Transparency gradient on transparent PNGs not working in PDF 1.6

Previous topic - Next topic

Wescrop

Hi,
today I came across an issue, but I don't know if this is a bug or a not implemented feature:

Is use a PNG image with transparent background. I add transparency of 30% to the whole image. After PDF-export 1.6 the PDF shows the image correctly with 30% transparency.

Now I change the transparency to linear gradient transparency, one side 100%, the other 0%. Looks fine in Scribus, but after PDF export there is no linear gradient transparency at all, the whole image has 100% opacity.

With JPGs this works fine, it also works fine with full image transparency, but not with linear or circular gradient transparency on PNGs.

I did not find any thread about this, so did I do something wrong?

Thanks for any help.

PatJr

not helpful, I know, but I would just use gimp for any image editing

Wescrop

Thank you. Yes, I already did this workaround, but I was not sure about this issue. Bug or (no)feature?

a.l.e


Wescrop


a.l.e

the attached pdf seems to look like the right image in my browser...

gradient.png

Wescrop

Quote from: a.l.e on May 08, 2023, 07:01:15 PMthe attached pdf seems to look like the right image in my browser...

Thanks. You are right. When opening the PDF in my browser it looks fine. When using Foxit (which I use a long time) it is not transparent. So is this a Foxit-Bug and not by Scribus? I am not sure. Never had such issues before.

Wescrop

I installed Acrobat Reader and it also does not show the transparency. So it is not a Foxit issue. What's the cause, any idea?

When using full image transparency of e.g. 30% it works, but when using linear gradient transparency for the png the generated pdf has no transparency in Acrobat and Foxit. But Firefox shows transparency correct, Edge does not.

AdmFubar

Tried this in Okular and have the same issue. Opens fine in Waterfox browser. Seems to be an issue with certain pdf viewers and not Scribus' pdf's.
Using Scribus 1.5.8 + 1.6.1, openSUSE 15.5
Advanced hobbyist

a.l.e

ok, it seems that somewhere there is an issue...

mupdf and evince do not show the gradient either.

i've tried to use pdf 1.4 and i also get a wrong gradient in there.

could you try acrobat reader with a pdf 1.4?

and would you mind filling a ticket in https://bugs.scribus.net with the .sla file, the .pdf file and the list of browsers / pdf viewers that show or not correctly the pdf?

Wescrop

Quote from: a.l.e on May 09, 2023, 08:25:42 AMand would you mind filling a ticket in https://bugs.scribus.net with the .sla file, the .pdf file and the list of browsers / pdf viewers that show or not correctly the pdf?
I made a bug report. Thank you.

https://bugs.scribus.net/view.php?id=16940