public static function svg($frame, $filename = false, $pixelPerPoint = 4, $outerFrame = 4, $saveandprint = FALSE, $back_color, $fore_color)
 {
     $vect = self::vectSVG($frame, $pixelPerPoint, $outerFrame, $back_color, $fore_color);
     if ($filename === false) {
         header("Content-Type: image/svg+xml");
         //header('Content-Disposition: attachment, filename="qrcode.svg"');
         echo $vect;
     } else {
         if ($saveandprint === TRUE) {
             QRtools::save($vect, $filename);
             header("Content-Type: image/svg+xml");
             //header('Content-Disposition: filename="'.$filename.'"');
             echo $vect;
         } else {
             QRtools::save($vect, $filename);
         }
     }
 }