<?php
$filename="images/thumb.jpg";
$fileInfo=getimagesize($filename);
$mime=$fileInfo['mime'];
$createfrom=str_replace('/','createfrom',$mime);
$outFun=str_replace('/',null,$mime);
$image=$createfrom($filename);
$red=imagecolorallocatealpha($image,255,0,0,60);
$fontfile='fonts/Doodle Camp.ttf';
imagettftext($image,30,0,0,30,$red,$fontfile,"水印");
header("content-type:.$mime;charset='utf-8'");
$outFun($image);
imagedestroy($image);