Human validation with an image

[Aahz]

In article <2ca51434.0402181235.460befe3 at posting.google.com>,
DrPike <ml71 at katamail.com> wrote:
>
>The problem: I need to manage thousands of registration form for an
>incoming congress, and I need to avoid spambots.
>
>The idea should be to send a light image containig an alphanumeric
>string, with a bit of manipulation (eg. bkground noise, distortions
>and so on) in order to make a possible interpretation by humans but
>programs.

With thousands of registrations, you're going to have at least a few
blind or visually-impaired users.  Bad move.  Instead, ask a question
that requires intelligence to answer.  (E.g. "What color is the sky?" or
"What is the third word of the second paragraph?" or "Give me the first
letter of each word of the following phrase: spam and eggs")
-- 
Aahz (aahz at pythoncraft.com)           <*>         http://www.pythoncraft.com/

"Argue for your limitations, and sure enough they're yours."  --Richard Bach