Caching images generated by gd to memcahe_PHP tutorial

print?//Start caching images

          ob_start();//Enable output caching and temporarily cache the content to be output

Imagejpeg($newimage,false,$quality);//Output

          $data = ob_get_contents();//Get the cache just obtained

        ob_end_clean();//Clear the cache

         $mem =get_memcache();//Modify it yourself

           $mem->set($mem_key,$data,720000);//Save the output just obtained into memcache

          echo $data;//Output picture

          Then it’s displayed like this

         $mem = get_memcache();//Modify it yourself
$data = $mem->get($mem_key);

If($data) {

                 echo $data;

exit();

         }