On 6/11/07, Tijnema <[EMAIL PROTECTED]> wrote:
On 6/11/07, Robert Cummings <[EMAIL PROTECTED]> wrote:
> On Mon, 2007-06-11 at 10:38 -0400, tedd wrote:
> > Gnag:
> >
> > I know we can beat this thing to death, as we have in previous
> > threads and I don't anyone wants to travel previously traveled ground.
> >
> > However, Rob said:
> >
> > "A good captcha will try to exploit a computer's weaknesses."
> >
> > So, let's expound on that -- what do you consider to be a computer's
weakness?
>
> Well for instance as humans we can fairly easily recognize similar
> shapes. We can recognize an apple whether it is red, green, yellow, has
> a stem, has a leaf, is half eaten. A computer might recognize a circle,
> and might guess that the circle is an apple based on further analysis.
> But we as humans could recognize it as an apple even if we stretched it
> a bit so it was no longer circular, or as I said, if it was a crescent
> because someone had taken a huge bite out of it. This is something
> humans excel at... inferring information from similar previous
> experiences.
>
> Taking the image captcha to a different level, one could combine our
> ability to understand language as well as imagery. For instance we could
> have an icon repository of animals, vehicles, plants, etc (very obvious
> ones anyways). Then to create a captcha we could randomly select X
> icons, slightly morph them to spoof matching them within the captcha
> image itself, then ask:
>
> What animal do you see in the above picture?
>
> I think someone already said microsoft or someone does something
> similar. The principle is that we know what generally constitutes an
> animal and a computer does not. Similarly, an audio complement would be
> to have a background sound of maybe low level radio chatter overlaid
> with the sounds of various everyday items... then one could ask:
>
> What did you hear ringing?
>
> Possible answers... a bell, the telephone, an alarm, etc.
>
> The problem then becomes an issue of people who can't spell or are
> terrible at recognizing everyday things.
>
> Cheers,
> Rob.
Server builds up a database of pictures, client does the same with MD5
check, and problem solved...:)
Tijnema
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We're not talking about simply masking of the name of pictures
(apple.jpg, car.jpg, fat_slut.jpg, bench.jpg, etc.), but rather
morphing those images a bit. They'd still be recognized if skewed,
noise is added, and so on, but not as readily to a computer as a human
being (unless, perhaps, it's something like Robonova -
http://www.robots-dreams.com/2007/05/robot_image_rec.html).
--
Daniel P. Brown
[office] (570-) 587-7080 Ext. 272
[mobile] (570-) 766-8107
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