Bug 141058 - PPTX to PDF: Images from deeper layers (covered by other objects) aren't omitted, and their decorative flag is ignored.
Summary: PPTX to PDF: Images from deeper layers (covered by other objects) aren't omit...
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Printing and PDF export (show other bugs)
(earliest affected)
Hardware: All All
: medium minor
Assignee: Not Assigned
Keywords: accessibility, filter:pptx
Depends on:
Blocks: PDF-Accessibility PPTX-Images
  Show dependency treegraph
Reported: 2021-03-16 09:59 UTC by Miroslav Michalek
Modified: 2022-11-29 09:24 UTC (History)
2 users (show)

See Also:
Crash report or crash signature:

Original ppt (979.59 KB, application/vnd.openxmlformats-officedocument.presentationml.presentation)
2021-03-16 10:01 UTC, Miroslav Michalek

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Description Miroslav Michalek 2021-03-16 09:59:05 UTC
When exporting 5 layer PPT. Images on layer 4 and 5 with the decorative flag aren't omitted or converted to artifact. They are then reported in an accessibility check.

Actual Results:
Images with decorative flags from background layers. They aren't omitted. They are converted into figure tags with an empty alt text.

Expected Results:
It should be omitted at all. Or do not convert to figure with empty alt text.

Reproducible: Always

User Profile Reset: No

Additional Info:
Version: / LibreOffice Community
Build ID: f6099ecf3d29644b5008cc8f48f42f4a40986e4c
CPU threads: 12; OS: Mac OS X 10.16; UI render: default; VCL: osx
Locale: ar-SA (en_CZ.UTF-8); UI: en-US
Calc: threaded
Comment 1 Miroslav Michalek 2021-03-16 10:01:15 UTC
Created attachment 170504 [details]
Original ppt
Comment 2 Buovjaga 2022-03-17 14:46:08 UTC
From the Navigator I can see what you mean, stuff like Picture 6. Please explain what is a decorative flag and how I can see it in the picture in the document.

Impress does not have layers as such. You are referring to the stacking order. So you are requesting that data loss would happen for elements that are underneath other elements.
Comment 3 QA Administrators 2022-09-14 03:38:48 UTC Comment hidden (obsolete)
Comment 4 QA Administrators 2022-10-15 03:40:32 UTC Comment hidden (obsolete)
Comment 5 Buovjaga 2022-10-18 08:42:22 UTC
I looked at this again, I unzipped the .pptx file and found these tags in the file ppt/slides/slide1.xml:

<adec:decorative xmlns:adec="http://schemas.microsoft.com/office/drawing/2017/decorative" val="1"/>

Bubli mentioned in the dev chat:
an image labelled that way should be exported as PDF /Artifact s.a. https://www.w3.org/WAI/WCAG20/Techniques/pdf/PDF4

Let's put this to NEW.