Bug 142047 - Loss of image quality converting ODP to PPTX
Summary: Loss of image quality converting ODP to PPTX
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Impress (show other bugs)
Version:
(earliest affected)
7.1.2.2 release
Hardware: All Linux (All)
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks: PPTX-MasterSlide
  Show dependency treegraph
 
Reported: 2021-05-03 07:34 UTC by Tim Chambers
Modified: 2021-10-04 11:31 UTC (History)
2 users (show)

See Also:
Crash report or crash signature:


Attachments
Original OPD file with clear images (6.72 MB, application/vnd.oasis.opendocument.presentation)
2021-05-03 07:35 UTC, Tim Chambers
Details
PPTX file with poor quality images and no page numbers (6.45 MB, application/vnd.openxmlformats-officedocument.presentationml.presentation)
2021-05-03 07:36 UTC, Tim Chambers
Details
The larger background image in the ODP and PPTX version of the file (581.88 KB, image/png)
2021-05-03 14:42 UTC, NISZ LibreOffice Team
Details
The smaller background image in the ODP and PPTX version of the file (477.54 KB, image/png)
2021-05-03 14:51 UTC, NISZ LibreOffice Team
Details

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Description Tim Chambers 2021-05-03 07:34:36 UTC
Description:
Presentation created in Impress as an ODP file, then converted to PPTX using Save As.

Images used in slide headings were severely blurred when converted and no longer recognisable.

Also, the page numbers were no longer visible.

Steps to Reproduce:
1.Create presentation and include images in the title tpage as a background to the title
2.Save as ODP
3.Save as PPTX

Actual Results:
Images blurred.

Page numbers lost

Expected Results:
Visual equivalence between the ODP and PPTX versions


Reproducible: Didn't try


User Profile Reset: No



Additional Info:
Converting to PPTX is required to give the presentation at another organisation.
Comment 1 Tim Chambers 2021-05-03 07:35:53 UTC
Created attachment 171597 [details]
Original OPD file with clear images
Comment 2 Tim Chambers 2021-05-03 07:36:45 UTC
Created attachment 171598 [details]
PPTX file with poor quality images and no page numbers
Comment 3 Tim Chambers 2021-05-03 07:37:49 UTC
Images displayed as content were not affected, just the ones used as background in the title page and the slide headers
Comment 4 NISZ LibreOffice Team 2021-05-03 14:42:07 UTC
Created attachment 171612 [details]
The larger background image in the ODP and PPTX version of the file

Looks like some image settings are incorrectly exported to PPTX:
* The width and height of the image is doubled.
* The Position becomes Top Left instead of Top Center.
Comment 5 NISZ LibreOffice Team 2021-05-03 14:51:01 UTC
Created attachment 171613 [details]
The smaller background image in the ODP and PPTX version of the file

The smaller image also becomes larger, also its positioning changes from Bottom Right to Top Left.
Comment 6 NISZ LibreOffice Team 2021-05-03 14:53:00 UTC
Manually changing these values back to their original restores the look of the images in the PPTX version.

Version: 7.2.0.0.alpha0+ (x64) / LibreOffice Community
Build ID: 9c930c4f3109d123c0831d0fcecf9c8b32e5bbc7
CPU threads: 4; OS: Windows 10.0 Build 18363; UI render: Skia/Raster; VCL: win
Locale: hu-HU (hu_HU); UI: en-US
Calc: CL
Comment 7 Tim Chambers 2021-05-03 23:18:08 UTC
Thanks - the workaround is good to know