QRcode provides to Kohana an easy way to generate ISO/IEC 18004:2006 quick response codes compatible with almost mobile 2-D QRcode readers.
// Force content type
$this->response->headers('Content-Type','image/png');
// Show QRcode
$this->response->body(QRCode::instance()->png('http://kohanaframework.org/'));
// Save as qrcode.png
QRCode::instance()->png('http://kohanaframework.org/', 'qrcode.png');