I’ve been playing around with generating “captcha” images from PHP. Captchas are those Turing-test images used to screen out bots — the image contains text that a human is asked to type to demonstrate his/her humanity.
I generated these images using PHP5 and the gd image library which comes bundled with PHP. Two questions: 1) are they easy enough to read? 2) would they be hard enough to OCR?
I’d like to make a PHP-based captcha facility generally available, either as code or as a web service, in hopes that it would help in the fight against blog comment spam. (More about that when it’s ready.)