本文目录导读：
我来帮你详细介绍PHP项目中的水印和指纹技术实现。
图片水印处理
文字水印
<?php
class ImageWatermark {
/**
* 添加文字水印
* @param string $source 原图路径
* @param string $text 水印文字
* @param array $options 配置选项
* @return string 处理后的图片路径
*/
public function addTextWatermark($source, $text, $options = []) {
$defaults = [
'output' => null,
'font' => './fonts/arial.ttf',
'fontSize' => 20,
'angle' => 0,
'x' => 10,
'y' => 10,
'color' => [255, 255, 255],
'opacity' => 50
];
$options = array_merge($defaults, $options);
// 创建图片资源
$imageInfo = getimagesize($source);
$mime = $imageInfo['mime'];
switch($mime) {
case 'image/jpeg':
$im = imagecreatefromjpeg($source);
break;
case 'image/png':
$im = imagecreatefrompng($source);
break;
case 'image/gif':
$im = imagecreatefromgif($source);
break;
default:
throw new Exception('不支持的图片格式');
}
// 创建颜色
$color = imagecolorallocatealpha(
$im,
$options['color'][0],
$options['color'][1],
$options['color'][2],
$options['opacity']
);
// 添加水印文字
imagettftext(
$im,
$options['fontSize'],
$options['angle'],
$options['x'],
$options['y'],
$color,
$options['font'],
$text
);
// 输出或保存
$output = $options['output'] ?: $source;
$this->saveImage($im, $output, $mime);
imagedestroy($im);
return $output;
}
}
图片水印（Logo）
<?php
class ImageLogoWatermark {
/**
* 添加图片水印
* @param string $source 原图
* @param string $watermark 水印图片
* @param string $position 位置 (center/top-left/top-right/bottom-left/bottom-right)
*/
public function addImageWatermark($source, $watermark, $position = 'bottom-right') {
// 获取图片信息
$sourceInfo = getimagesize($source);
$watermarkInfo = getimagesize($watermark);
// 创建图片资源
$sourceImg = $this->createImageFromFile($source);
$watermarkImg = $this->createImageFromFile($watermark);
// 计算水印位置
$positions = [
'center' => [
'x' => ($sourceInfo[0] - $watermarkInfo[0]) / 2,
'y' => ($sourceInfo[1] - $watermarkInfo[1]) / 2
],
'top-left' => ['x' => 10, 'y' => 10],
'top-right' => ['x' => $sourceInfo[0] - $watermarkInfo[0] - 10, 'y' => 10],
'bottom-left' => ['x' => 10, 'y' => $sourceInfo[1] - $watermarkInfo[1] - 10],
'bottom-right' => [
'x' => $sourceInfo[0] - $watermarkInfo[0] - 10,
'y' => $sourceInfo[1] - $watermarkInfo[1] - 10
]
];
$pos = $positions[$position] ?? $positions['bottom-right'];
// 合并图片
imagecopy(
$sourceImg,
$watermarkImg,
$pos['x'],
$pos['y'],
0,
0,
$watermarkInfo[0],
$watermarkInfo[1]
);
// 保存
$this->saveImage($sourceImg, $source, $sourceInfo['mime']);
imagedestroy($sourceImg);
imagedestroy($watermarkImg);
}
private function createImageFromFile($file) {
$info = getimagesize($file);
switch($info['mime']) {
case 'image/jpeg':
return imagecreatefromjpeg($file);
case 'image/png':
return imagecreatefrompng($file);
case 'image/gif':
return imagecreatefromgif($file);
}
}
}
数字指纹技术
文件指纹（哈希）
<?php
class FileFingerprint {
/**
* 计算文件指纹
*/
public static function generateFileFingerprint($filePath) {
if (!file_exists($filePath)) {
throw new Exception('文件不存在');
}
return [
'md5' => md5_file($filePath),
'sha1' => sha1_file($filePath),
'sha256' => hash_file('sha256', $filePath),
'crc32' => hash_file('crc32', $filePath),
'size' => filesize($filePath),
'created_at' => filectime($filePath),
'modified_at' => filemtime($filePath)
];
}
/**
* 验证文件完整性
*/
public static function verifyFileIntegrity($filePath, $expectedHash, $algorithm = 'md5') {
$actualHash = hash_file($algorithm, $filePath);
return hash_equals($expectedHash, $actualHash);
}
}
图片感知哈希（pHash）
<?php
class ImagePerceptualHash {
/**
* 计算图片感知哈希
*/
public static function calculatePerceptualHash($imagePath) {
// 缩小图片到8x8
$img = imagecreatefromstring(file_get_contents($imagePath));
$img = imagescale($img, 8, 8);
// 转换为灰度
imagefilter($img, IMG_FILTER_GRAYSCALE);
// 计算平均颜色值
$pixels = [];
$total = 0;
for ($y = 0; $y < 8; $y++) {
for ($x = 0; $x < 8; $x++) {
$color = imagecolorat($img, $x, $y);
$gray = ($color >> 16) & 0xFF;
$pixels[] = $gray;
$total += $gray;
}
}
$average = $total / 64;
// 生成哈希
$hash = '';
foreach ($pixels as $pixel) {
$hash .= ($pixel >= $average) ? '1' : '0';
}
imagedestroy($img);
return $hash;
}
/**
* 比较两个感知哈希的相似度
*/
public static function compareHashes($hash1, $hash2) {
$distance = 0;
$len = strlen($hash1);
for ($i = 0; $i < $len; $i++) {
if ($hash1[$i] !== $hash2[$i]) {
$distance++;
