You could store the image data encoded as something like Base64, and then decode it when you print it to file, like this:

#!perl
use strict;
use warnings;

use MIME::Base64;

my $data = < base64-encoded data here >;

open my $outfile, '>', 'file.gif' or die $!;

binmode $outfile;

print {$outfile} decode_base64($data);

close $outfile;
[download]

See the MIME::Base64 manpage for information about Base64 encoding, as well as examples of encoding files.

Update: Oops, sorry Grandfather, you were too quick for me.

Another Update: Link fixed.