php 实现：给图片加文字水印，图片水印，压缩图片

演示环境：
1、windows10
2、phpstudy
3、php7.4

一、案例演示：

二、素材准备

1、准备一张原始图片
2、准备一张水印图片（透明底图的最好）
3、字体库（windows系统自带的字体库，路径在：C:\Windows\Fonts）
4、开启GD库

三、图片添加水印

1、文字水印封装类 FontWatermark.class.php

<?phpclass FontWatermark
{private $sourceImagePath;private $fontPath;private $fontSize;private $watermarkText;private $outputImagePath;public function __construct($sourceImagePath, $fontPath, $fontSize, $watermarkText, $outputImagePath){$this->sourceImagePath = $sourceImagePath;$this->fontPath = realpath($fontPath);  // 获取字体文件的绝对路径$this->fontSize = $fontSize;$this->watermarkText = $watermarkText;$this->outputImagePath = $outputImagePath;}public function addFontWatermark(){// 加载源图片$sourceImage = imagecreatefromjpeg($this->sourceImagePath);if (!$sourceImage) {die('无法加载源图片');}// 获取源图片的宽高$sourceWidth = imagesx($sourceImage);$sourceHeight = imagesy($sourceImage);// 确保字体文件存在if (!file_exists($this->fontPath)) {die('字体文件不存在: ' . $this->fontPath);}// 设置文字颜色 (白色)$white = imagecolorallocate($sourceImage, 255, 255, 255);// 设置文字阴影颜色 (黑色)$black = imagecolorallocate($sourceImage, 0, 0, 0);// 计算文字水印的边界框$textBox = imagettfbbox($this->fontSize, 0, $this->fontPath, $this->watermarkText);if ($textBox === false) {die('无法计算文字边界框');}$textWidth = $textBox[2] - $textBox[0];$textHeight = $textBox[1] - $textBox[7];// 设置文字水印的位置 (左上角)$destX = 10;$destY = $textHeight + 10;// 绘制阴影文字if (imagettftext($sourceImage, $this->fontSize, 0, $destX + 2, $destY + 2, $black, $this->fontPath, $this->watermarkText) === false) {die('无法绘制阴影文字');}// 绘制水印文字if (imagettftext($sourceImage, $this->fontSize, 0, $destX, $destY, $white, $this->fontPath, $this->watermarkText) === false) {die('无法绘制水印文字');}// 保存加水印后的图片if (!imagejpeg($sourceImage, $this->outputImagePath)) {die('无法保存加水印后的图片');}// 释放内存imagedestroy($sourceImage);echo "图片水印已添加并保存到: " . $this->outputImagePath;echo "<br>";echo "<img src='" . $this->outputImagePath . "' alt='文字水印' width='400px;' height='300px;'>";}
}
?>

2、调用文字水印类

<?php
require "FontWatermark.class.php";
// 使用示例
$watermark = new FontWatermark('1111.jpg',                // 源图片路径'msyh.ttc', // 字体路径80,                        // 字体大小'测试水印',                 // 水印文字'font_watermark.jpg' // 输出图片路径
);$watermark->addFontWatermark();?>

四、图片添加图片水印

1、图片水印封装类 WatermarkImage.class.php

<?php
class WatermarkImage
{private $sourceImagePath;private $watermarkImagePath;private $outputImagePath;private $sourceImage;private $watermarkImage;public function __construct($sourceImagePath, $watermarkImagePath, $outputImagePath){$this->sourceImagePath = $sourceImagePath;$this->watermarkImagePath = $watermarkImagePath;$this->outputImagePath = $outputImagePath;}private function loadImages(){// 加载源图片$this->sourceImage = @imagecreatefromjpeg($this->sourceImagePath);if (!$this->sourceImage) {die('无法加载源图片: ' . $this->sourceImagePath);}// 加载水印图片$this->watermarkImage = @imagecreatefrompng($this->watermarkImagePath);if (!$this->watermarkImage) {imagedestroy($this->sourceImage);die('无法加载水印图片: ' . $this->watermarkImagePath);}}private function addWatermark(){// 获取源图片和水印图片的宽高$sourceWidth = imagesx($this->sourceImage);$sourceHeight = imagesy($this->sourceImage);$watermarkWidth = imagesx($this->watermarkImage);$watermarkHeight = imagesy($this->watermarkImage);// 计算水印位置（右下角）$destX = $sourceWidth - $watermarkWidth - 10; // 右边距10像素$destY = $sourceHeight - $watermarkHeight - 10; // 底边距10像素// 将水印图片合并到源图片上imagecopy($this->sourceImage, $this->watermarkImage, $destX, $destY, 0, 0, $watermarkWidth, $watermarkHeight);}private function saveImage(){// 保存加水印后的图片if (!imagejpeg($this->sourceImage, $this->outputImagePath)) {imagedestroy($this->sourceImage);imagedestroy($this->watermarkImage);die('无法保存加水印后的图片: ' . $this->outputImagePath);}}private function cleanup(){// 释放内存imagedestroy($this->sourceImage);imagedestroy($this->watermarkImage);}public function applyWatermark(){$this->loadImages();$this->addWatermark();$this->saveImage();$this->cleanup();echo "图片水印已添加并保存到: " . $this->outputImagePath;echo "<br>";echo "<img src='" . $this->outputImagePath . "' alt='图片水印' width='400px;' height='300px;'>";}
}?>

2、调用图片水印类

<?php
require "WatermarkImage.class.php";
// 使用示例
$sourceImagePath = '1111.jpg';
$watermarkImagePath = 'shuiyin.png';
$outputImagePath = 'image_watermark.jpg';$watermarker = new WatermarkImage($sourceImagePath, $watermarkImagePath, $outputImagePath);
$watermarker->applyWatermark();?>

五、压缩图片

1、缩略图封装类 ImageResizer

<?phpclass ImageResizer
{private $sourceImage;private $sourceWidth;private $sourceHeight;public function __construct($sourceImagePath){$this->loadImage($sourceImagePath);}private function loadImage($path){if (!file_exists($path)) {throw new Exception("File does not exist: $path");}$this->sourceImage = imagecreatefromjpeg($path);if (!$this->sourceImage) {throw new Exception("Failed to load image: $path");}$this->sourceWidth = imagesx($this->sourceImage);$this->sourceHeight = imagesy($this->sourceImage);}public function resize($width, $height, $outputPath){$thumb = imagecreatetruecolor($width, $height);imagecopyresampled($thumb,$this->sourceImage,0,0,0,0,$width,$height,$this->sourceWidth,$this->sourceHeight);if (!imagejpeg($thumb, $outputPath)) {throw new Exception("Failed to save thumbnail to: $outputPath");}imagedestroy($thumb);}public function __destruct(){imagedestroy($this->sourceImage);}
}?>

2、调用缩略图类

<?php
require "Resizer.class.php";// 使用示例
try {$sourceImagePath = 'E:\test\Resizer\222.jpg';// $outputImagePath = 'E:\test\Resizer\222_resier.jpg';$outputImagePath = '222_resier.jpg';$width = 200;$height = 200;$resizer = new ImageResizer($sourceImagePath);$resizer->resize($width, $height, $outputImagePath);echo "缩略图创建在网站目录下，图片名称: $outputImagePath";echo "<br>";echo "<img src='$outputImagePath' alt='缩略图'>";
} catch (Exception $e) {echo "错误: " . $e->getMessage();
}
?>

说明：更多复杂的水印功能可以基于此脚本扩展