On Mon, 19 Jun 2017 12:21:00 +0200 luigi scarso <luigi.scarso@gmail.com
> wrote:

> With poppler 0.55,
> I am able to reproduce it with
>
> $ convert -size 100x100 radial-gradient:  rgradient.jpg; convert
> rgradient.jpg rgradient.pdf
> $ cat test.tex
>
> \starttext
> \externalfigure[rgradient.pdf]
> \stoptext
>
> Syntax Error (623): Unknown filter 'DCTDecode'
>
> I'm investigating
>
> --
> luigi
>

Thank you Luigi,

This error message is gone now. Sorry for the confusion I have created by
not having reported a well defined way to produce this message.

Cheers, Christoph