Using PDF Image Replacement

This section describes scenarios for integrating PDF Image Replacement into production. The Xinet Client Guide presents similar information that is intended to help both local and remote users work more efficiently with PDF Image Replacement.

In addition, Xinet TechNote 315 discusses the use of FPOs versus high-resolution images in PDF Image Replacement workflows.

General notes about using Adobe InDesign in a PDF Image Replacement workflow

Xinet engineers have developed InDesign plug-ins that install Export Adobe PDF presets for InDesign (called Xinet PDF/IR Local Workflow and Xinet PDF/IR Remote Workflow) and a Xinet PDF Upload option to help ensure that InDesign PDF-IR workflows remain error-free. The following is an example of Xinet PDF Image Replacement suggested settings for local (volume mounted) workflows..

So, for the most part, layout staff can incorporate images in layout files in the way that is most convenient, and then, during the Export process, the Xinet InDesign plug-ins will check image links and issue a series of prompts should anything need adjustment.The PDF Image Replacement Export prompts will guide operators through the InDesign PDF Export process..

 

Local workflow with InDesign

If a member of a production staff is working on the same network as the Xinet server, for example., he or she can mount Xinet Volumes locally on the desktop, he or she is using a local workflow.

Note that the Image Replacement options described below are drawn from InDesign Creative Suite usage. In order to run a PDF successfully through a PDF Image Replacement queue, Macintosh and Windows clients with local access to a Xinet AppleShare or SMB Volume need to make sure the following two conditions are met:

1.	Place images from a mounted Xinet Volume. It doesn't matter if they place FPOs from an FPO Volume or high-resolution images from a High Resolution Volume.

2.	At the time they export PDFs from InDesign, make sure they use the export setting called Xinet PDF IR local workflows.

The Thin PDF can be dropped in a published Hot Folder that will then send the file on for successful PDF Image Replacement.

Since there are no FPO Volumes on PCs, Xinet Volumes need to be shared using the Xinet PC Connectivity software. If this requirement has been met, TIFFs, EPSs, or PDFs can be placed in an InDesign document on a PC and exported using Omit EPS, PDF and Bitmap Images. Note that OPI export settings need to be set manually since there is no Xinet PDF IR local workflows under Adobe PDF Presets.

Some background information for local workflows

If thinking about changing the Xinet-recommended Export settings, operators should note that PDF Image Replacement will not work with PDF/X. PDF/X certification must be turned off in layout programs’ Export dialogs because PDF/X specifications disallow Image Replacement tags or transparent elements to be included in the document. Also, exporting to a PDF version lower than PDF 1.4, or any form of PDF/X certification, will force transparency flattening. The flattening process may break images up into many “slices” and then alter the pixel values of some of these slices, making Image Replacement impossible.

Since the Xinet PDF Export settings for local workflows are set to OMIT Bitmaps, PDFs, and EPS in the Export Dialog Advanced tab, it might be important to understand the following consequences:

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A Thin PDF with placed high-resolution images that is exported with the Xinet PDF Export settings for local workflows might take longer to render and will be larger in size. This is because high-resolution images need to be embedded in the exported PDF. Placing high-resolution images provides all the benefits of InDesign’s import options (such as placing only certain layers of PSD files etc.).

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Since EPS FPOs are unable to contain transparency information, InDesign will always omit EPS FPOs if configured to do so. The preview of an EPS FPO can contain transparency, but InDesign only uses the preview for viewing at low-resolution on the screen. High Quality Display mode and the exported Thin PDF will ignore the preview, and the transparency will be lost until the image is uploaded and PDF Image-Replacement replaces it. This means the Thin PDF will be smaller, and it will export and upload faster. However, effects that rely on the transparent outline of the image (such as drop shadows) will not be as accurate.

Remote workflow with InDesign

When planning to do page layout in a local environment and then upload PDFs to a Xinet server, operators are using a remote workflow. The only access to Xinet volumes will be via a browser pointed at a Xinet server, where FPOs or high-resolution images will be procured and then placed in layout applications. Operators may also incorporate high-resolution images, either from the server or their local environments.

