Method render

/**
 * Render the document.
 *
 * @param   boolean  $cache   If true, cache the output
 * @param   array    $params  Associative array of attributes
 *
 * @return  string  The rendered data
 *
 * @since   3.0.0
 */
public function render($cache = false, $params = array())
{
    // Get the image type
    $type = Factory::getApplication()->input->get('type', 'png');
    switch ($type) {
        case 'jpg':
        case 'jpeg':
            $this->_mime = 'image/jpeg';
            break;
        case 'gif':
            $this->_mime = 'image/gif';
            break;
        case 'png':
        default:
            $this->_mime = 'image/png';
            break;
    }
    $this->_charset = null;
    parent::render($cache, $params);
    return $this->getBuffer();
}