Mayayana wrote:
"pyotr filipivich" wrote

| Not so much "hides" as substitutes not enough to be "noticeable"
| to "casual inspection." How many "bad pixels" can you have before the
| picture "fails" as an image.
|
Seems a bit farfetched. I suppose it might be OK
in a large image, but when numerous pixels bear
no resemblance to the contiguous pixels, that's an
oddity. Hopefully they're not being used to send
nuclear codes and only things like, "Don't forget mustard
with the President's Happy Meal".



You can see the dot density.

https://en.wikipedia.org/wiki/Machin...ntermarkrp.jpg

This one shows you the print mechanism is not bashful about it.
They don't change the color of the dots to reduce visibility.

https://www.heise.de/newsticker/meld...n-4090876.html

You can read that in English, here. Kinda amusing.

https://translate.google.com/transla...n-4090876.html

"Timo and Stephan examined 1,286 printouts from 141 printers from 18 different manufacturers"

I'm guessing they were bored at the time. That's a lot of yellow dots
to stare at. I suppose next we'll see "and Timo and Stephan
made $7 million using an ordinary inkjet printer" :-)

Now, overreach, would be if that dot pattern was spotted on
a *black and white* printer, where there is no chance of
currency counterfeiting.

This is their toolset - presumably to be used if you scan a color
laser printer document, and want to anonymize it before re-printing
on your own office printer. So the original document cannot be tracked
to its printer.

https://github.com/dfd-tud/deda

Paul