- getimagesize: documentation ( source)
- header: documentation ( source)
- fpassthru: documentation ( source)
- fopen: documentation ( source)
<?php
$size = getimagesize("http://i1-win.softpedia-static.com/screenshots/Nokia-Monitor-Test_1.png");
$fp = fopen($filename, "rb");
if ($size && $fp) {
header("Content-type: {$size['mime']}");
fpassthru($fp);
exit;
} else {
// error
}