Heres the script im working with.
<?php
function createthumb($name,$filename,$new_w,$new_h)
{
global $gd2;
$system=explode(".",$name);
if (preg_match("/jpg|jpeg/",$system[1]))
{
$src_img=imagecreatefromjpeg($name);
}
if (preg_match("/png/",$system[1]))
{
$src_img=imagecreatefrompng($name);
}
$old_x=imageSX($src_img);
$old_y=imageSY($src_img);
if ($old_x > $old_y)
{
$thumb_w=$new_w;
$thumb_h=$old_y*($new_h/$old_x);
}
if ($old_x < $old_y)
{
$thumb_w=$old_x*($new_w/$old_y);
$thumb_h=$new_h;
}
if ($old_x == $old_y)
{
$thumb_w=$new_w;
$thumb_h=$new_h;
}
if ($gd2=="")
{
$dst_img=ImageCreate($thumb_w,$thumb_h);
imagecopyresized($dst_img,$src_img,0,0,0,0,$thumb_w,$thumb_h,$old_x,$old_y);
}
else
{
$dst_img=ImageCreateTrueColor($thumb_w,$thumb_h);
imagecopyresampled($dst_img,$src_img,0,0,0,0,$thumb_w,$thumb_h,$old_x,$old_y);
}
if (preg_match("/png/",$system[1]))
{
imagepng($dst_img,$filename);
}
else
{
imagejpeg($dst_img,$filename);
}
imagedestroy($dst_img);
imagedestroy($src_img);
}
?>