Random pictures

The picture should update every 2 seconds:
##

#!/usr/bin/perl
use strict;
use GD;

# create a new image
my $im = new GD::Image(100,100);

# allocate some colors
my $white = $im->colorAllocate(255,255,255);
my $black = $im->colorAllocate(0,0,0);       
my $red = $im->colorAllocate(255,0,0);      
my $green = $im->colorAllocate(0,255,0);      
my $blue = $im->colorAllocate(0,0,255);

my @colors = ($red, $green, $blue);

# make the background transparent and interlaced
$im->transparent($white);
$im->interlaced('true');

# Put a black frame around the picture
$im->rectangle(0,0,99,99,$black);

# Draw a blue oval
$im->arc(50,50,95,75,0,360,$blue);

# And fill it with red, green, or blue
my $color = $colors[rand @colors];
$im->fill(50,50,$color);

# make sure we are writing to a binary stream
binmode STDOUT;

# Convert the image to PNG and print it on standard output
print "content-type: image/gif\n\n";
print $im->gif;