php简单图片与文字合成

public function createOnline($name)
{
    //照片
    $path_2 = '8d5996d672.jpg';

    //创建图片对象
    $image_1 = imagecreatefromstring(file_get_contents($path_2));

    //文件名
    $filename = "temp";

    //设置文字颜色
    $black = imagecolorallocate($image_1, 0, 0, 0);

    //写的文字用到的字体
    $font = realpath('consola.ttf');

    //在图片里插入文字$black
    imagettftext($image_1, 12, 0, 10, 192, $black, $font, $name);

    //这是合成后的图片保存的路径
    $upload_dir = "upload";

    imagepng($image_1, $upload_dir . $filename . '.png');

    $finalurl = 'uploads/certsimg/' . $filename . '.png';

    return $finalurl;

}