|This class can be used to perform CAPTCHA validation of human users.
It generates an image with a random text rendered in a fuzzy way to make it difficult to guess by robots.
The configuration details are read from an file in the ini format.
Several types of options can be configured like the text fonts, letters, colors and the noise level of the generated image.
The verification image is generated in the JPEG format.
The class stores an MD5 hash of the verification text in a session variable.