php之使用gd库给图片添加文字以及图片:
这个功能其实很简单，设计出图片模板，然后再指定的位置替换上 指定的内容即可，代码如下:

<?php

namespace App\Service;

use Symfony\Component\Validator\Constraints\Date;

class CertificationService
{
    public static string $signatureName = 'John Doe';

    public static string $prefix = 'certification';

    /**
     * @throws \Exception
     */
    public static function generateCertification($name, $course, $createdAt): string
    {
        $imgPath       = './statics/img/certificationTemplate.png';
        $fontPathB     = './statics/img/suisse/SuisseIntl-SemiBold.otf'; // 600 字体文件
        $fontPathM     = './statics/img/suisse/SuisseIntl-Medium.otf'; // 500 字体文件
        $signaturePath = './statics/img/signature.png';

        $img = imagecreatefrompng($imgPath);

        $font_size = 18;
        $color     = imagecolorallocate($img, 0, 0, 0);

        if ($name) {
            $x = 1080;
            $y = 301 + 20; // 404.6 - (10 + ( 28 - 20 ) / 2)

            //将$name 方法模板的水平中间位置，这个要先通过 imagettfbbox 将文字格式化为文字盒子，再计算出这个文字盒子的宽高，用 (总宽度 - 盒子宽度)/2，得到中间位置
            $nameBox = imagettfbbox($font_size, 0, $fontPathB, $name);

            self::imageToText($img, $font_size, ceil(($x - $nameBox[2]) / 2), $y, $color, $fontPathB, $name);
        }

        $x = 581;
        $y = 344 + 14 + 8; // 489.6 - (10 + (28 - 20) / 2)
        self::imageToText($img, $font_size, $x, $y, $color, $fontPathB, $course);

        //sig 将signature 图片添加到模板的指定位置
        $overlayImage = imagecreatefrompng($signaturePath);
        list($overlayWidth, $overlayHeight) = getimagesize($signaturePath);

        imagecopy($img, $overlayImage, 656, 456, 0, 0, $overlayWidth, $overlayHeight);

        if ($name) {
            $number = '';
            array_map(function ($item) use (&$number) {
                $number .= substr($item, 0, 1);
            }, explode(" ", ucwords($course)));
            $number  .= ' ' . random_int(10000, 99999);
            $x       = 357;
            $yNumber = 503 + 24; // 554.6 + 20 + (28 - 20) / 2
            self::imageToText($img, 16, $x, $yNumber, $color, $fontPathM, $number);

            $time  = \date('Y.m.d', time());
            $yTime = 537 + 24;
            self::imageToText($img, 16, $x, $yTime, $color, $fontPathM, $time);
        }

        $date     = (new \DateTime())->format('Y-m-d');
        $ext      = substr($imgPath, strripos($imgPath, '.'));
        $destDir  = 'upload' . '/' . self::$prefix . '/' . $date . '/';
        $filename = md5(microtime()) . $ext;

        if (!is_dir($destDir)) {
            @mkdir($destDir, 0777, true);
        }

        imagepng($img, './' . $destDir . $filename);

        imagedestroy($img);

        return $destDir . $filename;
    }

    public static function imageToText($img, $font_size, $x, $y, $color, $fontPath, $text): void
    {
        imagettftext($img, $font_size, 0, $x, $y, $color, $fontPath, $text);
    }
}