PHP QR Code barcode and QR code generation class library

//生成带logo的二维码图片

 include 'phpqrcode.php';
 $value = 'http://www.cnblogs.com/txw1958/'; //QR code content
 $errorCorrectionLevel = 'L';/ /Error tolerance level
 $matrixPointSize = 6; //Generate image size
 //Generate QR code image
 QRcode::png($value, 'qrcode.png', $errorCorrectionLevel, $matrixPointSize, 2);
 $logo = 'logo.png';//Prepared logo image
 $QR = 'qrcode.png';//Generated original QR code image

 if ($logo !== FALSE) {
 $QR = imagecreatefromstring (file_get_contents($QR));
 $logo = imagecreatefromstring(file_get_contents($logo));
 $QR_width = imagesx($QR);//QR code image width
 $QR_height = imagesy($QR);// QR code image height
 $logo_width = imagesx($logo);//logo image width
 $logo_height = imagesy($logo);//logo image height
 $logo_qr_width = $QR_width / 5;
 $scale = $logo_width /$logo_qr_width;
 $logo_qr_height = $logo_height/$scale;
 $from_width = ($QR_width - $logo_qr_width) / 2;
 //Recombine the image and resize
 imagecopyresampled($QR, $logo, $from_width, $ from_width, 0, 0, $logo_qr_width,
 $logo_qr_height, $logo_width, $logo_height);
 }
 //Output image
 imagepng($QR, 'helloweixin.png');
 echo '';

Class library, PHP