all layout images that are generated by the server, unless overridden by folder specific or command line settings.


Select Settings > ImageServer Settings from the HELIOS Admin menu to open the OPI Color tab (Fig. 4.1).

Defining <code>OPI Color</code> preferences

Fig. 4.1: Defining OPI Color preferences


The Revert and Apply buttons remain disabled until you apply changes in the dialog.

ICC Profile Volume

Color matching with ImageServer is based on ICC profiles. All profiles that you want to use must be stored in a central repository. Setting up ICC Profile Volume tells the server where to find the profiles.

A pull-down menu shows by default the entry ICC-Profiles. It lets you select the volume “ICC-Profiles” that has automatically been created during the software installation. This volume contains all the profiles we have included in our software package.

The Browse... button is used to select the current profile repository (in case it is not the “ICC-Profiles” volume).

Layout Color

This item serves to select a color space for all layout files that are generated on the server, and at the same time defines an ICC profile which is used for color matching the layouts.

You can choose a profile via the Browse... button, or select one of the four predefined profiles from the pop-up menu:

Default CMYK Color

The CMYK default profile is used whenever OPI has to transform an image from another color space into CMYK or vice versa and if – in a situation like that – a CMYK output (printer) or source (image) profile has not explicitly been defined. If you e.g. select sRGB IEC61966-2-1 from the Layout Color menu and your high-resolution image is a CMYK image, OPI has to perform a transformation from CMYK into RGB during layout generation. If your high-resolution original has no source profile, OPI will use the CMYK Default Profile. The pull-down menu lets you select either SWOP or Euro.

Defining <code>OPI Layout</code> preferences

Fig. 4.2: Defining OPI Layout preferences


Open the OPI Layout tab (Fig. 4.2).

Layout Quality

The quality of the generated image may be either Excellent or Standard.

Layout Compression

Layout images do not inherit any compression from the high-resolution originals. You may choose a compression mode, though. There are three possible options which can be – even more than one concurrently – selected from the checkboxes:

Clipping paths
Additional channels
Default Monitor Resolution

This item serves to define the default monitor resolution for your layout files. Monitor resolutions usually have a range between 72 and 200 dpi.

Default Print Resolution

EPSF files contain a monitor preview and a printable preview of the respective image. It is therefore sensible to allow you to define for your layout images two different dpi values. You can e.g. enter 72 dpi monitor resolution and 96 dpi print resolution if you print your documents with EPSF layout images and want to achieve a printout quality better than 72 dpi.


For files that have only one preview (for printing and monitor display) the OPI software compares the Default Monitor Resolution to the Default Print Resolution and uses the higher value as layout resolution. This applies e.g. to TIFF images.

Layout Delay

In this field you may define the time in seconds before the layout creation process is started by the OPI server. The purpose is to prevent layout file generation from temporary files or files that are in use.


Please note that all above mentioned server settings are only applied to future layout files. If you want to update any existing layouts, you must re-generate them. For that purpose you can either open and save the high-resolution original image file once again, use the HELIOS “touch” program (see 5.5 “Refresh layouts using the “touch” program”), or use the “opitouch” program (see 6.2 “opitouch”).


Open the Image Search Paths tab (Fig. 4.3).

Defining <code>Image Search Paths</code> preferences

Fig. 4.3: Defining Image Search Paths preferences

Image Search Paths

In some situations you may want to move your image files to another volume or folder. You can help OPI find these images for printing if you define search paths that lead to the locations you usually use.

There are, in principle, no limits as far as the number of search paths is concerned. However, you can save time if you make sure that the locations you use frequently are checked first.
Please note that no subdirectories are searched for images.

The “Server Settings” window shows the image search paths that are already defined. You can delete any of these paths or add new ones. The Add... button opens the dialog that serves to select new paths (Fig. 4.4).

Defining image search paths

Fig. 4.4: Defining image search paths


Detailed explanations on how ImageServer deals with image search paths are given in 3.7 “How ImageServer finds and replaces image files”.

4.2 Volume settings

Some OPI settings are volume-dependent. To edit the settings for a specific volume do the following:


In HELIOS Admin open the Volumes tab and highlight the volume you wish to configure. Then open the volume settings and select the OPI tab (Fig. 4.5).

