PHP calls google interface to generate QR code example

For example, call the Google interface to implement the QR code.

?php
$data = isset($_GET['t']) ? $_GET['t'] : 'http://www.XXX.com';
$size = isset($_GET['size']) ? $_GET['size'] : '150x150';
$logo = isset($_GET['logo']) ? $_GET['logo'] : "./ image/logo.jpg";
$chl = urlencode($logo);
$png = "http://chart.googleapis.com/chart?chs=$size&cht=qr&chl=$chl&chld=L|1&choe= UTF-8";
$QR = imagecreatefrompng($png);//The QR image outside
//The following is the main code for QR code generation
if ($logo !== FALSE) {
$ logo = imagecreatefromstring(file_get_contents($logo));
$QR_width = imagesx($QR);
$QR_height = imagesy($QR);
$logo_width = imagesx($logo);
$logo_height = imagesy ($logo);
$logo_qr_width = $QR_width/5;
$scale = $logo_width/$logo_qr_width;
$logo_qr_height = $logo_height/$scale;
$from_width = ($QR_width-$logo_ qr_width)/ 2;
imagecopyresampled($QR, $logo, $from_width, $from_width, 0, 0, $logo_qr_width, $logo_qr_height, $logo_width, $logo_height);
}
header('Content-type: image/png ');
imagepng($QR);
//Destroy the QR code image
imagedestroy($QR);
?>