For your reference, records indicate that
Stefan Claas <pollux@tilde.club> wrote:

> Yes me too, but how if one embeds the vector graphic in another .svg file
> like an invisible watermark (a transparent object). Maybe worth to
> explore?

Once you just start jamming data into “out of band” spaces in file formats
it doesn’t feel as interesting an exercise. It’s also a big red flag to
anyone who *is* suspiciously inspecting the contents.

> https://github.com/japplebaum/svgsteg

I’ve also never been a big fan of using only one bit of each number like
that. To my thinking, it doesn’t make much sense to have an
“imperceptible” difference to some reference file, because that inherently
introduces a possible validity check. “Nice image of Tux you’ve got here.
Any reason it doesn’t hash to the publicly available version that everyone
else uses? Let’s continue this investigation in a more formal
setting . . .”

I was thinking of something that used as many bits as possible. The
“image” may render more like a Jackson Pollock painting or some other
abstract artwork, but the numbers/data there in plain sight, and *meant*
to be seen, so you couldn’t be accused of hiding anything. I mean, yeah,
they could just as easily lock you up if they wanted to, but I think the
plausible deniability is greater when the data is as unstructured as
possible.

--
"Also . . . I can kill you with my brain."
River Tam, Trash, Firefly

Doc O'Leary , wrote:
> I was thinking of something that used as many bits as possible. The
> “image” may render more like a Jackson Pollock painting or some other
> abstract artwork, but the numbers/data there in plain sight, and
> *meant* to be seen, so you couldn’t be accused of hiding anything. I
> mean, yeah, they could just as easily lock you up if they wanted to,
> but I think the plausible deniability is greater when the data is as
> unstructured as possible.

I tried with colored rectangles, but then when decoding not all data
was written. I then changed to circles with a random fill color and
black border and now it works. The program tells the user that the hex
input string must be of even pairs (for x,y coordinates) and if odd it
prints an error message to stdout.

Regards
Stefan
--
----Ed25519 Signature----
8a209aa55569ace635554dbde9cd94947e044bd65255949e66218b70e8f6aa80
e4e4325180b6f1d1de24c0cb7573f916f771dc1739f9c0a8b6ef9a1e9bc6be08

Stefan Claas wrote:

> I tried with colored rectangles, but then when decoding not all data
> was written. I then changed to circles with a random fill color and
> black border and now it works. The program tells the user that the hex
> input string must be of even pairs (for x,y coordinates) and if odd it
> prints an error message to stdout.

Sample output:

(The encoded message is: Zwölf Boxkämpfer jagen Viktor quer über den
großen Sylter Deich.)

Usenet Group: de.alt.dateien.misc
M-ID: <us4su4$3832i$1@stefan.eternal-september.org>

Regards
Stefan
--
----Ed25519 Signature----
9b1ae01a38e1f532c50f6033a77ba0acf2272bfe26398e5c0b71770f22c2d772
007345c1bc5a9a7544a1e56d1fb0da3831a2a5c7100d1781bcb8b5327c4f7c04