Image based steganography that survives resizing?

[mick at pauldotcom.com (Michael Douglas)]

Jim you hit the nail on the head...  you can be VERY creative with how
you hide bar codes.

I'm unable to find the example, but I saw a freaking amazing one that
was done as background element... but before you yawn...  it was
hidden as shadows to someone's hair!  I can't believe I can't find
this...  grr.   (any cloud source help?)

I'm sure there's other good examples to be found too.


- Mick


On Wed, Jan 27, 2010 at 11:56 AM, Jim Halfpenny <jim.halfpenny at gmail.com> wrote:
> If you do not require an optical scanner then I guess a barcode could look a
> lot less like a traditional black and white one, so making it harder to
> detect with the naked eye. If you divide each bar into a %age of the image
> width and use the largest RGB component value then you could have a
> multi-colour barcode with some tolerance to resizing. Shrinking is obviously
> going to reduce the amount of information and may be lossy but enlargement
> ought to be OK.
>
> Jim
>
> 2010/1/27 Adrian Crenshaw <irongeek at irongeek.com>
> > Bar codes could work, but I want only the computer to see the stego, not a
> > human. If I use a barcode, won't it show to the user?
> >
> > Thanks,
> > Adrian
> >
> > On Wed, Jan 27, 2010 at 10:47 AM, Rob Fuller <jd.mubix at gmail.com> wrote:
> > > Agreed about the EXIF data, but are you only talking about binary
> > > steganography? You can hide barcodes in images pretty simply that
> > > would survive resizing just fine. Also, are you talking human or
> > > computer legible stego? Peoples choice of stego is highly dependent on
> > > message size,message contents, repetition, and placement.
> > >
> > > --
> > > Rob Fuller | Mubix
> > > Room362.com | Hak5.org | TheAcademyPro.com
> > >
> > >
> > >
> > > On Wed, Jan 27, 2010 at 7:42 AM, Jim Halfpenny <jim.halfpenny at gmail.com>
> > > wrote:
> > > > Image metadata may survive (EXIF, copyright strings), it really depends
> > > > on
> > > > how the program manipulating the image handles the image and metadata
> > > > parts
> > > > of the file. Chances are if the hidden data is in the image data then
> > > > it
> > > > will not survive resizing, changes to colour deptt, colour maps etc.
> > > >
> > > > Jim
> > > >
> > > > 2010/1/27 Adrian Crenshaw <irongeek at irongeek.com>
> > > > > Hi all,
> > > > > ??? Does anyone know of any image based steganography that survives
> > > > > resizing of the image? I'm looking into using blind drops, but many
> > > > > sites
> > > > > alter images that they post.
> > > > >
> > > > > Thanks,
> > > > > Adrian
> > > > >
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