I made the changes I suggested and it runs on my server with my image:
http://www.keeline.com/marc.php
Here is the code as I have it:
<?php
ini_set('display_errors', 1);
error_reporting(E_ALL);
header("Content-type: image/png");
$img_handle = imagecreatefrompng("KnottsCableCarPostcard-1024.png");
$color = imagecolorallocate($img_handle, 100, 100, 100);
$ip = $_SERVER["REMOTE_ADDR"];
imagestring($img_handle, 3, 10, 9, "Wade's IP: $ip", $color);
imagepng($img_handle);
imagedestroy($img_handle);
?>
Once you have it working, I'd comment out the ini_set() and error_reporting()
functions. You will probably want to check to see that the image you are
marking even exists and that it is an image.
James