PEAR Text_CAPTCHA 0.4.0 alpha

$imageOptions = array(
            'font_size' => 24,
            'font_path' => Zend_Registry::get('config')->paths->data,
            'font_file' => 'segoeprb.ttf',
            'text_color' => '#DDFF99',
            'lines_color' => '#CCEEDD',
            'background_color' => '#555555'
        );
$captcha = Text_CAPTCHA::factory('Image');
$captcha->init(180, 60, $phrase, $imageOptions);
$session->phrase = $captcha->getPhrase();
// disable auto-rendering since we're outputting an image
        $this->_helper->viewRenderer->setNoRender();
        header('Content-type: image/png');
        echo $captcha->getCAPTCHAAsPng();