CaptchaImage Control

The CaptchaImage extends the DynamicImage so many aspects are the same, reason for you first to read the DynamicImage documentation about Configuration and Performace.

Unlike DynamicImage, the CaptchaImage generates the image following well a defined pattern; the text is a configurable random choice.

In this model, the text generation is handled by the CaptchaImage and is applied by the CaptchaImageProvider which takes it from the image src query string; the text value from the src is crypted using DES and a password key hardcoded into CaptchaImageProvider.