Bug 139172 - Transparent objects placed on bitmaps appear solid when exported as PNG using "Selection" option
Summary: Transparent objects placed on bitmaps appear solid when exported as PNG using...
Status: RESOLVED WORKSFORME
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Draw (show other bugs)
Version:
(earliest affected)
7.2.0.0.alpha0+
Hardware: x86-64 (AMD64) Windows (All)
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2020-12-22 21:32 UTC by xordevoreaux
Modified: 2021-09-20 09:04 UTC (History)
2 users (show)

See Also:
Crash report or crash signature:


Attachments
full page PNG Export. (769.91 KB, image/png)
2020-12-22 21:33 UTC, xordevoreaux
Details
Selected objects only exported (709.27 KB, image/png)
2020-12-22 21:34 UTC, xordevoreaux
Details

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Description xordevoreaux 2020-12-22 21:32:23 UTC
Description:
Microsoft Windows -- most transparencies export fine for PNG if the entire page is exported, but treatment of transparencies when exported objects only produces solid color where transparency is expected.

Steps to Reproduce:
1. Launch Microsoft Windows LO Draw
2. Create a new draw document
3. Import a bitmap picture image
4. Place a square or other object with a color fill on top of the image
5. Set the object's transparency to something other than 0.
6. Export as PNG using the "Selection" option.

Actual Results:
Any portion of a transparent object overlapping a bitmap appears solid.

Expected Results:
How the page appears in LibreOffice is how it should appear when exported.
Again, this problem does not occur when the entire page is exported.


Reproducible: Always


User Profile Reset: No



Additional Info:
Version: 7.2.0.0.alpha0+ (x64)
Build ID: 4041c68ea59181f1c4774c356809066d2051db41
CPU threads: 8; OS: Windows 10.0 Build 21277; UI render: Skia/Vulkan; VCL: win
Locale: en-US (en_US); UI: en-US
Calc: CL
Comment 1 xordevoreaux 2020-12-22 21:33:32 UTC
Created attachment 168437 [details]
full page PNG Export.

The output here is very close (acceptably close) to the way the document appears in LO.
Comment 2 xordevoreaux 2020-12-22 21:34:27 UTC
Created attachment 168438 [details]
Selected objects only exported

The portion of the transparent square overlapping the bitmap appears solid. The area of the transparent square outside the bitmap is fine.
Comment 3 xordevoreaux 2020-12-22 21:39:00 UTC
Also note that an imported transparent object renders fine, as no work is done on it upon export. It's only objects in LO Draw with a transparency property set other than the default (no transparency) encountering an issue.
Comment 4 xordevoreaux 2021-01-28 15:15:34 UTC
Works for me now in

Version: 7.2.0.0.alpha0+ (x64) / LibreOffice Community
Build ID: 7eb289c49cc7245ef3001a39be0c15d06bbe875b
CPU threads: 8; OS: Windows 10.0 Build 21296; UI render: Skia/Raster; VCL: win
Locale: en-US (en_US); UI: en-US
Calc: CL