Am Tue, 30 Apr 2024 11:00:44 +0300 schrieb Linas Stonys:
> I get different colors of png image (attached europe.png) when I
> compile lualatex and pdfflatex.
> Image contains some "transparency group".
> Differences are seen in acrobat but pdfxchange and sumatra shows the
> same (normaly like pdflatex did)
> Could luatex load png like pdftex does?
You can add the Group key to the current page with
\pdfvariable pageattr{/Group <</S /Transparency /I true /CS
DeviceRGB>>}
or if you use the LaTeX pdfmanagement (with \DocumentMetadata{})
with
\ExplSyntaxOn
\pdfmanagement_add:nnn{ThisPage}{Group}{<</S /Transparency /I~true
/CS /DeviceRGB>>}
\ExplSyntaxOff
pdftex adds that automatically if it detects a png with
transparency, but on the whole I prefer the luatex method, as there
is less danger that you end up with duplicated Group entries.
BTW: Adobe reader only shows a difference if you have set in the
preferences -> page display "Use overprint preview" to "always" or
to "automatic".
--
Ulrike Fischer
http://www.troubleshooting-tex.de/
