[shutupalready]

Your final demo is easily defeated because a link to cat.png appears right in the page source:

I mean this line:

<img id="cat" src="cat.png" width="237" height="235" />

in the source code to this page:

  http://www.patrick-wied.at/talks/image-protection/demos/demo-interlacing.html

Am I correct in assuming that for demo purposes you didn't worry about that, but if you had intended to do this in practice, you would have to feed the data in cat.png to client in some non-obvious way?

[pa7]

Yes you are right, the main purpose of the last demo is to try to prevent a screen shot (ignoring all other techniques to obtain the image). thank you I, already forgot about it and will change that