On Thu, May 16, 2019 at 02:40:07PM +0200, Hans Hagen wrote:
> On 5/16/2019 12:21 PM, Rudolf Bahr wrote:
> > The problem with artefacts in .png images is still unsolved for me.
> > I can circumvent it by using .jpg or .tiff images instead of .png images
> > as long as no transparent areas in the images are needed. As far as I know
> > .jpg and .tiff formats cannot handle transparancy, do they?
> > 
> > Now in .log files messages like
> > "luatex warning  > pdfe: invalid 11 0 R object at offset 223611"
> > can be seen. Please, what do they mean?

> Does that come from an pdf generated by image magick>? If so, the problem is
> there ... the last years I've seen lots of converted files with bogus pdf
> objects. (Kind of harmless but still.)
> 
> Hans


No. I never use neither ImageMagick nor GraphicsMagick to generate images in
.pdf-format. Even with my scanner software I produce always .jpg-images though it
is capable to produce .pdf-output too. The only .pdf-files I'm doing are made by
ConTeXt-LMTX!

I shall append another, interesting MWE. There is a .png-image which is, as it
occasionally happens, represented as it should, by ConTeXt. And then the same .png-image
to which I added a red frame by GIMP2.10. This one shows artefacts in ConTeXt!

I'm adding the .log-file too. There again is a luatex-warning, as I could observe them
often in ConTeXt-LMTX:

--------------------------------------------------------------
luatex warning  > pdfe: invalid 11 0 R object at offset 385741
--------------------------------------------------------------
Please, what does mean it? I fear there is something wrong with the .png-handling
of ConTeXt/luatex.

The outputs of
feh image----red-frame.png
gm display image----red-frame.png
are looking ok. And GIMP2.10 has produced all image-files.

Rudolf


PS.:
echo $PATH
/home/sam/Android/platform-tools:/bin:/usr/bin:/home/sam/context-lmtx/tex/texmf-linux-64/bin:/home/sam/context-lmtx/bin:/home/sam/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games

R.