EllisLab/CodeIgniter — pull request #2091 by vov1 (2012-12-21 18:43:36+00:00)
Title: CAPTCHA Helper Extension

Added function create_captcha_stream()
Where:
Removed write files to the hard drive and added implement stream output images directly to the browser.
Character placement fix.
Add the ability to specify the length of random string.
Add the ability to create an image with border and without border.
Add generation of random color scheme for the image.