Maybe no stego on eBay afterall

[Hadmut Danisch]

On Fri, Jul 19, 2002 at 09:01:16PM -0400, Peter Wayner wrote:
> 
> I used to think that CCD cameras were a pretty good approximation of 
> random number generators, but not any longer. I've seen too many 
> pictures where the LSB is heavily correlated with some of the higher 
> order bits. Really. There are some good pictures documenting in my 
> book. So while I think you're making a fair point, experience doesn't 
> always suggest that it work out that way.

Of course. If the LSB wouldn't correlate to the higher order
bits in any way, they definitely wouldn't contain image information
and the camera would do a better job to simply cut them away.

Latest cameras use a higher resolution than just 8bit, so the
LSB of the image file isn't the LSB of the image anymore.

Another reason is the interpolation done by the camera (maybe the
LSB of the Foveon chip should be tested). And maybe the JPEG encoding.
Did you check any raw images?

On the other hand, even some of the latest and best cameras are
known to suffer from high image noise (e.g. Minolta Dimage 7i).
There is a software known to be quite good in removing this
noise (www.neatimage.com). Unfortunately, the source is not available.

But since these guys know pretty well how to remove this kind of
noise, they maybe know how to add some and make it look native.

regards
Hadmut



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