Apache-Talk @lexa.ru 

Inet-Admins @info.east.ru 

Filmscanners @halftone.co.uk 

Security-alerts @yandex-team.ru 

nginx-ru @sysoev.ru 

   


   


   















      :: Filmscanners
Filmscanners mailing list archive (filmscanners@halftone.co.uk)

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[filmscanners] Re: Disabling right-click,etc. (was: Webhomepagewriting software)



Arthur writes:

> There are a number of watermarking systems
> that embed a code into the image that is not
> visible to the viewer.  Digimarc is one.

All watermarking systems degrade image quality, no matter what Digimarc
claims.  It is a consequence of information theory (again), and cannot be
avoided.

> The encrypting has been improved quite a bit
> over the years so that cropping and blurring
> or resizing will not confound the coding or
> reading software.

It is always possible to remove digital watermarks.  Again, this is an
unavoidable fact, irrespective of Digimarc's claims or anyone else's.
Indeed, there is an inverse relationship between the degree of degradation
of an image caused by a watermark and the ease with which the watermark can
be removed; in other words, a watermark that is difficult to remove is also
easy to see, and vice versa.

> Further, although even though these codes are
> supposed to survive printing and scanning,
> anything not connected to the web would be pretty
> hard to track down.

Watermarking is mstly useful only after you're in court, trying to prove
that an image is really yours.  Of course, if you scanned film, it's easier
just to produce the original negatives or slides.

----------------------------------------------------------------------------------------
Unsubscribe by mail to listserver@halftone.co.uk, with 'unsubscribe 
filmscanners'
or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or 
body



 




Copyright © Lexa Software, 1996-2009.