A recent, briefly-specified Office Drawing Extension (adding the svgBlip tag) allows SVG content to be embedded in OOXML WordprocessingML without loss of backward-readability. See:
LibreOffice does not appear to avail itself of this mechanism.
Without knowing the criteria for selecting OOXML extensions supported by LibreOffice: I'll just observe that SVG images are pretty widespread, and LibreOffice is even now able to read SVG "improperly" embedded in OOXML as if it was any other supported format.
This extension is briefly discussed in the context of the pandoc project here (including XML snippet):
May also be relevant to bug #121831.
Steps to Reproduce:
1. Embed SVG in OOXML WordprocessingML document using a recent (2016+?) version of Office Word
2. Open in LibreOffice.
SVG is suppressed, PNG fallback is used instead.
If the extension was supported, SVG would be displayed.
User Profile Reset: No
For what it's worth, manually replacing the PNG fallback image reference with a reference to the SVG image actually allows the SVG to be displayed. The resulting image reference is not accepted by Word, however.
Oh my... Microsoft is "inventing" again.
BTW. An example document would be nice to have.
Created attachment 153314 [details]
*.docx file containing an SVG using the `svgBlip` extension
Relevant snippet from `document.xml` inside:
<a14:useLocalDpi xmlns:a14="http://schemas.microsoft.com/office/drawing/2010/main" val="0"/>
<asvg:svgBlip xmlns:asvg="http://schemas.microsoft.com/office/drawing/2016/SVG/main" r:embed="rId5"/>
The example attached elicits the following behaviors:
* LibreOffice 18.104.22.168 -- PNG used (pixelated rendering at magnified views)
* Word 2010 (pre-extension) -- PNG used
* Word for Office 365 (16.0.11727.20244/13-Jul-2019) -- SVG used (smooth rendering at magnified views)
*** Bug 139516 has been marked as a duplicate of this bug. ***
Just encountered this issue with LO 7.1.4. Would be very cool if this could be fixed.
We are currently testing embedding images with Apache poi producing xlsx files and see the same behavior.
When we leave out the fallback-raster-grapic completely, LO shows nothing.