在PHP中为图像添加水印

基本上，我有 2 个 php 脚本.php脚本中的1个是显示，另外1个是水印功能.

Basically, I have 2 php script. 1 of the php scripts is to display and the other 1 is the watermark function.

我使用这个 PHP 来显示带水印的图像:

I use this PHP to display the image with watermark:

<img src="watermark1.php?image=photo.jpg>

这是我的 watermark1.php:

This is my watermark1.php:

<?php
// this tells the browser to render jpg image
header('content-type: image/jpeg'); 

// getting the image name from GET variable
$image = $_GET['image']; 

// creating png image of watermark
$watermark = imagecreatefrompng('watermark.png');   

// getting dimensions of watermark image
$watermark_width = imagesx($watermark);
$watermark_height = imagesy($watermark);  

// creating jpg from original image
$image_path =  $image;
$image = imagecreatefromjpeg($image_path);
//something went wrong
if ($image === false) {
    return false;
}
// getting the dimensions of original image
$size = getimagesize($image_path);
// placing the watermark 5px from bottom and right
$dest_x = $size[0] - $watermark_width - 5;
$dest_y = $size[1] - $watermark_height - 5;
// blending the images together
imagealphablending($image, true);
imagealphablending($watermark, true);
// creating the new image
imagecopy($image, $watermark, $dest_x, $dest_y, 0, 0, $watermark_width, $watermark_height);
imagejpeg($image);
// destroying and freeing memory
imagedestroy($image);
imagedestroy($watermark);
?>

但是，无法显示带水印的图像.我听说过 GDLibrary 和 ImageMagicK，但我不知道这两个是什么.有没有办法只通过添加php代码来添加水印，或者必须导入GDLibrary/ImageMagicK.

However, the watermarked image could not be displayed. I heard about GDLibrary and ImageMagicK but i have no idea what are these 2 about. Is there a way to add watermark just by adding php codes or is it a must to import the GDLibrary/ImageMagicK.

感谢您抽出宝贵时间.