PDFs are not comparable with Acrobat Pro (tag problem?)

[Anonymous1]

Hello,

since switching to Oxygen, we cannot compare PDFs anymore using Acrobat Pro.

We want to provide our translators with compare PDFs, to allow them to proofread their translations while seeing which text is old and which text is new. This worked pretty well with our old PDFs (created with FrameMaker 11), but does not work with our PDFs created with Oxygen 17.1 using the build in FOP. An error message in Acrobat Pro says, that not the PDFs cannot be compared.

I have looked at the properties of our old FM and our new Oxygen PDFs. There are some differences:

FrameMaker PDF
- Created with Acrobat Distiller 10.1.15
- PDF Version 1.7 (Acrobat 8.x)
- PDF with tags: yes

Oxygen PDF
- Created with Apache FOP Version 1.1
- PDF Version 1.4 (Acrobat 5.x)
- PDF with tags: no


Maybe it is because of the missing tags? Normally it shouldn't be a problem that the PDF Version is older, because I could compare PDFs that had an even older PDF version.

Best regards,

Benjamin

[Radu]

Hi Ben,

I'm not sure how to help as there does not seem to be a document somewhere stating how the PDFs should be formatted internally in order for the comparison to work. Maybe you could write to Adobe and try to get some guidelines from them.
The Apache FOP PDF processor has a configuration file:

OXYGEN_INSTALL_DIR/frameworks/dita/DITA-OT2.x/plugins/org.dita.pdf2.fop/fop/conf/fop.xconf

which potentially could be modified in order to change some aspects of the PDF formatting:

https://xmlgraphics.apache.org/fop/2.1/ ... ation.html

Also you could try to install and publish with a commercial FO processor like XEP or Antenna House, maybe they work out of the box.

Regards,
Radu

[Anonymous1]

Thanks Radu.

The Apache FOP Accessibility settings do not work on my system.

Code: Select all

<fop version="1.0">

  <accessibility>true</accessibility>

  ...

</fop>

This leads to an error message when trying to render the PDF. I'll have a look at the documents you provided.

If nothing works, I'll have a look at commercial FO processors. But that would be a rather big step, considering besides this issue we are happy with Apache FOP. And contacting Adobe is also a good idea. But I don't expect such a great support as I get in this forum.

[Radu]

Hi,

Oxygen 18.0 comes with the latest Apache FOP 2.1. So if you are using an older version of Oxygen, you should try to see if the latest Apache FOP bundled with 18.0 can handle the accessibility tag. If not... probably a bug in Apache FOP, possibly something which is related to your actual content. If you can prepare a sample DITA project on which you can reproduce the error we could open an issue on the Apache FOP bug list.

Regards,
Radu

[Anonymous1]

Sorry for the delayed answer.

We will switch to Oxygen 18 in a few weeks. Then I will check out the Apacho FOP 2.1 and will get back at you with sample content if the problem still remains.

[Anonymous1]

I've checked this again with Oxygen 18 and the activated accessibility setting (userAgent.setAccessibility(true);).

The PDF properties are:

Created with: Apache FOP 2.1
PDF-Version: 1.5 (Acrobat 6.x)
PDF with tags: Yes

Now the PDF is accessible (checked with the Accessibility Check feature of Acrobat Pro), but still cannot be compared in Acrobat Pro.

What am I missing? Is anybody able to compare PDFs that have been produced with Apache FOP?

[Radu]

Hi Ben,

I would suggest that you register and ask around on the Yahoo Groups DITA Users List. Maybe there are users there who had tried this before.
The Oxygen forum is a more static place, most users are not registered to receive notifications for each post on any discussion thread.

Regards,
Radu

[Anonymous1]

If anybody else experiences this issue. The latest version of Acrobat Pro, called Acrobat Pro DC, fixed this issue for us.

Comparing works fine again with Acrobat Pro DC.