Dreamwidth Development Training

This seems like it should be easy but I'm really stuck. I'm trying to dynamically display images - i.e. generate the image with a perl script and display it without saving it to the server.

This simple example works on my Heliohost server, but not on Dreamwidth (the example is from http://www.perlmonks.org/?node_id=18565):

--------test.shtml------------
<img src="test.cgi?size=100" alt="" />
------------------------------


--------test.cgi------------
#!/usr/bin/perl -w

use strict;
use CGI;
use GD;

my $cgi=new CGI;
my $cgi_size=$cgi-&gt;param('size') || '50';

print &quot;Content-type: image/gif\n\n&quot;;
my $gd=new GD::Image($cgi_size,$cgi_size);
my $blue=$gd-&gt;colorAllocate(0,0,255);
$gd-&gt;fill(0,0,$blue);
binmode STDOUT; #just in case we're on NT
print $gd-&gt;gif;
------------------------------


I'm stumped - has anyone got any ideas?