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  • 使用GD库做图片水印

      1. png图片作为水印加到其他类型图片后,背景变黑色 
        原因: imagecopy函数拷贝时可以保留png图像的原透明信息,而imagecopymerge却不支持图片的本身的透明拷贝。 
        然后直接上代码:
        /*
            * 功能:PHP图片水印 (水印支持图片或文字)
            * 参数:
            * $groundImage 背景图片,即需要加水印的图片,暂只支持GIF,JPG,PNG格式;
            * $waterPos 水印位置,有10种状态,0为随机位置;
            * 1为顶端居左,2为顶端居中,3为顶端居右;
            * 4为中部居左,5为中部居中,6为中部居右;
            * 7为底端居左,8为底端居中,9为底端居右;
            * $waterImage 图片水印,即作为水印的图片,暂只支持GIF,JPG,PNG格式;
            * $waterText 文字水印,即把文字作为为水印,支持ASCII码,不支持中文;
            * $textFont 文字大小,值为1、2、3、4或5,默认为5;
            * $textColor 文字颜色,值为十六进制颜色值,默认为#FF0000(红色);
            *
            * 注意:Support GD 2.0,Support FreeType、GIF Read、GIF Create、JPG 、PNG
            * $waterImage 和 $waterText 最好不要同时使用,选其中之一即可,优先使用 $waterImage.
            * 当$waterImage有效时,参数$waterString、$stringFont、$stringColor均不生效.
            * 加水印后的图片的文件名和 $groundImage 一样.
         
            */
            public static function FoximageWaterMark($groundImage,$waterPos=0,$waterImage="",$waterText="",$textFont=5,$textColor="#595959")
            {
                $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])//取得背景图片的格式
                    {
                        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*5.5),0,"0",$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;
                        $posY = $ground_h - $h;
                        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($isWaterImage)//图片水印
                {
                    // imagecopy函数拷贝时可以保留png图像的原透明信息,而imagecopymerge却不支持图片的本身的透明拷贝
                    imagecopy($ground_im, $water_im, $posX, $posY, 0, 0, $water_w, $water_h);
        //            imagecopymerge($ground_im, $water_im, $posX, $posY, 0, 0, $water_w,$water_h,20);//拷贝水印到目标文件
                }
                else//文字水印
                {
                    if( !empty($textColor) && (strlen($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!");
                    }
         
                 // imagettftext ($ground_im, 20,0, 20, 30, imagecolorallocate($ground_im, $R, $G, $B),base_url()."/water.ttf","麦言社区");
                    imagestring ( $ground_im, $textFont, $posX, $posY, $waterText, imagecolorallocatealpha($ground_im, $R, $G, $B,100));
                }
                //生成水印后的图片
                @unlink($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);
            }
        

          

          

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  • 原文地址:https://www.cnblogs.com/blog-dyn/p/6904232.html
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