On Sat, May 30, 2009 at 12:14:14PM -0600, David Green wrote:
> On 2009-May-30, at 12:06 pm, David Green wrote:
> >...what "Perl6" is today, let alone what it will be tomorrow.
> Actually, we do kind of know what Perl will look like a decade from  
> now, because P6 is deliberately extensible enough that we may never  
> need a Perl 7.  But that simply means that holiday photos are already  
> a possibility:
> perl -MSteganography::Images pics/2009/ceylon.jpg
> In fact, you could do that in Perl 5....

Storing things in PNGs has already been done, badly, by
Acme::Steganography::Image::Png :-)

Well, badly as far as the "hiding" bit goes. The effectiveness of the Floyd-
Steinberg dithering actually surprised me.

There's "real" software to do real steganography within JPEGs, that I think
stated that it managed to use up to 1 bit in 9 without being obvious. I think
that you'd have to understand the JPEG file format to make it work
effectively, and I didn't need to do that to prove my point.

(Which was that a photo sharing site with no file quota was not a good idea as
it could be abused by third parties to completely externalise their file
distribution costs)

Mmm, I realise that this also means that I've had a JPEG file on CPAN for
4 years now, and no-one has commented :-)

Nicholas Clark

Reply via email to