[Digikam-users] How to apply digital watermark

[Sherwood Botsford]

On water marks.  I wanted to ghost my logo onto the image, as if lightly
frosted on glass.  The Decorate doesn't allow you to do this,.

On protection:
One form of protection when it comes to court would be the existence of
other pictures from the same shooting session, uncropped originals from the
same session.

I figured that one way to protect an image would be to  overlay a 1 least
significant bit fractal design over it.

The design needs to have broad elements, so that a casual smoothing or
resizing doesn't destroy it.  It also needs to have fine scale elements so
that it's
still recognizable when severly cropped.    In ascii art this is a 2 level
example for Sherwood's Forests Tree Farms



SFTFS  FTFSF SFTFSF FTFSF
S      F       T    F
S      F       T    F
SFTFS  FTFS    T    FTFS
    S  F       T    F
    S  F       T    F
SFTFS  F       T    F


Probably some work could be done to match the method to the style of file
(E.g seems that a lot of jpeg stuff happens in multiples of 8? So parhaps
putting
it on an 8 boundary will make it more persistent.

Working at multiple levels of detail makes it a lot more difficult to edit
out.


On Sun, May 3, 2009 at 9:49 AM, gerlos <gerlosgm at gmail.com> wrote:
>
> On domenica 03 maggio 2009 17:05:44, Gilles Caulier wrote:
> : > 2009/5/3 libu <lb.mailinglists at gmail.com>:
> > > Yup, that it is :) ! Thanks m. !
> > >
> > > Do you know whether we can do this in a batch instead of 1 photo at a
> > > time.
> >
> > Implemented in digiKam 0.11.0, where a new Batch Queue Manager have
> > been added. A Batch tool can add visible Watermark...
>
> Another nice thing to have is "invisible" watermarking, maybe including a
> "signature" through steganography, so a photographer can protect himself
from
> abuse of his work: if you can see the watermark, you could also remove it
> (most times just cropping the image!).
>
> Unfortunately, it seems that's there are really few tools to do these
things
> released under GNU GPL...
>
> http://en.wikipedia.org/wiki/Digital_watermarking
> http://en.wikipedia.org/wiki/Steganography
> http://steghide.sourceforge.net/
> http://stegui.sourceforge.net/
>
> best regards
> gerlos
> _______________________________________________
> Digikam-users mailing list
> Digikam-users at kde.org
> https://mail.kde.org/mailman/listinfo/digikam-users



--
Sherwood Botsford
Sherwood's Forests
Warburg, Alberta T0C 2T0
http://www.sherwoods-forests.com
780-848-2548
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