Bug 161620 - In Draw: Background transparency setting don't follow exporting to PNG.
Summary: In Draw: Background transparency setting don't follow exporting to PNG.
Status: RESOLVED NOTABUG
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Draw (show other bugs)
Version:
(earliest affected)
24.2.1.2 release
Hardware: x86-64 (AMD64) Windows (All)
: medium minor
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-06-17 15:28 UTC by Rene Hache
Modified: 2024-06-22 04:25 UTC (History)
2 users (show)

See Also:
Crash report or crash signature:


Attachments
Screenshot montage of an example. (573.99 KB, image/png)
2024-06-17 15:57 UTC, Rene Hache
Details
sample ODG (107.25 KB, application/vnd.oasis.opendocument.graphics)
2024-06-18 04:25 UTC, Stéphane Guillou (stragu)
Details
Draw background Test for compare (716.68 KB, image/png)
2024-06-21 19:42 UTC, Rene Hache
Details
Stéphane's example on my laptop (1.02 MB, image/png)
2024-06-21 19:57 UTC, Rene Hache
Details

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Description Rene Hache 2024-06-17 15:28:04 UTC
Description:
When exporting a page from a Draw document to PNG, the transparency setting don't apply to the exported PNG image, even if the "Save Transparency" setting is on.

Steps to Reproduce:
1. Have a document with a background photo that have a transparency set (mine was at 40%)
2. Export the page to PNG (didn't test other format) (File > Export... > format: PNG)
3. View exported image in your assigned photo/image viewer (mine is IrFanView)

Actual Results:
Background transparency didn't apply, show background has no transparency.

Expected Results:
Software should apply transparency to the background picture/image when exported to a photo/image file format.


Reproducible: Always


User Profile Reset: No

Additional Info:
Easy workaround if you know photo editing.

---
Version: 24.2.1.2 (X86_64) / LibreOffice Community
Build ID: db4def46b0453cc22e2d0305797cf981b68ef5ac
CPU threads: 8; OS: Windows 10.0 Build 22631; UI render: Skia/Raster; VCL: win
Locale: en-CA (en_CA); UI: en-GB
Calc: threaded
---

The About box say Windows 10.0, but it's suppose to be Windows 11 Home that I'm using. Also this is a new laptop that I purchase in March 2024.
Comment 1 Rene Hache 2024-06-17 15:57:58 UTC
Created attachment 194783 [details]
Screenshot montage of an example.

Screenshot montage of an example.
Comment 2 m_a_riosv 2024-06-18 00:52:24 UTC

*** This bug has been marked as a duplicate of bug 98954 ***
Comment 3 Stéphane Guillou (stragu) 2024-06-18 02:17:25 UTC
Bug 98954 is specific to Writer, let's keep it separate.
Trying to reproduce now.
Comment 4 Stéphane Guillou (stragu) 2024-06-18 04:25:18 UTC
Created attachment 194789 [details]
sample ODG

I could not reproduce with the attached sample ODG and:

Version: 25.2.0.0.alpha0+ (X86_64) / LibreOffice Community
Build ID: 6f4adc1274cfac30b9097411bb193bd4386969f0
CPU threads: 8; OS: Linux 6.5; UI render: default; VCL: gtk3

Nor in:

Version: 24.2.4.2 (X86_64) / LibreOffice Community
Build ID: 51a6219feb6075d9a4c46691dcfe0cd9c4fff3c2
CPU threads: 8; OS: Linux 6.5; UI render: default; VCL: gtk3

Can you please update to the latest 24.2 release, and provide an example document if you can still reproduce?
Thank you.
Comment 5 Rene Hache 2024-06-21 19:41:02 UTC
I updated to the latest version 24.2.4.2 (Hate updating, it reset my LibreOffice docuemnts pins on the taskbar icon, but that's a Windows issue, not LibreOffice)

Still do the same thing, but with more research, recreating from a new test file, and a detail I forgot to check last time, I notice that exported PNG is indeed more transparent than the original JPG of the background, but still not as quite transparent as the ODG when I have it open on my screen. If I compare all 3 version of the background (original, PNG export and in Draw) I have 3 different transparency. It could be my screen and not LibreOffice.

I will add "Draw BG Test Compare" as an example. It's not a huge deal, I could just increase the transparency a little more before exporting.
Comment 6 Rene Hache 2024-06-21 19:42:02 UTC
Created attachment 194901 [details]
Draw background Test for compare
Comment 7 Rene Hache 2024-06-21 19:57:08 UTC
Created attachment 194902 [details]
Stéphane's example on my laptop

Stéphane's example on my laptop, A little difference between the 2 version. Like I said, it could be my screen, I even test different screen brightness settings, still always a litte different. I wonder if it's something else on my laptop that could cause this.
Comment 8 Stéphane Guillou (stragu) 2024-06-21 23:14:58 UTC
The issue is that the app you use for looking at the image uses a different background that blend with your transparent image. If you want to compare apples to apples, please open the image in an application that uses a white background behind images. For example, Firefox does that, in my tests. Or change Irfan's background colour: https://irfanview-forum.de/forum/program/support/1264-
Comment 9 Rene Hache 2024-06-22 02:36:20 UTC
Ok, Thank You. So sorry for all the trouble and for taking your precious time.
Comment 10 Stéphane Guillou (stragu) 2024-06-22 04:25:18 UTC
No problem at all Rene, thank you for reporting issues you run into!