PowerPoint 16.19 (MAC) Save as PDF lose true colors - Mojave

Luis,

I was a little too optimistic when I wrote that your file gave no problem. When you open it in preview and select export as PDF, then you should compare the color of the original PNG file and that of the PDF and observe that the blue color in the PDF is mixed with grey. If you would increase the transparency of your blue box in the PNG much more, you will observe that the color in the exported PDF will become more grey. Inseting your PNG in a Powerpoint or Keynote presentation and converting to PDF gives the same problem. So back to square one !

The only workaround I found with Powerpoint slides containing PNG images with transparency who give grey color when converted to PDF, is first to export that whole slide as PNG (it then includes the background of the slide) and then insert that PNG in the problem slide before converting to PDF.

Hence the problem is only with PNG images with transparency features on a transparent background, so that solves it.

Your suggestion of opening the PNG in Preview and saving it again as PNG only works if you uncheck te Alfa checkbox, but then you lose the transparent background, and that is not a solution when you want to use that image in a document.

Rogier.

Arturo,

This is a Mojave problem , rendering transparancy in images when saving as PDF or printing. If you have e.g. a PNG image with tranparancy in your presentation the background color will be grey in the PDF file or in the print. I do not know if this will be solved in the next release. It is not a Powerpoint problem. A PNG file with transparancy saved as PDF will also have the same problem. The only workaround for the moment is not to use transparancy in your presentations.

Just updated to Mojave 10.14.4 and happy to notice the problem is solved !!

How were these png files created?

Using your files I do get grey output in pdf, but I can create similar png files, with transparency, in my mac, and they do NOT suffer from this problem.

See if you also get the same problem with this file:

https://www.dropbox.com/s/blckoi1cxb5d0xx/shape-with-transparency.png?dl=0

Thanks for the test. It seems you are pointing at MS Office for the problem with transparency when exporting to PDF.

As I mentioned, I use Office 2016 version 16.16.8 (as of this morning) as a one time purchase package and do not intend yet to upgrade to 2019. It may well be that Office 2019 now uses its own PDF export code to solve the problem.

However, when I use Keynote version 8.3 or Notes version 5.3 and insert a PNG file with transparency, and then export it as a PDF I have the same problem that the transparent parts without background are colored grey. The PDF file is version 1.4. So no MS Office involved.

Same happens when opening that same PNG file in Preview and exporting as PDF. Again version 1.4.

So the problem is still with Mojave. I am on version 10.14.3. latest update.

The problem has already been reported in the discussion Transparent Images Printing Gray in Word Docs and the workaround is to save your png files as jpeg before using them in Word or Powerpoint. However then you lose the transparency capability.

Try creating a form in word or powerpoint, e.g. a rectangle, use fill solid color with 50% tranparency and it will save ok as a pdf, however if you select fill with color transition and transparency and save as pdf it will come out gray. The pdf file version is 1.4.

Also try to create a form in word or powerpoint with solid fill and transparency or color transition and transparency, and save the figure (not the slide !) as a png image, and reintroduce that png in your word or powerpoint document an then save your document as a pdf, then in both cases the picture will come out gray !!

By the way any png image with transparency, be it created with an office document or with keynote or with inkscape or dowloaded from the web, etc.., will come out gray when saved as pdf as part of a document, and even just saved as pdf with the preview app.

Then there is something else involved, probably specific to your system. I cannot reproduce it in Keynote or Pages either.

You may want to run Etrecheck and post its report here so we can look for possible causes.

Could you post an example ppt file that shows the problem, to a place like dropbox, so we can test?

Did you try this with the most recent updates to the OS and MS Office (16.22)?

I have just tried adding png images with transparency to a Word document, saved it as PDF and it did NOT have this problem.

I do not have any Microsoft products installed. I tested from Pages v7.3, and that gave a PDF v1.3. document. LibreOffice uses their own PDF library, not Apple's so I didn't use it for the test.

When you open that PDF v1.4 in Preview, and select information, does it say:

PDF Producer: macOS Version 10.14.3 (Build 18D109) Quartz PDFContext

I created the file I posted using Pixelmator.

I will try a few more variations tomorrow, like creating in Keynote as you mentioned.

I wonder if the following works for you: take the png files that exhibit the problem, open in Preview and then save copy as png again. Maybe this new file will be ok. I can’t test right now as I am not at my mac but will try that also in the morning.

This are the PNG testfiles

Afbeelding1.png

Afbeelding2.png

Just insert them on a blank slide in Keynote and then export them as PDF

This is how the PDF's look on my system

Naamloos.pdf

Naamloos2.pdf

"Because I an not the only one having the problem, I would like to send you two PNG test files to insert in a Keynote presentation and then export to PDF. How can I get them to you?"

I suggest you upload them to some place like dropbox, and post a link here.