php captcha styles

[atomicrabbit]

I know captchas have been discussed a lot on this forum, and I know how to use them, but I'm wondering how I can get specific style. I see very nice styles around and wonder how they are done.

 

I'm looking for something more similar to that which Google is using on their own sites, although something with a random background (i've seen it before):

 

 

And maybe something similar to reCaptcha:

 

 

Except without using their database. The problem with reCaptcha is that it has to use their database for the captcha's, it is not generated within the server you insert the captcha on. It calls back to the recaptcha.net server to get an image. Basically I'm just looking for the style of font (with the distortion) and the slashed line that reCaptcha has. not sure how to do that.

 

Basically i'm just wondering how all the different styles are made, so I can implement them myself.