这个类功能很强大，细节很棒！希望大家喜欢，并积极指点。支持文字水印、图片水印支持水印的位置随机或固定（九宫格）水印透明度设置（图片水印和文字水印都支持）文字 水印的字体、颜色、大小设置图片水印的背景透明

[PHP]代码

<?php  /**   * 加水印类，支持文字图片水印的透明度设置、水印图片背景透明。   * 日期：2011-09-27   * 作者：www.itwhy.org   * 使用：   *      $obj = new WaterMask($imgFileName);         //实例化对象   *      $obj->$waterType = 1;                       //类型：0为文字水印、1为图片水印   *      $obj->$transparent = 45;                    //水印透明度   *      $obj->$waterStr = 'www.itwhy.org';          //水印文字   *      $obj->$fontSize = 16;                       //文字字体大小   *      $obj->$fontColor = array(255,0255);         //水印文字颜色（RGB）   *      $obj->$fontFile = = 'AHGBold.ttf';          //字体文件   *      $obj->output();                             //输出水印图片文件覆盖到输入的图片文件   */  class WaterMask{      public  $waterType          = 1;                //水印类型：0为文字水印、1为图片水印      public  $pos                = 0;                //水印位置      public  $transparent        = 45;               //水印透明度        public  $waterStr           = 'www.itwhy.org';  //水印文字      public  $fontSize           = 16;               //文字字体大小      public  $fontColor          = array(255,0,255); //水印文字颜色（RGB）      public  $fontFile           = 'AHGBold.ttf';    //字体文件        public  $waterImg           = 'logo.png';       //水印图片        private $srcImg             = '';               //需要添加水印的图片      private $im                 = '';               //图片句柄      private $water_im           = '';               //水印图片句柄      private $srcImg_info        = '';               //图片信息      private $waterImg_info      = '';               //水印图片信息      private $str_w              = '';               //水印文字宽度      private $str_h              = '';               //水印文字高度      private $x                  = '';               //水印X坐标      private $y                  = '';               //水印y坐标        function __construct($img) {        //析构函数          $this->srcImg = file_exists($img) ? $img : die('"'.$img.'" 源文件不存在！');      }      private function imginfo() {                //获取需要添加水印的图片的信息，并载入图片。          $this->srcImg_info = getimagesize($this->srcImg);          switch ($this->srcImg_info[2]) {              case 3:                  $this->im = imagecreatefrompng($this->srcImg);                  break 1;              case 2:                  $this->im = imagecreatefromjpeg($this->srcImg);                  break 1;              case 1:                  $this->im = imagecreatefromgif($this->srcImg);                  break 1;              default:                  die('原图片（'.$this->srcImg.'）格式不对，只支持PNG、JPEG、GIF。');          }      }      private function waterimginfo() {           //获取水印图片的信息，并载入图片。          $this->waterImg_info = getimagesize($this->waterImg);          switch ($this->waterImg_info[2]) {              case 3:                  $this->water_im = imagecreatefrompng($this->waterImg);                  break 1;              case 2:                  $this->water_im = imagecreatefromjpeg($this->waterImg);                  break 1;              case 1:                  $this->water_im = imagecreatefromgif($this->waterImg);                  break 1;              default:                  die('水印图片（'.$this->srcImg.'）格式不对，只支持PNG、JPEG、GIF。');          }      }      private function waterpos() {               //水印位置算法          switch ($this->pos) {              case 0:     //随机位置                  $this->x = rand(0,$this->srcImg_info[0]-$this->waterImg_info[0]);                  $this->y = rand(0,$this->srcImg_info[1]-$this->waterImg_info[1]);                  break 1;              case 1:     //上左                  $this->x = 0;                  $this->y = 0;                  break 1;              case 2:     //上中                  $this->x = ($this->srcImg_info[0]-$this->waterImg_info[0])/2;                  $this->y = 0;                  break 1;              case 3:     //上右                  $this->x = $this->srcImg_info[0]-$this->waterImg_info[0];                  $this->y = 0;                  break 1;              case 4:     //中左                  $this->x = 0;                  $this->y = ($this->srcImg_info[1]-$this->waterImg_info[1])/2;                  break 1;              case 5:     //中中                  $this->x = ($this->srcImg_info[0]-$this->waterImg_info[0])/2;                  $this->y = ($this->srcImg_info[1]-$this->waterImg_info[1])/2;                  break 1;              case 6:     //中右                  $this->x = $this->srcImg_info[0]-$this->waterImg_info[0];                  $this->y = ($this->srcImg_info[1]-$this->waterImg_info[1])/2;                  break 1;              case 7:     //下左                  $this->x = 0;                  $this->y = $this->srcImg_info[1]-$this->waterImg_info[1];                  break 1;              case 8:     //下中                  $this->x = ($this->srcImg_info[0]-$this->waterImg_info[0])/2;                  $this->y = $this->srcImg_info[1]-$this->waterImg_info[1];                  break 1;              default:    //下右                  $this->x = $this->srcImg_info[0]-$this->waterImg_info[0];                  $this->y = $this->srcImg_info[1]-$this->waterImg_info[1];                  break 1;          }      }      private function waterimg() {          if ($this->srcImg_info[0] <= $this->waterImg_info[0] || $this->srcImg_info[1] <= $this->waterImg_info[1]){              die('水印比原图大！');          }          $this->waterpos();          $cut = imagecreatetruecolor($this->waterImg_info[0],$this->waterImg_info[1]);          imagecopy($cut,$this->im,0,0,$this->x,$this->y,$this->waterImg_info[0],$this->waterImg_info[1]);          $pct = $this->transparent;          imagecopy($cut,$this->water_im,0,0,0,0,$this->waterImg_info[0],$this->waterImg_info[1]);          imagecopymerge($this->im,$cut,$this->x,$this->y,0,0,$this->waterImg_info[0],$this->waterImg_info[1],$pct);      }      private function waterstr() {          $rect = imagettfbbox($this->fontSize,0,$this->fontFile,$this->waterStr);          $w = abs($rect[2]-$rect[6]);          $h = abs($rect[3]-$rect[7]);          $fontHeight = $this->fontSize;          $this->water_im = imagecreatetruecolor($w, $h);          imagealphablending($this->water_im,false);          imagesavealpha($this->water_im,true);          $white_alpha = imagecolorallocatealpha($this->water_im,255,255,255,127);          imagefill($this->water_im,0,0,$white_alpha);          $color = imagecolorallocate($this->water_im,$this->fontColor[0],$this->fontColor[1],$this->fontColor[2]);          imagettftext($this->water_im,$this->fontSize,0,0,$this->fontSize,$color,$this->fontFile,$this->waterStr);          $this->waterImg_info = array(0=>$w,1=>$h);          $this->waterimg();      }      function output() {          $this->imginfo();          if ($this->waterType == 0) {              $this->waterstr();          }else {              $this->waterimginfo();              $this->waterimg();          }          switch ($this->srcImg_info[2]) {              case 3:                  imagepng($this->im,$this->srcImg);                  break 1;              case 2:                  imagejpeg($this->im,$this->srcImg);                  break 1;              case 1:                  imagegif($this->im,$this->srcImg);                  break 1;              default:                  die('添加水印失败！');                  break;          }          imagedestroy($this->im);          imagedestroy($this->water_im);      }  }  ?>