In short, in order to successfully deliver Thin PDFs exported from InDesign on a remote site, operators should be aware that:

1.	Downloaded FPOs, downloaded high-resolution or local high-resolution images can be placed. The FPOs must be EPS type FPOs. See Fine tuning preview generation for details about this.

2.	At the time the PDF is exported from InDesign, operators should make sure to use the Adobe PDF Presets Export setting called Xinet PDF IR remote workflows or use the Xinet PDF Upload function under the File menu in InDesign.

At this point, remote Macintosh clients are ready to use Xinet Uploader to upload Thin PDFs to the Xinet volume, which will contain a Hot Folder that will produce Fat PDFs as output. InDesign CS 3–CS 5 users can use the Xinet PDF Upload option (found in the InDesign File pull-down menu) to export PDFs from InDesign that go directly to the Xinet server via a Xinet Uploader. Windows users in remote workflows must use EPS FPOs or optional local high-resolution images and export PDFs using the Include option.

There are a number of ways to obtain Xinet FPOs, such as using the built-in Xinet Download functionality, downloading groups of images through Collections, dragging and dropping from Pilot windows directly into layout applications, or, for InDesign users with Xinet Portal access, acquiring FPOs through the Add to Collection functionality.

Once layout is complete, Xinet recommends that operators use either the Xinet PDF IR remote workflows export option from within InDesign or the Xinet PDF Upload option in order to transfer the exported PDF to the PDF Image Replacement queue on the Xinet Server.

Both options are made possible through Xinet plug-ins. (Once again, About Xinet Client Extensions and Plug-ins provides details about them.)

Some background information about remote workflows

A Thin PDF with placed high-resolution images that has been exported using the Xinet PDF IR remote workflows setting might take longer to render and be larger in size, since it would contain all high-resolution images. The Xinet Image Replacement engine will find those images and convert them, according to the settings specified in the PDF Image Replacement queue.

A Thin PDF, made by exporting a PDF with placed FPO images, may encounter problems with the representation of transparencies when viewed in a PDF reader, such as Adobe Acrobat. This is due, once again, to the lack of transparency support in PostScript: the EPS format cannot convey transparency information. Because of this, EPS FPOs do not contain transparency information in the image data. (There is transparency information within the TIFF preview that’s inside the EPS FPO, but that’s only used for screen viewing in the layout application and not used in the Thin PDF.) Because EPS files cannot contain transparency, the transparency is lost in the Thin PDF and the images show with a rectangular background, making the Thin PDF unreliable as a preview of any final results.

In a remote workflow, Xinet recommends placing EPS FPOs, or a combination of FPOs and high-resolution images, and then exporting using the Xinet PDF IR remote workflows setting.

General notes about using Adobe Illustrator in a PDF Image Replacement workflow

In order to create PDFs from Illustrator that work in PDF Image Replacement workflows, operators should place either EPS FPOs or high-resolution images. (See Make EPS FPOs from all image formats for details about forcing the server to generate only EPS FPOs). Please note that FPOs only work when linked, not embedded. Also, operators should be sure, when working with FPOs, that they enable the File Handling & Clipboard Preference, Use Low Resolution Proxy for Linked EPS option. It will provide better-looking screen previews when linked images incorporate effects such as soft-edged masks, although the soft-edge masks will still look “hardened.”

Operators may use the Save As dialog to direct a PDF file generated from Illustrator to a PDF Image-Replacement-enabled Hot Folder.

In addition, in versions of Adobe Illustrator that support it, documents saved in the native Illustrator format with Create PDF Compatible File turned on will be acceptable as a Thin PDF, and the PDF Image Replacement process will make a valid Fat PDF. However, the ability to further edit the PDF in Illustrator after the PDF Image Replacement process is not guaranteed. (Operators may want to make a copy of the file first, as normally, Hot Folders delete files after successfully processing them.)