[ NNSquad ] Re: Making JPEG Images Copy-Evident

[Barry Gold <BarryDGold@ca.rr.com>]

On 2/7/2011 9:31 AM, Lauren Weinstein wrote:
> Making JPEG Images Copy-Evident
>
> http://bit.ly/hFBAZ6  (ThreatPost)

Huh?  Exactly what do they hope to accomplish with this?  Contrary to 
the headline, this doesn't detect _copying_.  It detects the particular 
case of decompressing the image, then recompressing with a particular 
"quality" setting.

I dunno, maybe there are websites that do that routinely -- accept 
uploaded images, and recompress them to a lower quality to save disk 
space.  But disk is so cheap nowadays, why would anybody bother 
recompressing individual images?  Videos, I can see, they still take up 
a lot of space.  But images?  Really?

Or let's take another example:  Somebody takes your image, converts it 
to a lossless format like png or bmp, and makes changes -- crops it, 
adds captions, whatever.  Then they recompress it to jpg, and the 
"copy-evident" text becomes visible: "THIS IMAGE HAS BEEN COPIED WITHOUT 
PERMISSION OF THE COPYRIGHT OWNER" or whatever.

So the user looks at his image (everybody looks at their websites before 
they release them to the public, don't they?), sees this highly obvious 
text, and says, "oops! better try something else."  And they re-release 
it at a higher or lower quality, or better yet as a png with lossless 
compression.

Still, it shows somebody is at least _thinking_ about "copy protection" 
of images, even if this particular item is a solution in search of a 
problem.