Save PDF from PowerPoint (.pptx) with transparent background

Question

I am doing a presentation with Beamer and I want to use some pictures I've made for an old PowerPoint presentation.

The way I am doing it now is:

1. I put each figure in one slide, then I save the whole .pptx in .pdf format
2. I use pdftk to separate the slides in different files
3. I use pdfcrop for each of these files to trim the empty areas out

The problem is that I am putting these .pdf files in a document where the background is not white, and they were saved as white, not transparent

I've tried this with no success. Maybe there would be a built-in PowerPoint option or any other utilities for making it transparent since the .pptx conversion phase?

Solution

I had the same issue and found that selecting the figure and using the Save As Image approach detailed in this SO answer produced incorrect results when the output format is set to PDF (using Office for Mac 2016).

The workaround I found was to post-process the PDFs with Inkscape in the following way:

1. open the pdf in Inkscape
2. select everything with Ctrl+a
3. hit Ctrl+Shift+g repeatedly to ungroup the elements in the PDF
4. deselect everything
5. select the background layer and delete it
6. Ctrl+s to save the PDF again

Comments

[DavidPostill]

Does this help? OfficeOne TransparentShow 3.0 - TransparentShow can make a particular color of the slide show transparent. The regions where the slides have the specified color are replaced by the contents on the desktop.

[DavidPostill]

Stack Overflow duplicate PPT to PNG with trasparent background

[gsmafra]

"The regions where the slides have the specified color are replaced by the contents on the desktop". It seems like a plugin only for presentations, not for exporting

[DavidPostill]

You won't know till you try it ;). It does say "Click the Save Settings button to save the transparent color setting with the presentation itself." so it may work when exporting. In any case the Stack Overflow link should be looked at.

[gsmafra]

About the SO question, I guess the possible workarounds would be different depending on what file format you want. He asks for a .png conversion and that is what the answer delivers. I cannot do the same thing and get a .pdf or any other vectorized format

[DavidPostill]

You can make a pdf out of multiple png files.

[gsmafra]

AFAIK once you convert a vectorized object to a raster image there is no way you can "recover" the previous quality, which is exactly the point of wanting a pdf

[DavidPostill]

<shrug> time for you to do your own research.