Use of images

MisterX b.xavier at internet.lu
Mon Jan 2 11:33:24 EST 2006


> It just came to me that you might be able to use the 
> alpha/mask data to secure images???
> 
> What would happen if each image had a copyright image done as 
> an alpha/mask with a regular image and then have rev remove it?

Actually it's much easier than that!

reparse the imagedata with a slight numeric mod in one or more channels
using differentials on colors and you got a footprint, just keep the two
hashes and if you find the copyright infringer, you just show the hashes...

there's lots of ways to make footprints, add sugar to your liking...

ok, it's a bit more complicated than that if you want to allow for image
resizing or cropping + any effects and still detect your watermark... but
not a lot but it's not perfect... the math is not hard but you do need to
know about number and Information Theory and play with statistics any
time... Using fractal image compression can help too...

You're idea to use the alpha-mask is genius but easy to detect or might me
easily saved in the wrong format without the alphamask (im wishing you a
fruitful world wide distribution of your program in 2006  ;) Adding
watermarks is not hard and lots has been written on it!

The key is to use the operators that are recognizable - despite image
changes like luminosity, channel edit, etc...  apply it to any color channel
(>1 channel recommended)... Sorry, I leave the fun of the search and script
to the hardyest of us that really want this... 

It should be doable in a few more versions of MoireX I think... ;) And
surely Willem color wonder stack will do it too ;)

what is sure is that creating the snapshot of the watermark, and writing it
directly into the image data or maskdata is medium easy... use the
baseconvert function like Chipp showed us for his image gradients (if my
memory serves me right)

here's another trick

Create two images, one with your image, the other with the watermark, make
one bitxor ink or blend into the other, take the snapshot and use that as
your new image!!! 

Computers can be complicated but why? Use rev!

hint: for the picture embedding math operation and Chipp's trick, use the
"baseconvert" function to rewrite the data.

Channel color interpolation functions available in MoireX... AltGradient has
them too... 

cheers
Xavier
http://monsieurx.com - not just taoo!


> -----Original Message-----
> From: use-revolution-bounces at lists.runrev.com 
> [mailto:use-revolution-bounces at lists.runrev.com] On Behalf Of 
> Thomas McGrath III
> Sent: Monday, 02 January, 2006 16:39
> To: How to use Revolution
> Subject: Re: Use of images
> 
> It just came to me that you might be able to use the 
> alpha/mask data to secure images???
> 
> What would happen if each image had a copyright image done as 
> an alpha/mask with a regular image and then have rev remove it?
> 
> Is this possible? Does rev or can rev handle the watermarks 
> made in Photoshop?
> 
> Has anyone done this?
> 
> Tom
> 
> On Jan 2, 2006, at 7:00 AM, xavier.bury at clearstream.com wrote:
> 
> > One solution to that would be to split up the images across a few 
> > stacks to reduce the memory footprint but still it would innelegant 
> > unless you want to secure your images so no one copies them...
> >
> > cheers
> > Xavier
> >
> 
> Thomas J McGrath III
> 3mcgrath at adelphia.net
> 
> Semantic Compaction Systems
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