Core_Controller_Captcha::action_default

public function action_default($type='')
{
    $width = 80;
    $height = 30;
    if ($type && preg_match('#^([0-9]+)x([0-9]+)\.png$#i', $type,$m))
    {
        if ($m[1]>0)$width = $m[1];
        if ($m[1]>0)$height = $m[2];
    }
    Captcha::render(array('width'=>$width,'height'=>$height));
}