Bug 166338 - LO Impress: pixelated view when hitting F5
Summary: LO Impress: pixelated view when hitting F5
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Impress (show other bugs)
Version:
(earliest affected)
7.5.0.3 release
Hardware: All All
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords: bibisected, bisected, regression
Depends on:
Blocks:
 
Reported: 2025-04-25 15:01 UTC by Joachim Otahal
Modified: 2025-04-28 11:57 UTC (History)
3 users (show)

See Also:
Crash report or crash signature:


Attachments
Document to test, pixelated when F5. (2.00 MB, application/vnd.openxmlformats-officedocument.presentationml.presentation)
2025-04-25 15:02 UTC, Joachim Otahal
Details
What it looks likie with F5 (669.15 KB, image/jpeg)
2025-04-25 16:21 UTC, Joachim Otahal
Details
Edit mode is fine (574.05 KB, image/jpeg)
2025-04-25 16:22 UTC, Joachim Otahal
Details
F5 view, but with remarks (316.99 KB, image/jpeg)
2025-04-25 16:23 UTC, Joachim Otahal
Details
Libre Office Pixelated 04 tried origina-size result (m_a_riosv) (245.77 KB, image/jpeg)
2025-04-25 16:47 UTC, Joachim Otahal
Details

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Description Joachim Otahal 2025-04-25 15:01:26 UTC
Description:
When editing everything is fine. When hitting F5 several lines are not even drawn, bitmaps are pixelated, some off place.

Steps to Reproduce:
1. Get my Document: https://joumxyzptlk.de/tmp/libreoffice/libre-office-pixelated-when-hitting-f5.pptx
2. Have a screen at 4K, 'cause I only have 4K and it might be related to that.
3. Hit F5


Actual Results:
Pixelated view, even lines missing. Like it renders at 1024x768 instead of 4k (3840x2160).
(Asked at https://ask.libreoffice.org/t/impress-slideshow-pixelated-images-why/121244 )
Result: https://ask.libreoffice.org/uploads/asklibo/original/3X/e/d/ed8f0c13897c048346aa2a7278753f179691f1bf.jpeg
Annotated result: https://ask.libreoffice.org/uploads/asklibo/original/3X/3/a/3ab1e20161d5df0f54dd58ef048b858daab93d94.jpeg
When editing everything is fine. Including export as jpeg PDF etc.: https://ask.libreoffice.org/uploads/asklibo/original/3X/6/6/66a146e71921072d6fd7c315179f814f3bf68b91.jpeg


Expected Results:
Sharp view.


Reproducible: Always


User Profile Reset: Yes

Additional Info:
Reproduced on Server 2022 and Windows 11 24h2, with two different builds.

Version: 25.2.2.2 (X86_64) / LibreOffice Community
Build ID: 7370d4be9e3cf6031a51beef54ff3bda878e3fac
CPU threads: 4; OS: Windows 10 X86_64 (10.0 build 20348); UI render: Skia/Vulkan; VCL: win
Locale: de-DE (de_DE); UI: en-US
Calc: CL threaded
GPU: Titan RTX (the one from December 2018, Turing generation)
CPU: AMD Ryzen 5950x

Version: 24.8.6.1 (X86_64) / LibreOffice Community
Build ID: 051bf11303684a0a982c9966e8be766d0a9efbc7
CPU threads: 32; OS: Windows 11 X86_64 (10.0 build 26100); UI render: Skia/Vulkan; VCL: win
Locale: de-DE (de_DE); UI: en-US
Calc: CL threaded
GPU: Intel integrated
CPU: I5-6300U

Switching OpenCL off did not change anything.
Comment 1 Joachim Otahal 2025-04-25 15:02:53 UTC
Created attachment 200517 [details]
Document to test, pixelated when F5.

Document to test, pixelated when F5.
Comment 2 Joachim Otahal 2025-04-25 16:21:52 UTC
Created attachment 200522 [details]
What it looks likie with F5
Comment 3 Joachim Otahal 2025-04-25 16:22:32 UTC
Created attachment 200523 [details]
Edit mode is fine
Comment 4 Joachim Otahal 2025-04-25 16:23:02 UTC
Created attachment 200524 [details]
F5 view, but with remarks
Comment 5 m_a_riosv 2025-04-25 16:41:24 UTC
Maybe related to https://bugs.documentfoundation.org/show_bug.cgi?id=92375.