Defining volume-dependent OPI settings

Fig. 4.5: Defining volume-dependent OPI settings

Create Layouts

This option controls the automatic generation of layout files. Create Layouts will make the OPI server generate a low-resolution layout file of each image file you save to this volume. The generation of layouts will take a few moments, it starts after a user-defined time delay. By default this is a delay of 30 seconds (see Layout Delay above in this chapter).


When copying OS X packages, e.g. application packages or RTFD documents, to a HELIOS volume with automatic layout generation active, layouts of all images within the package will be generated. Though this will not corrupt the package it can considerably enlarge the package size.

PC Layouts

File characteristics are slightly different on Mac and Windows computers. Switch PC Layouts on if you want OPI to always generate PC-compatible layouts – even if the original high-resolution images are coming from a Mac computer; OPI generates layout files always according to the PC Layouts checkbox in the HELIOS Admin volume settings (Fig. 4.5).


Since the Mac is also able to recognize PC-compatible layouts, make sure to always have checked the PC Layouts checkbox when working in a volume shared with PCShare (see also appendix F “Notes for PCShare users”).

Please note that working with PC Layouts would mean that if OPI generates EPSF layouts, these layouts will be PC-EPSF files with TIFF previews (instead of PICT previews).

4.3 OPI printer queue settings

Some OPI settings are only meant for printing, and have to be set up for every single printer queue.


It may be helpful to define an “Error Queue” for your OPI printer queue. This allows you to save print jobs that have produced an error message (e.g. because of missing image files). After solving the problem, the print jobs can be started again directly from the error queue. For details refer to the HELIOS Base manual.


Highlight a printer from the Printers list and then select Printer > Settings from the HELIOS Admin menu and go to the OPI tab to open the dialog shown in Fig. 4.6.

Defining OPI settings for a printer queue

Fig. 4.6: Defining OPI settings for a printer queue

OPI Active

The OPI Active option enables OPI for this specific printer queue, and at the same time activates the “OPI Printer Setup” section.

Print Layout Images

With Print Layout Images enabled, printouts from this specific printer queue will only contain layout images. The print job will be sent to the OPI server where the OPI comments of the placed layouts are resolved, but no image replacement is performed.

Replace Images

Replace Images = Layouts is the default resolve option. If this setting is active, the OPI server will only replace layout images during printing. High-resolution originals you may have placed in your document, will not be replaced. In case you want the OPI server to replace all images during printing (e.g. if you want to use the “Omit …” options print dialog) you should switch to Replace Images = All (see also 5.6 “OPI print options – Printing from QuarkXPress and InDesign”).

Check Images

The Check Images option will induce ImageServer to stop the print job and issue an error message if the current print job contains any images that are not available. The strategies the OPI server uses for locating images are described in 3.7 “How ImageServer finds and replaces image files”. If Check Images is not active, single images may be missing in the printouts.

Check Fonts

The Check Fonts option will induce ImageServer to stop the print job and issue an error message if the current print job contains any fonts that are not available.


The Downsampling item serves to define a uniform output resolution for all raster-based images – no matter whether you print layout images or high-resolution originals. If the resolution of a given image is higher than the value in this dialog (144 dpi in Fig. 4.6), the OPI server will apply the value you have chosen for downsampling and then re-calculate and scale the image accordingly. Images with a resolution smaller than the value entered in this dialog, will remain unchanged because increasing the resolution automatically decreases the dimensions of an image. This would entail upward scaling and lead to a loss in quality.

The Downsampling pull-down menu contains a number of dpi values and the PPD Default option. If you select PPD Default, ImageServer will use the resolution that is stated in the PPD file. You may also specify a custom value for downsampling from the pop-up menu. Selecting None from the list will switch downsampling off. Every image will then be printed according to its particular resolution.

PostScript Output Compression

There are efficient compression methods you can apply to the high-resolution images. Depending on the image format there are different types of compression that can be selected from the following pull-down menus. This considerably reduces the size of the PostScript printing data:

For “bitmap color mode” (bilevel) images, the CCITT Group 4 compression is a very good lossless linework compression. It can easily reduce linework file sizes by the factor of 50. It can be used with PostScript Level 2 or higher printers.

The ZIP compression, which is compatible with PostScript 3 compatible printers, is the best lossless continuous tone compression. Compress works with PostScript 2 and 3 and has good compression results. JPEG (Low Quality, Medium Quality, High Quality, Maximum Quality) compression will always lose some image details but offers the best data reduction, it is supported with PostScript Level 2 or higher.

