internal package Foswiki::Plugins::CaptchaPlugin::Captcha  class to manage the captcha
ClassMethod new() → $captcha constructor for a captcha object
ObjectMethod randomColor() → [$r, g, b] returns a random rbg color
ObjectMethod invertColor($rgb) → [$r, $g, $b] inverts the givene color
ObjectMethod writeDebug($message) prints debug $message to STDERR
ObjectMethod toHash() → $hash returns a hash representation of this captcha
ObjectMethod toHtml() → $html returns a html representation of this captcha
ObjectMethod init($dontCreate) inits this captcha
ObjectMethod isValid($response, $forceDelete) → $boolean returns true if the given response is valid with respect to this captcha