#!/usr/bin/perl
use strict;
use Dumpvalue;
my $dumper = new Dumpvalue;

my $url_string = "http://www.made_up_name.com/image.jpg there might be text between as well since an url like so: http://www.made_up_name.com/image2.gif says to me this might be needed in a larger context so lets try with a string http://www.made_up_name.com/image3_the%20third.png and see what we get.";
my @images = map{split/\//;pop @_} $url_string =~ m!(http://\S+/\S+\.[a-z]{3,4})!g;
$dumper->dumpValues(\@images);
exit;

OUTPUTS:
0 ARRAY(0x155ac4c)
    0 'image.jpg'
    1 'image2.gif'
    2 'image3_the%20third.png'