CAPTCHA images/algorithms

[helraizer1]

Hi all, I'm not sure whether or not this is PHP or not, though I'd assume so with the Dynamic Images and OOP.

I am currently implimenting user accounts on my website and to stop bots I was thinking of including a CAPTCHA image. Most people use generated images from the EZ-Gimpy program, but not all.

I was wondering how, using PHP with gd2 library, would/could I create a captcha like image with distorted background?

Or would I be better off using the pre-generated ones?

Thanks, Sam.

[Motoma]

Hi all, I'm not sure whether or not this is PHP or not, though I'd assume so with the Dynamic Images and OOP.

I am currently implimenting user accounts on my website and to stop bots I was thinking of including a CAPTCHA image. Most people use generated images from the EZ-Gimpy program, but not all.

I was wondering how, using PHP with gd2 library, would/could I create a captcha like image with distorted background?

Or would I be better off using the pre-generated ones?

Thanks, Sam.

Pre-generated ones have the benefit of typically being a cut and paste solution.
Making your own, though, has benefits; you can modify them to suit your particular specifications on readability and difficulty.
If I were to go about doing this, I would create a large smeared image in Photoshop and save it. The CAPTCHA then randomly chooses two points in the image, crops to those two points, stretches or shrinks the image to fit in the size of the image you wish to produce (distortion), and then render multicolored text on top of it.