[thelist] Security code images

Richard Davey rich at launchcode.co.uk
Tue Aug 3 09:12:34 CDT 2004

Hello Jono,

Tuesday, August 3, 2004, 3:01:10 PM, you wrote:

J> That means that an image (png) appears, and as far as I know, "machines"
J> cannot read images, only text.  I am only assuming here.  Am I way off on
J> this?

>> Interesting article. It intrigued me enough to play a bit. I can't
>> quite come up with the best way to distort the image to make it
>> difficult to read by machines. I tried arcs and dashed lines, both
>> with some degree of random placement.

There is another way - instead of scrambling a code and telling the
user to "type in what you see" - you could show a picture, of say 3
rabbits and say "how many rabbits do you see?". The user types in 3

It's a simple example, but you can see the subtle difference. No
script could ever accurately determine what is or isn't a rabbit in a

Needless to say, they don't have to be rabbits :)

Best regards,

Richard Davey
 http://www.launchcode.co.uk - PHP Development Services
 "I am not young enough to know everything." - Oscar Wilde

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