4.4 ICC printer settings


Highlight a printer from the Printers list and then select Printer > Settings from the HELIOS Admin menu and go to the ICC tab to open the dialog shown in Fig. 4.7.

Defining ICC settings for a printer queue

Fig. 4.7: Defining ICC settings for a printer queue

Check ICC Profiles for Pictures

Activating Check ICC Profiles for Pictures (the Check Images OPI option must be activated, otherwise this option has no effect!) induces the OPI server to check whether all image profiles that have been tagged to any of the image files are available. The server will automatically stop the print job if a single profile is missing and issue a corresponding error message. If this option is not active, OPI will execute all print jobs and use standard profiles for color matching, whenever the correct profile is missing, unless the input color space is the same as the output color space, e.g. Image CMYK = Printer CMYK.


Grayscale images without ICC profile information remain unaltered. Grayscale images with profile information are matched to the printer profile (e.g. CMYK). Grayscale images are ignored by the Check ICC Profile for Images option.

Default Printer Profile

The Default Printer Profile item lets you choose the correct profile for your output device and, at the same time, serves to switch on color matching for this printer queue. The pull-down menu contains four different options.

The Browse... button opens a dialog that lets you select a specific profile.

Default Proof Profile

This item becomes only available if you have selected a default printer profile. Here, you can select the correct profile for your proof printer.

Default DeviceLink Profile

This pop-up menu allows you to specify a default DeviceLink profile for color matching. DeviceLink profiles have a higher priority than standard ICC profiles, i.e. standard ICC profiles are overridden by DeviceLink profiles. If a CMYK DeviceLink profile is specified, all CMYK images are converted using this profile. If CMYK images have a tagged profile it will be ignored and the DeviceLink profile is used instead.

Preserve Raster Colors

Exclude White, Black, Gray or CMY colored raster objects from color transformation, so that they preserve the selected color(s), even if color matching is done. For example, gray raster image pixels in arbitrary color space are detected and converted to Gray only for CMYK output, if the Gray option is checked.

Preserve Vector Colors

Exclude White, Black, Gray or CMY colored vector objects from color transformation, so that they preserve the selected color(s), even if color matching is done. For example, gray text and other gray vector objects in arbitrary color space are detected and converted to Gray only for CMYK output, if the Gray option is checked.

PDF Transparency

This option is PDF related and hence described in the HELIOS PDF HandShake manual.

PostScript 3/DeviceN

The PostScript 3/DeviceN Output checkbox should only be selected if you print to a PostScript 3 device with in-RIP separation. The PostScript output of the original files will be optimized to use the PostScript 3/DeviceN features. This applies to Hexachrome printing, colorized images (Duotone), etc. DCS-2, TIFF, PDF, and Photoshop native files containing spot colors are converted into DeviceN. When printing host-based separations with applications like QuarkXPress, this feature must be turned off, otherwise the output will lead to unexpected results.

ICC Intents

This feature offers different “strategies” for rendering an image file from one color space to another. The following settings are available:

1) Automatic
2) Perceptual
3) Relative Colorimetric
4) Saturation
5) Absolute Colorimetric
6) Perceptual with BPC1
7) Relative Colorimetric with BPC
8) Saturation with BPC
9) Perceptual with Black Plane Compensation
10) Relative Colorimetric with Black Plane Compensation
11) Saturation with Black Plane Compensation

Please make sure that you have assigned a printer profile to the printer queue according to the instructions given in Default Printer Profile above. This ensures that the values you specify in the “ICC Intents” section are used for printing.


Please keep the intent setting Automatic, unless you have a special reason to change it. Your profiling software will explain the intents meanings.

4.5 Using the HELIOS Admin printer log file to check OPI activities

You may use the HELIOS Admin program for both setting up OPI (before printing) and proofing OPI (after printing). In fact, the printer log files contain comprehensive information about how OPI has handled the images included in a given print job.


Select Printer Log Files from the Lists menu. Then click on the print job on which you wish to obtain OPI-related information.

Another possibility is to make a double-click on the print job in the “Hold queue” (Fig. 4.8).

Contents of a printer log file

Fig. 4.8: Contents of a printer log file

The log file will contain various messages that describe the respective print job. Some of the messages are OPI-specific. The OPI-related messages in this file inform you about:

For further information about HELIOS log files, please refer to the HELIOS Base manual.

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HELIOS Manuals October 14, 2021