HELIOS Tech Info #103
Tue, 28 Nov 2006
PDF-native OPI workflow
HELIOS PDF HandShake UB features a new workflow option called PDF-native OPI. This option is available for customers who have ImageServer UB and PDF HandShake UB installed. PDF-native OPI supports transparency features in an OPI workflow, e.g. via the PDF export feature in Adobe InDesign CS2. It only works for raster-based (“bitmap”) images but not for vector-based EPS (object EPS).
Many customers wish to combine vector EPS images (e.g. from Adobe Illustrator) and raster-based images in Adobe InDesign for use with PDF-native OPI. This was already possible by avoiding to place layouts of high-resolution vector EPS images, and placing high-resolution vector EPS images directly instead.
This Tech Info describes the workflow and new options which are implemented via the updates described below.
Update u0572/u0573 (pdfresolve)
This update introduces a new option, “CheckRaster”, to enable the usage of layouts of vector EPS images in InDesign. Users can always use layouts and need not handle file formats differently during image placement, i.e. there is no need to distinguish between EPS and TIFF images.
If an EPS layout image of a vector EPS is placed in InDesign and if the document is exported as PDF, the PDF document contains an OPI reference which refers to the high-resolution vector EPS.
With “CheckRaster” set to TRUE (default) the image replacement is aborted with an error message because object-based images are not supported in PDF-native OPI. This error is desired if high-resolution object-based images are used by accident.
With “CheckRaster” set to FALSE, these specific unnecessary OPI image replacements are simply skipped, no error is generated and the image replacement resumes.
Update u0584/u0585 (opisrv and layout)
This update introduces a new “PDFNativeWorkflow” preference (type boolean, default FALSE). This preference enforces the generation of PDF-native workflow compatible layout images from vector-based EPS images, even if TIFF layout images are supposed to be generated, e.g. via a “%t” folder syntax. The advantage is that any layout image can be used in the PDF-native OPI workflow (see Note 1 below). The disadvantage is that these layout images may become larger since they always contain the high-resolution vector data. Of course, these layouts are still compatible with the usual PostScript based OPI workflow.
To enable this preference use the command:
prefvalue -k Global/Opi/PDFNativeWorkflow -t bool TRUE
To disable this preference use the command:
prefvalue -k Global/Opi/PDFNativeWorkflow -d
After changing this preference, “opisrv” needs to be restarted, e.g. via
srvutil stop -f opisrv
srvutil start opisrv
Now it is possible to place e.g. a TIFF layout of a raster-based image, and an EPS layout of a vector-based EPS in InDesign. Then the PDF must be exported using the “Omit Bitmap images” option in the InDesign “Advanced” export settings. EPS and PDF must not be omitted so that the resulting PDF document contains all the vector-based data which is included by InDesign. The omitted raster-based images will be replaced with high-resolution images via “pdfresolve”.
Placing a layout image from a high-resolution PDF in a PDF-native workflow is currently not supported. The high-resolution PDF must be placed in InDesign.
There is no need to change the “pdfresolve.pl” script. Since update u0558 there is a “RESOLVEOPTION” environment variable available which can be assigned in HELIOS Admin, to add “pdfresolve” command line options. It supports several options using a SPACE delimiter, e.g.
RESOLVEOPTION=-v -oIgnoreUntagged=TRUE -oCheckRaster=FALSE