Bug 64664 - PDF: Rotated text corrupted when flattening transparent objects for PDF/A
Summary: PDF: Rotated text corrupted when flattening transparent objects for PDF/A
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Drawing (show other bugs)
Version: 4.0.3.3 release
Hardware: Other Linux (All)
: medium major
Assignee: Not Assigned
QA Contact:
URL:
Whiteboard: BSA
Keywords:
Depends on:
Blocks:
 
Reported: 2013-05-16 08:50 UTC by Jim Avera
Modified: 2013-07-05 18:09 UTC (History)
1 user (show)

See Also:
i915 platform:
i915 features:


Attachments
draw doc showing the bug (11.51 KB, application/vnd.oasis.opendocument.graphics)
2013-05-16 08:50 UTC, Jim Avera
Details
Screen-shot showing what the "bug.odg" looks like in LO (83.41 KB, image/png)
2013-05-16 08:52 UTC, Jim Avera
Details
PDF/A pdf showing corrupted (mostly missing) text (190.56 KB, application/pdf)
2013-05-16 08:53 UTC, Jim Avera
Details

Description Jim Avera 2013-05-16 08:50:52 UTC
Created attachment 79388 [details]
draw doc showing the bug

PDF/A does not allow transparency.  So when exporting to PDF with the PDF/A option selected, any transparent objects are converted to images (with a warning). 

However if there is rotated (e.g. vertical) text near by, the text gets corrupted in the resulting PDF -- most pixels are invisible.  Moving the text further away from the transparent objects makes the problem disappear, so I suspect there is a bug where the rotated bounding box is not used where it should be (or vice versa).  Or something like that.

STEPS TO REPRODUCE:
1. Load attached "bug.odt" drawing into LO
2. File->Export->PDF, select PDF/A option, and save.
3. View the resulting pdf with acroread -- the text is corrupted


Operating System: Ubuntu
Version: 4.0.3.3 release
Comment 1 Jim Avera 2013-05-16 08:52:30 UTC
Created attachment 79389 [details]
Screen-shot showing what the "bug.odg" looks like in LO
Comment 2 Jim Avera 2013-05-16 08:53:19 UTC
Created attachment 79390 [details]
PDF/A pdf showing corrupted (mostly missing) text
Comment 3 Joel Madero 2013-06-23 03:43:37 UTC
Thank you for reporting this issue! I have been able to confirm the issue on:
Version: 4.2.0.0.alpha0+Build ID: b0a1666f756aa5f5315366eca9d7d02ddd55d2b
Date:   Tue May 28 08:51:01 2013 +0300 
Platform: Bodhi Linux 2.2 x64

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As I've been able to confirm this problem I am marking as:

New (confirmed)
Minor - won't prevent high quality work but if a user ignores the warning about transparency and sticks with PDF/A despite having transparency, this bug may slow down their work as they'd have to re-export as regular PDF to get results they want. 
Low - seems like it really wouldn't impact many people - most people exporting pdf's are using regular pdf export not PDF/A - on top of this only affecting users using transparency and ignoring the warning about PDF/A and transparency not being friendly


Thanks for the report!

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Comment 4 Jim Avera 2013-07-01 23:27:22 UTC
PDF/A is a variant of PDF designed for long-term archiving.  Unlike regular PDFs, PDF/A does not depend on external data to be rendered.  For example, it does not depend on certain fonts being pre-installed in your rendering mechanism (printer or software print driver).  A key requirement for archival documents is that they can be rendered in the future without relying on specific printers or software companies continuing to exist.

So "re-export as regular PDF" is not a solution for people creating documents to be archived for a long time.

I think there is no valid work-around.  It's not a terrible limitation to not support PDF/A (when certain embedded images are present), but it is a non-minor bug IMO.

Best,
-Jim
Comment 5 Jim Avera 2013-07-01 23:31:27 UTC
Following up, it would be helpful if the bug could be *detected* and the user warned of possible corruption, even if the bug is too hard to fix right now.

Currently the "archival" PDF is silently corrupted.  Certain bits just disappear.
Comment 6 Joel Madero 2013-07-02 05:19:23 UTC
You've sold me on it being a bigger deal than I first thought. 

Upping it to normal - high due to the silent corruption

Major - Corrupts data

Medium - while I agree with your assessment I still think it's affecting a low number of users so bumped it down from default of high.

Do you happen to know if this problem exists on 3.6?
Comment 7 Joel Madero 2013-07-02 05:20:29 UTC
I meant Major - Medium - my bad :)
Comment 8 Jim Avera 2013-07-05 18:09:58 UTC
> Do you happen to know if this problem exists on 3.6?

The bug is present in 3.5.7.2 (I don't have 3.6 installed).


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