SubHero,
<?php
$filename = 'virgo.jpg';
header('Content-Type: image/png');
list($width, $height) = getimagesize($filename);
$im = imagecreatetruecolor($width, $height);
$image = imagecreatefromjpeg($filename);
imagecopyresampled($im, $image, 0, 0, 0, 0, $width, $height, $width, $height);
imagepng($im);
?>