PHP给图片加水印教程

PHP给图片加水印相对ASP来说，要简单多了，看下面代码：

/*****************************************************

参数说明:

$max_file_size : 上传文件大小限制, 单位BYTE

$destination_folder : 上传文件路径

$watermark : 是否附加水印(1为加水印,其他为不加水印);

使用说明:

1. 将PHP.INI文件里面的"extension=php_gd2.dll"一行前面的;号去掉,因为我们要用到GD库;

2. 将extension_dir =改为你的php_gd2.dll所在目录;

3. http://www.knowsky.com/php.asp;

****************************************************/

//上传文件类型列表

$uptypes=array(

'image/jpg',

'image/jpeg',

'image/png',

'image/pjpeg',

'image/gif',

'image/bmp',

'image/x-png'

);

$max_file_size=2000000; //上传文件大小限制, 单位BYTE

$destination_folder="uploadimg/"; //上传文件路径

$watermark=1; //是否附加水印(1为加水印,其他为不加水印);

$watertype=1; //水印类型(1为文字,2为图片)

$waterposition=1; //水印位置(1为左下角,2为右下角,3为左上角,4为右上角,5为居中);

$waterstring="http://www.xplore.cn/"; //水印字符串

$waterimg="xplore.gif"; //水印图片

$imgpreview=1; //是否生成预览图(1为生成,其他为不生成);

$imgpreviewsize=1/2; //缩略图比例

?>

  上传文件:
 
 

  允许上传的文件类型为:=implode(', ',$uptypes)?>

if ($_SERVER['REQUEST_METHOD'] == 'POST')
{
    if (!is_uploaded_file($_FILES["upfile"][tmp_name]))
    //是否存在文件
    {
         echo "图片不存在!";
         exit;
    }
    $file = $_FILES["upfile"];
    if($max_file_size     //检查文件大小
    {
        echo "文件太大!";
        exit;
    }
    if(!in_array($file["type"], $uptypes))
    //检查文件类型
    {
        echo "文件类型不符!".$file["type"];
        exit;
    }
    if(!file_exists($destination_folder))
    {
        mkdir($destination_folder);
    }
    $filename=$file["tmp_name"];
    $image_size = getimagesize($filename);
    $pinfo=pathinfo($file["name"]);
    $ftype=$pinfo['extension'];
    $destination = $destination_folder.time().".".$ftype;
    if (file_exists($destination) && $overwrite != true)
    {
        echo "同名文件已经存在了";
        exit;
    }
    if(!move_uploaded_file ($filename, $destination))
    {
        echo "移动文件出错";
        exit;
    }
    $pinfo=pathinfo($destination);
    $fname=$pinfo[basename];
    echo " 已经成功上传
文件名: 
".$destination_folder.$fname."
";
    echo " 宽度:".$image_size[0];
    echo " 长度:".$image_size[1];
    echo "
大小:".$file["size"]." bytes";
    if($watermark==1)
    {
        $iinfo=getimagesize($destination,$iinfo);
        $nimage=imagecreatetruecolor($image_size[0],$image_size[1]);
        $white=imagecolorallocate($nimage,255,255,255);
        $black=imagecolorallocate($nimage,0,0,0);
        $red=imagecolorallocate($nimage,255,0,0);
        imagefill($nimage,0,0,$white);
        switch ($iinfo[2])
        {
            case 1:
            $simage =imagecreatefromgif($destination);
            break;
            case 2:
            $simage =imagecreatefromjpeg($destination);
            break;
            case 3:
            $simage =imagecreatefrompng($destination);
            break;
            case 6:
            $simage =imagecreatefromwbmp($destination);
            break;
            default:
            die("不支持的文件类型");
            exit;
        }
        imagecopy($nimage,$simage,0,0,0,0,$image_size[0],$image_size[1]);
        imagefilledrectangle($nimage,1,$image_size[1]-15,80,$image_size[1],$white);
        switch($watertype)
        {
            case 1:   //加水印字符串
            imagestring($nimage,2,3,$image_size[1]-15,$waterstring,$black);
            break;
            case 2:   //加水印图片
            $simage1 =imagecreatefromgif("xplore.gif");
            imagecopy($nimage,$simage1,0,0,0,0,85,15);
            imagedestroy($simage1);
            break;
        }
        switch ($iinfo[2])
        {
            case 1:
            //imagegif($nimage, $destination);
            imagejpeg($nimage, $destination);
            break;
            case 2:
            imagejpeg($nimage, $destination);
            break;
            case 3:
            imagepng($nimage, $destination);
            break;
            case 6:
            imagewbmp($nimage, $destination);
            //imagejpeg($nimage, $destination);
            break;
        }
        //覆盖原上传文件
        imagedestroy($nimage);
        imagedestroy($simage);
    }
    if($imgpreview==1)
    {
    echo "
图片预览:
";
    echo "height=".($image_size[1]*$imgpreviewsize);"
    echo " alt=\"图片预览:\r文件名:".$destination."\r上传时间:\" />";
    }
}
?>