The line is a very reduced graphic. Select right-click original size.

In normal mode, when changing the scale, in some of them, it becomes invisible.
Comment 6 Joachim Otahal 2025-04-25 16:47:01 UTC
Created attachment 200529 [details]
Libre Office Pixelated 04 tried origina-size result (m_a_riosv)
Comment 7 Joachim Otahal 2025-04-25 16:56:52 UTC
(In reply to m_a_riosv from comment #5)
> Maybe related to https://bugs.documentfoundation.org/show_bug.cgi?id=92375.
> 
> The line is a very reduced graphic. Select right-click original size.
> 
> In normal mode, when changing the scale, in some of them, it becomes
> invisible.

Erm, no, Result "original size" is:
https://bug-attachments.documentfoundation.org/attachment.cgi?id=200529
but even when 1:1 would be used, i.e. as it is, the graphics would be too big. Lower resolution does not look good when printing.
I fon't think it is related to the bug you link, since the file is fine. it is <bold>ONLY the F5 "presentation" view fails</bold>, like it renders those pixel-graphics i use at 960x720 instead of 3840x2160, while the rest is rendered as expected.
The "960x720" is not just an accidental guess: When I do "Export as JPEG" it is the resolution offered. I enter 2160 as height (width is set to 2880 automatically), export it, and then it looks fine. The 960x720 jpeg version is low res, but at least all lines are drawn.
Comment 8 Telesto 2025-04-26 22:02:50 UTC
I judged the quality by the lines in the solar panels. Those are missing


Repro with
Version: 25.8.0.0.alpha0+ (X86_64) / LibreOffice Community
Build ID: 7fac8458e35620b9855cc6c68a9675159a849b65
CPU threads: 8; OS: macOS 14.7.4; UI render: Skia/Raster; VCL: osx
Locale: nl-NL (nl_NL.UTF-8); UI: en-US
Calc: threaded

also found in
Version: 7.5.0.3 (X86_64) / LibreOffice Community
Build ID: c21113d003cd3efa8c53188764377a8272d9d6de
CPU threads: 8; OS: Mac OS X 14.7.4; UI render: Skia/Metal; VCL: osx
Locale: nl-NL (nl_NL.UTF-8); UI: en-US
Calc: threaded

fine with
Version: 7.4.0.3 / LibreOffice Community
Build ID: f85e47c08ddd19c015c0114a68350214f7066f5a
CPU threads: 8; OS: Mac OS X 14.7.4; UI render: Skia/Metal; VCL: osx
Locale: nl-NL (nl_NL.UTF-8); UI: en-US
Calc: threaded
Comment 9 Saburo 2025-04-28 08:52:12 UTC
Bisect whether the presentation image is jagged

Version: 7.3.6.0.0+ (x64) / LibreOffice Community
Build ID: 8a3548eb859553a930a6120105cd30b3cc0ffeb3

author	Miklos Vajna <vmiklos@collabora.com>	2022-08-03
commit 8a3548eb859553a930a6120105cd30b3cc0ffeb3
tdf#149943 vcl: fix pixelated PDF export and print for a rotated image
The bugdoc has a barcode which looks good in Writer, but it's quite
blurry in the PDF export result.

This is a problem since commit dd4a67084853a030bf4b9f1f85d728620e0604a5
(vcl: avoid downscale && upscale in DrawTransformedBitmapEx(),
2019-10-08), where the motivation was to not downscale a bitmap in case
it has a larger amount of pixels but a smaller logic size. This went
wrong here and resulted in a blurry bitmap for a not so small image.

Fix the problem by mostly reverting the above commit, because it's no
longer necessary: 68549e00d5e23aa22bc974a8151d93cd948444b3 (vcl,
BitmapEx transformed draw: special-case simple rotations, 2019-10-10)
already made sure that the rotation case doesn't use scaling from the
transform.

testTdf128630 has been adapted to pass again (after manually verifying
that the bugdoc export result is still OK), now the bad case there
simply produces a smaller bitmap.

(cherry picked from commit 7c94d7267bc8b5f43185204ab4953c4b188214bf)

Change-Id: Ib28881c129a0cf037a96eecd065e5cadede97051
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/137743