$bigImgPath = 'backgroud.png';

    $img = imagecreatefromstring(file_get_contents($bigImgPath));

    $font = 'msyhl.ttc';//字体

    $black = imagecolorallocate($img, 0, 0, 0);//字体颜色 RGB

    $fontSize = 20;   //字体大小

    $circleSize = 60; //旋转角度

    $left = 50;      //左边距

    $top = 150;       //顶边距

    imagefttext($img, $fontSize, $circleSize, $left, $top, $black, $font, 'Rhythmk| 坤');

    list($bgWidth, $bgHight, $bgType) = getimagesize($bigImgPath);

    switch ($bgType) {

        case 1: //gif

            header('Content-Type:image/gif');

            imagegif($img);

            break;

        case 2: //jpg

            header('Content-Type:image/jpg');

            imagejpeg($img);

            break;

        case 3: //jpg

            header('Content-Type:image/png');

            imagepng($img);

            break;

        default:

            break;

    }

    imagedestroy($img);

        $bigImgPath = 'backgroud.png';

        $qCodePath = 'qcode.png';

        $bigImg = imagecreatefromstring(file_get_contents($bigImgPath));

        $qCodeImg = imagecreatefromstring(file_get_contents($qCodePath));

        list($qCodeWidth, $qCodeHight, $qCodeType) = getimagesize($qCodePath);

        // imagecopymerge使用注解

        imagecopymerge($bigImg, $qCodeImg, 200, 300, 0, 0, $qCodeWidth, $qCodeHight, 100);

        list($bigWidth, $bigHight, $bigType) = getimagesize($bigImgPath);

        switch ($bigType) {

            case 1: //gif

                header('Content-Type:image/gif');

                imagegif($bigImg);

                break;

            case 2: //jpg

                header('Content-Type:image/jpg');

                imagejpeg($bigImg);

                break;

            case 3: //jpg

                header('Content-Type:image/png');

                imagepng($bigImg);

                break;

            default:

                # code...

                break;

        }

        imagedestroy($bigImg);

        imagedestroy($qcodeImg);