Invisible digital watermark

[Gilles Caulier]

Simon,

Photoshop have a tool to watermark photo before to publish this on the
web. It's in relation with a web service to identify a copyright photo
everywhere though the web.

Of course the service is not free...

https://www.digimarc.com/application/photography

Gilles

2017-05-12 18:16 GMT+02:00 Simon Frei <freisim93 at gmail.com>:
> I don't know anything about how it works, I just had a hunch that this
> would be something that could be in G'MIC - and it was. You best ask the
> G'MIC folks about it.
>
> Honestly, I don't really consider this very useful in the real world.
> The party where you proclaim a copyright breach has to use G'MIC digiKam
> to recover the copyright information, which they probably won't, and a
> simple proof of ownership by comparing to an "original" (higher res,
> raw, ...) picture is probably sufficient. If your picture is that
> valuable, the "thief" will probably also go trough the trouble of
> removing your notice from the fourier domain (which probably is
> possible, as it is fourier and the original transformation
> implementation is known).
>
> On 12/05/17 15:17, Sveinn í Felli wrote:
>> Maybe something similar to image steganography could be used?
>> That is a process where one can embed encrypted message/image into a
>> picture. Pixelknot is such an OSS-application for Android, see
>> <https://guardianproject.info/apps/pixelknot/>
>>
>> Simon, do you know how well the Fourier markings survive through
>> modifications by image sharing services?
>>
>> Regards,
>> Sveinn í Felli
>>
>> Þann fös 12.maí 2017 12:38, skrifaði Louis A. Turk:
>>> On 05/12/2017 07:05 PM, Gilles Caulier wrote:
>>>> Very interesting. Please comment this entry in bugzilla accordingly :
>>>>
>>>> https://bugs.kde.org/show_bug.cgi?id=268981
>>>>
>>>> Thanks in advance
>>>>
>>>> Gilles Caulier
>>>>
>>>> 2017-05-12 12:03 GMT+02:00 Simon Frei <freisim93 at gmail.com>:
>>>>> There is a G'MIC filter that embeds text in the fourier domain, it is
>>>>> called "Fourier watermark" (and "Fourier analysis" to retrieve the
>>>>> info): https://gmicol.greyc.fr/
>>>>>
>>>>> On 12/05/17 11:35, Gilles Caulier wrote:
>>>>>> You cannot. Invisble watermark use wavelets encoding methods which
>>>>>> are
>>>>>> patented in US and impossible as i know to code in open source...
>>>>>>
>>>>>> Best
>>>>>>
>>>>>> Gilles Caulier
>>>>>>
>>>>>> 2017-05-12 10:42 GMT+02:00 Louis A. Turk
>>>>>> <louisaturk at firmanelohim.org>:
>>>>>>> How can I do invisible digital watermarking with digikam5 as
>>>>>>> mentioned
>>>>>>> here:
>>>>>>> https://docs.kde.org/trunk5/en/extragear-graphics/digikam/using-dam.html#using-dam-copyright
>>>>>>>
>>>>>>>
>>>>>>> How can I do a regular watermark?
>>>>>>>
>>>>>>> drl
>>>>>
>>>>>
>>>
>>> Thank you Gilles and Simon. Hopefully, the impossible may be possible
>>> after all.
>>>
>>> drl
>>>
>>
>
>