[dvipdfmx] bug with inclusion of a PNG

[Paulo Ney de Souza]

Indeed this PNG has an sRGB chunk and it exhibits the behavior we have
described -- when placed against a background of the same color it
displays a difference in tonality. I have previously said that XeTeX and
LibreOffice are doing the same thing, but that is not exactly correct, I'll
fix that below.

Behavior 1 - The included PNG shows a different tonality against a
background of the same color, when saved to PDF - on SOME (but not ALL)
output devices.
Program: XeTeX

Behavior 2 -  The included PNG shows a different tonality against a
background of the same color, when saved to PDF - on ALL output devices.
Program: LibreOffice

Behavior 3 -  The included PNG does NOT show a different tonality against a
background of the same color, when saved to PDF - on ANY device.
Programs: PDFTeX, LuaTeX, Adobe InDesign, Chrome, MS Publisher, MS Word,
Adobe Illustrator and Photoshop.

It seems to me that a PDF file with a CalRGB entry would have to contain an
ICC Profile in order to be PDF/X compliant. Would anyone be able to chime
on that?

Paulo Ney


On Thu, Jan 14, 2021 at 7:20 AM Shunsaku Hirata <shunsaku.hirata74 at gmail.com>
wrote:

> OK, I will send another one where an sRGB chunk was added to
> A.png by TweakPNG program.
>
> Thanks,
> Shunsaku Hirata
>
> 2021年1月14日(木) 22:48 Philip Taylor <P.Taylor at hellenic-institute.uk>:
> >
> > Shunsaku Hirata wrote:
> >
> > Do you have a PNG that any of these tools report an sRGB chunk?
> >
> > I have created a PNG file that has a sRGB chunk. (Same image as
> > A.png but just sRGB chunk added)
> >
> >
> > Confirmed, but I have an odd feeling that some other chunks seems to
> have disappeared ...
> >
> >
> >
> >
>
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