PHP给图片加上图片水印和文字水印实例

下面给大家分享一下PHP给图片加上图片水印和文字水印实例，这也是网站经常用到的功能，把代码加上去，调用就很简单了。

核心代码：

 function imageWaterMark($groundImage, $waterPos = 0, $waterImage = "", $waterText = "", $textFont = 5, $textColor = "#FF0000") { 
 
     $isWaterImage = FALSE; 
 
     $formatMsg = "暂不支持该文件格式，请用图片处理软件将图片转换为GIF、JPG、PNG格式。"; 
 
     //读取水印文件 
 
     if (!empty($waterImage) && file_exists($waterImage)) { 
 
         $isWaterImage = TRUE; 
 
         $water_info = getimagesize($waterImage); 
 
         $water_w = $water_info[0]; //取得水印图片的宽 
 
         $water_h = $water_info[1]; //取得水印图片的高  
 
         switch ($water_info[2]) {//取得水印图片的格式
             case 1:$water_im = imagecreatefromgif($waterImage);
                 break; 
 
             case 2:$water_im = imagecreatefromjpeg($waterImage);
                 break; 
 
             case 3:$water_im = imagecreatefrompng($waterImage);
                 break; 
 
             default:die($formatMsg);
         }
     } 
 
     //读取背景图片 
 
     if (!empty($groundImage) && file_exists($groundImage)) { 
 
         $ground_info = getimagesize($groundImage); 
 
         $ground_w = $ground_info[0]; //取得背景图片的宽 
 
         $ground_h = $ground_info[1]; //取得背景图片的高 
 
         switch ($ground_info[2]) {//取得背景图片的格式
             case 1:$ground_im = imagecreatefromgif($groundImage);
                 break; 
 
             case 2:$ground_im = imagecreatefromjpeg($groundImage);
                 break; 
 
             case 3:$ground_im = imagecreatefrompng($groundImage);
                 break; 
 
             default:die($formatMsg);
         }
     } else { 
 
         die("需要加水印的图片不存在！");
     } 
 
     //水印位置 
 
     if ($isWaterImage) {//图片水印
         $w = $water_w; 
 
         $h = $water_h; 
 
         $label = "图片的";
     } else {//文字水印
         $temp = imagettfbbox(ceil($textFont * 5), 0, "./cour.ttf", $waterText); //取得使用 TrueType 字体的文本的范围 
 
         $w = $temp[2] - $temp[6]; 
 
         $h = $temp[3] - $temp[7]; 
 
         unset($temp); 
 
         $label = "文字区域";
     } 
 
     if (($ground_w < $w) || ($ground_h < $h)) { 
 
         echo "需要加水印的图片的长度或宽度比水印" . $label . "还小，无法生成水印！"; 
 
         return;
     } 
 
     switch ($waterPos) { 
 
         case 0://随机 
 
             $posX = rand(0, ($ground_w - $w)); 
 
             $posY = rand(0, ($ground_h - $h)); 
 
             break; 
 
         case 1://1为顶端居左 
 
             $posX = 0; 
 
             $posY = 0; 
 
             break; 
 
         case 2://2为顶端居中 
 
             $posX = ($ground_w - $w) / 2; 
 
             $posY = 0; 
 
             break; 
 
         case 3://3为顶端居右 
 
             $posX = $ground_w - $w; 
 
             $posY = 0; 
 
             break; 
 
         case 4://4为中部居左 
 
             $posX = 0; 
 
             $posY = ($ground_h - $h) / 2; 
 
             break; 
 
         case 5://5为中部居中 
 
             $posX = ($ground_w - $w) / 2; 
 
             $posY = ($ground_h - $h) / 2; 
 
             break; 
 
         case 6://6为中部居右 
 
             $posX = $ground_w - $w; 
 
             $posY = ($ground_h - $h) / 2; 
 
             break; 
 
         case 7://7为底端居左 
 
             $posX = 0; 
 
             $posY = $ground_h - $h; 
 
             break; 
 
         case 8://8为底端居中 
 
             $posX = ($ground_w - $w) / 2; 
 
             $posY = $ground_h - $h; 
 
             break; 
 
         case 9://9为底端居右 
 
             $posX = $ground_w - $w - 10;   // -10 是距离右侧10px 可以自己调节 
 
             $posY = $ground_h - $h - 10;   // -10 是距离底部10px 可以自己调节 
 
             break; 
 
         default://随机 
 
             $posX = rand(0, ($ground_w - $w)); 
 
             $posY = rand(0, ($ground_h - $h)); 
 
             break;
     } 
 
     //设定图像的混色模式 
 
     imagealphablending($ground_im, true); 
 
     if ($isWaterImage) {//图片水印
         imagecopy($ground_im, $water_im, $posX, $posY, 0, 0, $water_w, $water_h); //拷贝水印到目标文件
     } else {//文字水印
         if (!emptyempty($textColor) && (strlen($textColor) == 7)) { 
 
             $R = hexdec(substr($textColor, 1, 2)); 
 
             $G = hexdec(substr($textColor, 3, 2)); 
 
             $B = hexdec(substr($textColor, 5));
         } else { 
 
             die("水印文字颜色格式不正确！");
         } 
 
         imagestring($ground_im, $textFont, $posX, $posY, $waterText, imagecolorallocate($ground_im, $R, $G, $B));
     } 
 
     //生成水印后的图片 
 
     @unlink($groundImage); 
 
     switch ($ground_info[2]) {//取得背景图片的格式
         case 1:imagegif($ground_im, $groundImage);
             break; 
 
         case 2:imagejpeg($ground_im, $groundImage);
             break; 
 
         case 3:imagepng($ground_im, $groundImage);
             break; 
 
         default:die($errorMsg);
     } 
 
     //释放内存 
 
     if (isset($water_info))
         unset($water_info); 
 
     if (isset($water_im))
         imagedestroy($water_im); 
 
     unset($ground_info); 
 
     imagedestroy($ground_im);
 }

文字水印：

waterText('banner.jpg', 9, '','sucaihuo.com'); //背景图片,$waterPos水印位置,水印图片地址

图片水印：

imageWaterMark('404.jpg', 9, 'logo.gif'); //背景图片,$waterPos水印位置,水印图片地址

注意：$waterImage 和 $waterText 最好不要同时使用，选其中之一即可，优先使用 $waterImage。

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文字水印