}
}
return [
'distance' => $distance,
'similarity' => (1 - $distance / $len) * 100
];
}
}
高级水印系统
批量水印处理
<?php
class BatchWatermarkProcessor {
private $watermark;
private $config;
public function __construct($watermark, $config = []) {
$this->watermark = $watermark;
$this->config = $config;
}
/**
* 批量处理文件夹中的图片
*/
public function processDirectory($inputDir, $outputDir, $pattern = '*.*') {
if (!is_dir($outputDir)) {
mkdir($outputDir, 0755, true);
}
$files = glob($inputDir . '/' . $pattern);
$processed = [];
foreach ($files as $file) {
if (is_file($file) && $this->isImage($file)) {
$outputPath = $outputDir . '/' . basename($file);
try {
$result = $this->processSingleImage($file, $outputPath);
$processed[] = [
'source' => $file,
'output' => $outputPath,
'status' => 'success',
'size_before' => filesize($file),
'size_after' => filesize($outputPath)
];
} catch (Exception $e) {
$processed[] = [
'source' => $file,
'status' => 'error',
'message' => $e->getMessage()
];
}
}
}
return $processed;
}
private function isImage($file) {
$extensions = ['jpg', 'jpeg', 'png', 'gif', 'webp'];
$ext = strtolower(pathinfo($file, PATHINFO_EXTENSION));
return in_array($ext, $extensions);
}
private function processSingleImage($source, $output) {
// 实现具体的水印处理逻辑
// 可以复用之前的文字水印或图片水印类
}
}
动态水印生成
<?php
class DynamicWatermarkGenerator {
/**
* 生成基于用户信息的动态水印
*/
public static function generateUserWatermark($userId, $username, $timestamp) {
$watermarkData = [
'user_id' => $userId,
'username' => $username,
'timestamp' => $timestamp,
'ip' => $_SERVER['REMOTE_ADDR'] ?? 'unknown',
'hash' => self::generateSignature($userId, $username, $timestamp)
];
// 生成水印文本
$text = sprintf(
"用户: %s\n时间: %s\nIP: %s",
$watermarkData['username'],
date('Y-m-d H:i:s', $watermarkData['timestamp']),
$watermarkData['ip']
);
return $text;
}
/**
* 生成验证签名
*/
private static function generateSignature($userId, $username, $timestamp) {
$secretKey = 'your-secret-key';
$data = $userId . $username . $timestamp . $secretKey;
return hash_hmac('sha256', $data, $secretKey);
}
}
水印检测与验证
水印检测
<?php
class WatermarkDetector {
/**
* 检测图片是否包含水印
*/
public static function detectWatermark($imagePath, $referenceWatermark) {
// 提取图片特征
$features = self::extractFeatures($imagePath);
// 计算与参考水印的相似度
$similarity = self::calculateSimilarity($features, $referenceWatermark);
return [
'has_watermark' => $similarity > 0.8,
'similarity' => $similarity,
'position' => self::detectPosition($features)
];
}
private static function extractFeatures($imagePath) {
// 实现特征提取逻辑
// 例如边缘检测、颜色直方图等
}
private static function calculateSimilarity($features1, $features2) {
// 计算特征相似度
}
private static function detectPosition($features) {
// 检测水印位置
}
}
水印去除检测
<?php
class WatermarkTamperDetector {
/**
* 检测水印是否被篡改
*/
public static function checkTampering($originalFile, $suspiciousFile) {
// 比较文件指纹
$originalHash = FileFingerprint::generateFileFingerprint($originalFile);
$suspiciousHash = FileFingerprint::generateFileFingerprint($suspiciousFile);
// 感知哈希比较
$phash1 = ImagePerceptualHash::calculatePerceptualHash($originalFile);
$phash2 = ImagePerceptualHash::calculatePerceptualHash($suspiciousFile);
$phashComparison = ImagePerceptualHash::compareHashes($phash1, $phash2);
return [
'tampered' => $phashComparison['similarity'] < 95,
'hash_matched' => $originalHash['md5'] === $suspiciousHash['md5'],
'phash_similarity' => $phashComparison['similarity'],
'details' => [
'original' => $originalHash,
'suspicious' => $suspiciousHash
]
];
}
}
使用示例
<?php
// 1. 添加文字水印
$watermark = new ImageWatermark();
$result = $watermark->addTextWatermark(
'image.jpg',
'© 2024 Your Company',
['fontSize' => 30, 'opacity' => 30]
);
// 2. 计算文件指纹
$fingerprint = FileFingerprint::generateFileFingerprint('document.pdf');
// 3. 图片相似度检测
$phash1 = ImagePerceptualHash::calculatePerceptualHash('image1.jpg');
$phash2 = ImagePerceptualHash::calculatePerceptualHash('image2.jpg');
$comparison = ImagePerceptualHash::compareHashes($phash1, $phash2);
echo "相似度: " . $comparison['similarity'] . "%";
// 4. 批量处理
$batchProcessor = new BatchWatermarkProcessor('watermark.png');
$results = $batchProcessor->processDirectory('images/', 'watermarked/');
这些实现提供了完整的水印和指纹功能,可以根据项目需求进行定制和扩展。
