Bug 135258 - Cannot export slides to PNG when Master contains a transparent object
Summary: Cannot export slides to PNG when Master contains a transparent object
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Impress (show other bugs)
(earliest affected)
6.2 all versions
Hardware: x86-64 (AMD64) All
: medium minor
Assignee: Not Assigned
Keywords: bibisected, bisected, regression
Depends on:
Blocks: Graphics-Export
  Show dependency treegraph
Reported: 2020-07-29 08:29 UTC by Florian
Modified: 2021-02-23 04:27 UTC (History)
5 users (show)

See Also:
Crash report or crash signature:
Regression By:

Example file (14.16 KB, application/vnd.oasis.opendocument.presentation)
2021-02-22 16:59 UTC, Buovjaga

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Description Florian 2020-07-29 08:29:59 UTC
I created a master slide which has a symbol shape (puzzle) with 80% transparency in the background. When I export the presentation to PNG files, the transparent object is not visible in the PNG file.

Steps to Reproduce:
1. Create new presentation
2. Open Master view
3. Add symbol shape (e. g. puzzle)
4. Set the area transparency to 50%
5. Close Master view
6. Select File → "Export…"
7. Set export format to "PNG"
8. In PNG options, make sure "Save transparency" is checked
9. Click "OK"

Actual Results:
Error messages:

- Image filter not found
- General input/output error

Expected Results:
Slides are exported to PNG, no error message

Reproducible: Always

User Profile Reset: No

OpenGL enabled: Yes

Additional Info:
Build ID:
CPU threads: 4; OS: Linux 5.7; UI render: default; VCL: gtk3; 
Locale: de-DE (de_DE.UTF-8); UI-Language: en-US
Calc: threaded
Comment 1 Buovjaga 2021-02-22 16:59:13 UTC
Created attachment 169970 [details]
Example file


Arch Linux 64-bit
Version: / LibreOffice Community
Build ID: dec32864a61104001cb6ff63c218ea5fb2a7ab1e
CPU threads: 8; OS: Linux 5.10; UI render: default; VCL: kf5
Locale: fi-FI (fi_FI.UTF-8); UI: en-US
Calc: threaded
Built on 22 February 2021
Comment 2 Buovjaga 2021-02-22 17:01:01 UTC
Version: (x64) / LibreOffice Community
Build ID: 385808a2dff7300ec0120fdd5e8acfad8f86e50d
CPU threads: 2; OS: Windows 10.0 Build 19042; UI render: Skia/Raster; VCL: win
Locale: fi-FI (fi_FI); UI: en-US
Calc: threaded
Comment 3 Buovjaga 2021-02-22 17:46:17 UTC
This is already in oldest of Linux 6.3 repo, but not yet in newest of 50max repo.
Comment 4 Roman Kuznetsov 2021-02-22 21:27:25 UTC
I bisected it with win32-6.2 bisect repo and got a follow sha:



Added CC: to Armin Le Grand
Comment 5 xordevoreaux 2021-02-23 04:27:35 UTC Comment hidden (off-topic)