🚀 go-pugleaf

In message <b51oac$q2b$1@news8.svr.pol.co.uk>
   "Duncan" <duncansmith99@hotmail.com> wrote:

> I was thinking of providing information, in my small business, on CD
> but am worried if the photos and other files are copied.
> 
> Is there anyway I can make my CD's such they are impossible to copy in
> total or even the odd files.

As Amethyst has pointed out there are ways of protecting the individual
images, however, a determined user can still remove even the most subtle
watermarks, I've done it myself, the watermarks typically rely on 'hidden'
information, ie colours and tints that the human eye doesn't normally see,
this does rely on having a certain range of colours available, so,
converting the image into a low colour format with bilinear dithering and
then back again can result in a cleaned image that looks identical to the
original but which has lost its watermarks.

See http://www.sarpcuser.fsworld.co.uk/colours/ for an example of a 24bit
(16 million colours) image and the same image in just 8bit (256 colours).

It may take a while to download, the images used are PNG rather than JPG,
this allows for verification that the images are the colour depth that
they say they are. 2 images 503,432 bytes and 188,612 bytes


As to protecting the CD itself, there are ways of making it hard to copy,
but, I've found that the methods used to protect the disc often mean that
some people can't even use the disc. And there are programs that can
'bitcopy' the CD, so, short of burning a hologram into the CD it's not
really possible to make a CD that is uncopyable.



The best thing you can do is to put an obvious copyright marker on every
image, your company logo perhaps, across the centre of the image as a
translucent mask. 
eg http://www.sarpcuser.fsworld.co.uk/colours/sa09-w.jpg


-- 
To contact me please use email(at)sarpcuser(dot)fsworld(dot)co(dot)uk