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HELIOS ImageServer UB User manual |
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The following chapters only explain OPI related dialogs. For an overall description of the HELIOS Admin program, please refer to the 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 UNIX commands. For advice on how to handle these commands, please refer to the reference guide in this manual (see 6 "ImageServer utility programs").
Important: 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.
Note: The following chapters describe the effects single settings will have. In A 1 "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.
The ImageServer Settings dialog contains three tabs in which you can define general OPI settings. These settings are valid for all layout images that are generated by ImageServer.
Select Settings > ImageServer Settings from the HELIOS Admin menu to open the OPI Color tab (Fig. 4).
Note: The Revert and Apply buttons remain disabled until you apply changes in the dialog.
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).
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.
- CMYK Euro 2.6 UCR-370
is the default setting and is best-suited if you want to separate your images according to the Euro standard.- CMYK SWOP 2.6 UCR-370
may be selected if you are working with the SWOP standard.- EBU RGB
may only be selected if your layout application is able to print composite and separations using TIFF-RGB images.- Lab D65
may only be selected if your layout application is able to import Lab layout images.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 EBU RGB 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 Euro or SWOP.
- Excellent
Layout images are color matched automatically and are subjected to a high-quality downsampling method. Excellent is the default setting.- Standard
Layout images are generated very fast but they are not as excellent in quality, and are not color matched.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:
- TIFF Gray and Bilevel Compress (only for Grayscale and Bilevel images)
- EPSF 8-bit Screen Preview (EPSF screen preview containing indexed colors = max. 256 colors)
- EPSF JPEG Printable Preview (JPEG compressed EPSF printable preview)
- Ignore mask for bitmap images during output causes an existing clipping path to be ignored when printing images, and therefore during final high-resolution output (see also 3.3.4 "Application clipping paths").
- Ignore Additional Channels for Bitmap Images causes additional channels (e.g. spot colors) to be omitted when creating a layout image, and therefore during final high-resolution output (see also 3.3.5 "Additional channels in bitmap images").
This item serves to define the default monitor resolution for your layout files. Monitor resolutions usually have a range between 72 and 100 dpi.
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.
Note: 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.
- .lay
If you activate this option, the ".lay" extension will be added to all your layout files. We do not recommend using this option because some applications (under Windows) will not accept file names using this extension.- 'layouts' Folder
Is the default setting and will induce OPI to create a subfolder named "layouts" (within the folder that contains the high-resolution images), and collect all layouts in this subfolder. The layout files will not have the specific ".lay" extension.Note: Folders may be configured separately, i.e. you can define for all layout images in a specific folder several parameters (e.g. resolution or color space) that differ from the default settings on your server (see 5.3 "Defining folder specific OPI settings" for details).
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 files being generated from temporary files.
Important: 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 5.6 "Refreshing layouts using the "touch" program"), or use the "opitouch" program (see 6.3 "opitouch").
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.
The Image Search Paths window shows the 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. 7).
Note: Detailed explanations on how ImageServer deals with image search paths are given in 3.7 "How ImageServer finds and replaces image files".
Some OPI settings are volume-dependent. To edit the settings for a specific volume do the following:
The dialog shown in Fig. 8 will display all specific settings you have entered when defining the volume (for advice on how to define a new volume, please refer to the Base manual). There are only two items in the dialog that are important for the configuration of OPI, namely the checkboxes Create Layouts and PC Layouts.
This option serves to activate automatic generation of layout files. As soon as you switch on Create Layouts, the OPI server will generate a low-resolution layout file of every high-resolution image file you subsequently save on 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).
File characteristics are slightly different on Macintosh 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 Macintosh computer; OPI generates layout files always according to the PC Layouts checkbox in the HELIOS Admin volume settings (Fig. 8).
Note: Since the Macintosh 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 A 4 "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). This may be disadvantageous if you are working with clipping paths (compare 3.3.3 "Image paths and clipping paths").
Some OPI settings are only meant for printing, and have to be set up for every single printer queue.
Note: 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 Base manual.
Highlight a printer from the Printers list and then select Printer > Settings from the HELIOS Admin menu and go to the OPI Setup tab to open the dialog shown in Fig. 9.
The OPI Active option enables OPI for this specific printer queue, and at the same time activates the "OPI Printer Setup" section.
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 = 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 5.7 "OPI print options - include or omit images").
If you activate Check Images, the OPI server will try to find all images that are included in a print job. If any images are missing, the job will be stopped, and an error message is issued for every missing file. 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.
The Check Fonts command 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 (e.g. 300 dpi) is higher than the value in this dialog (e.g. 144 dpi in Fig. 9), 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 (running from 18 to 360 dpi) and the PPD Default option. If you select PPD Default the OPI server will use the dpi value that is stated in the PPD file. You may also specify a custom value for downsampling. Selecting None from the list will switch downsampling off. Every image will then be printed according to its particular resolution.
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:
The CCITT Group 4 compression is a very good lossless linework compression available, which 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.
Highlight a printer from the Printers list and then select Printer > Settings from the HELIOS Admin menu and go to the OPI/ICC tab to open the dialog shown in Fig. 10.
Activating Check ICC Profiles for Pictures will induce 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.
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.
- None
Switches color matching off.- Browse-
Opens a dialog that lets you select a specific profile.- EBU RGB
May be selected if you want to "print" to a slide-recorder or if you use the "Print To Disk" option or PDF HandShake to convert your documents into PDF.- Lab D65
Best-suited if you want to select a device independent output color space, e.g. if you send your documents to different production sites (see also 3.4 "About output devices").This item becomes only available if you have selected a default printer profile. Here, you can select the correct profile for your proof printer.
Note: It does not make any sense to select a proof profile if you have chosen Lab D65 from the Default Printer Profile pull-down menu. In that case, you have not yet specified your output device and thus cannot simulate it with a proof printer.
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, 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.
This feature offers different "strategies" for rendering an image file from one color space to another. There are 5 settings (Automatic, Perceptual, Relative Colorimetric, Saturation, Absolute Colorimetric).
Please make sure that you have mounted the "ICC-Profiles" volume and assigned a printer profile to the printer queue according to the instructions given in Default Printer Profile above. This ensures that the values you may specify in the "ICC Intents" section are recognized by the OPI server. If no "ICC-Profiles" volume is mounted, ImageServer will produce an error message.
Note: Please keep the intent setting Automatic, unless you have a special reason to change it. Your profiling software will explain the intents meanings.
You may use the HELIOS Admin program for both setting up OPI (before printing) and watching 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 and specify the required day. Then click on the print job on which you wish to obtain OPI-related information.
| © 2005 HELIOS Software GmbH |
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