PHP图片水印

发布时间 2023-05-05 11:47:13作者: 潘潘潘的博客
    /*
    * 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;
    *      $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;
    *      $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;
    *      $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 $groundImage 一样。
    */
    public function imageWaterMark($groundImage, $waterImage='', $waterText='', $waterPos=0, $textFont=5, $textColor='#000000', $watermark_margin)
    {
        $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。";
        // 字体
        $font = APP_PATH . "/addons/remoteimgdownload/public/fzfs.ttf";
        $isWaterImage = FALSE; // 是否为图片水印

        //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    = $water_info[1];//取得水印图片的高
            //取得水印图片的格式
            switch($water_info[2]) {
                case 1:$water_im = imagecreatefromgif($waterImage);break;
                case 2:$water_im = imagecreatefromjpeg($waterImage);break;
                case 3:$water_im = imagecreatefrompng($waterImage);break;
                default:
                    // return ['code'=>1, 'text'=>$formatMsg];
                    return $groundImage;
            }
        }

        //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

            //取得背景图片的格式
            switch($ground_info[2]) {
                case 1:$ground_im = imagecreatefromgif($groundImage);break;
                case 2:$ground_im = imagecreatefromjpeg($groundImage);break;
                case 3:$ground_im = imagecreatefrompng($groundImage);break;
                default:
                    // return ['code'=>1, 'text'=>$formatMsg];
                    return $groundImage;
            }
        } else {
            // return ['code'=>1, 'text'=>'需要加水印的图片不存在'];
            return $groundImage;
        }

        //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*2.5),0,$font,$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<$h) ) {
            // return ['code'=>1, 'text'=>('需要加水印的图片的长度或宽度比水印'.$label.'还小,无法生成水印!')];
            return $groundImage;
        }
        switch($waterPos) {
            case 0://随机
                $posX = rand(0,($ground_w - $w)) + $watermark_margin;
                $posY = rand(0,($ground_h - $h)) + $watermark_margin;
                break;
            case 1://1为顶端居左
                $posX = 0 + $watermark_margin;
                $posY = 0 + $watermark_margin;
                break;
            case 2://2为顶端居中
                $posX = ($ground_w - $w) / 2;
                $posY = 0 + $watermark_margin;
                break;
            case 3://3为顶端居右
                $posX = $ground_w - $w;
                $posY = 0 + $watermark_margin;
                break;
            case 4://4为中部居左
                $posX = 0 + $watermark_margin;
                $posY = ($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 + $watermark_margin;
                $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)) + $watermark_margin;
                $posY = rand(0,($ground_h - $h)) + $watermark_margin;
                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( !empty($textColor) && (strlen($textColor)==7) ) {
                $R = hexdec(substr($textColor,1,2));
                $G = hexdec(substr($textColor,3,2));
                $B = hexdec(substr($textColor,5));
            } else {
                // return ['code'=>1, 'text'=>'水印文字颜色格式不正确!'];
                return $groundImage;
            }

            imagettftext($ground_im, $textFont, 0, $posX, $posY, imagecolorallocatealpha($ground_im, $R, $G, $B, 80), $font, $waterText);
            
            // 下面是重复加水印的
            // $x=0;
            // while($x<=$ground_w) {
            //     $y=$ground_h;
            //     while($y>0){
            //         imagettftext($ground_im, $textFont, 0, $x, $y, imagecolorallocatealpha($ground_im, $R, $G, $B, '80'), $font, $waterText);
            //         $y=$y-200;
            //     }
            //     $x=$x+200;
            // }
        }

        //生成水印后的图片
        //@unlink($groundImage);
        $updateGroundImage = substr($groundImage, 0, -4).substr($groundImage,-4); // 记得修改直接替换掉
        // $updateGroundImage = substr($groundImage, 0, -4).'_sy'.substr($groundImage,-4); // 记得修改直接替换掉
        switch($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;
        }

        //释放内存
        if(isset($water_info)) unset($water_info);
        if(isset($water_im)) imagedestroy($water_im);
        unset($ground_info);
        $result = imagedestroy($ground_im);

        // return ['code'=>$result, 'pic'=>$groundImage];
        return $updateGroundImage;
    }