Exported PDF missing image details

[Guest]

I just ran across a really strange issue when exporting a PDF from Affinity Publisher. I have a PNG image that contains a rendered drop-shadow (not a live effect) as seen in the original artwork (exported from Designer). Exporting this to a PDF (print or digital) results in the shadow disappearing visually (actually it appears to be rendered as a very subtle white haze if you zoom in). Doing the same test in InDesign works as expected, so I'm not entirely sure what's going on here.

An example Publisher file along with an exported PDF file have been provided.

alpha.afpub alpha.pdf

[User_783649]

Very interesting, Bryan. Same images in TIFF format exporting with shadows correctly. Seems like an issue with PNGs.

In APub:

Export to PDF:

[thomaso]

Strange, with your used PDF v1.7 (preset "for print"?) my ancient Acrobat reports an issue with the minimum required PDF v.1.4 …

… whereas it works if exported as PDF/X-4, though it reports a lower PDF version (1.6). But then the image gets compressed as JPEG – different to the zip/deflate compression with your PDF.

alpha_X-4.pdf

[Callum]

Hi Bryan Rieger,

When I export this file using the PDF x-1a:2003 preset the shadow effect looks correct. I imagine this is because this PDF standard flattens transparency. What happens when you try using this preset?

Thanks
C

test export x1-a.pdf

[thomaso]

13 minutes ago, Callum said:

I imagine this is because this PDF standard flattens transparency.

In contrast, it is strange that PDF/X-4 (attached above) exports the shadow correctly and without flattening, which is noticeable when you open the X-4.pdf in APub:

[User_783649]

15 minutes ago, thomaso said:

it is strange that PDF/X-4 (attached above) exports the shadow correctly

Why it is strange? PDF/X4 is based on PDF 1.6 according to specs and fully supports live transparency. PDF/X-1a is based on PDF 1.4 which supports transparency, but according to X-1a specs all transparency needs to be flattened.

[thomaso]

Strange because v1.7 doesn't work while v1.6 does, respectively a strange X-1 suggestion, assuming that flattening is not the wanted option for the OP.

[Guest]

1 hour ago, Callum said:

When I export this file using the PDF x-1a:2003 preset the shadow effect looks correct. I imagine this is because this PDF standard flattens transparency. What happens when you try using this preset?

Thanks @Callum exporting using the PDF x-1a:2003 preset does indeed render as expected.

Unfortunately this requires the user to understand far more about the various PDF versions and specifications than most casual users will have (or have patience for).

It's also strange (as @Alex M mentioned) that if I use a TIFF instead of a PNG it works as expected using the default print/digital export preset settings. I'm not sure what a fix for this might look like (or if it is indeed even broken), but it does result in a confusing user experience (compared to using InDesign) should someone run up against this issue using transparent PNGs (increasingly likely today via the web) in their workflow.

[User_783649]

@Bryan Rieger Actually X-1a doesn't look like a solution because according to specs transparency will be flattened (baked in). Once you will want to edit it you'll get the following:

[Guest]

@Alex M ah, damn… hopefully having the transparency baked will be okay with this project. I'm not sure anyone is going to edit the PDF after. Thanks!

[User_783649]

Now, the most interesting part. I made another file containing another PNG image and couple of transparent shapes. I also placed Bryan's PNG image there. Turns out everything exports just fine using default Print preset. The only thing that fails is Bryan's PNG icon.

test.pdf

test.afpub

Edited October 14, 2022 by Alex M
Replaced APub file (both images are embedded now)

[Guest]

7 minutes ago, Alex M said:

Now, the most interesting part. I made another file containing another PNG image and couple of transparent shapes. I also placed Bryan's PNG image there. Turns out everything exports just fine using default Print preset. The only thing that fails is Bryan's PNG icon.

The plot thickens. I have no idea what to do with that information, but it's interesting none the less.

 

[thomaso]

3 hours ago, Bryan Rieger said:

ah, damn… hopefully having the transparency baked will be okay with this project. I'm not sure anyone is going to edit the PDF after.

... you still have the option of PDF/X-4 which obviously does display the shadow of your .afpub but without flattening it.