Archive for September, 2007

Witango reCAPTCHA component

Friday, September 21st, 2007

A CAPTCHA is a program that can tell whether its user is a human or a computer, often by having the human interpret words that are visually distorted beyond the ability of computerized Optical Character Recognition system.

On Raise the Bar Press, the web site for my wife’s book, “Doublethink: A Tale of Unintended Consequences,” there is a form for general inquiries that has been discovered by form bots,, generating bogus inquiries that are hard to filter as spam.

To put a stop to this I needed a CAPTCHA. A quick search led me to reCAPTCHA, which uses images from old books as the challenge.  The human response helps to confim the optical character recognition of the old text, thereby digitizing, in addition to allowing human verification for the form submittal.  The API looked simple, and I could get an api key for free, so I gave it a try.

I downloaded a php example and recoded it as a witango component. It was a quick project that I thought would be useful to others, so I’ve open-sourced my port.