#!/usr/bin/perl
use warnings;
use strict;
use Image::Magick;
use File::Basename;

my $image = Image::Magick->new;
umask 0022;
my @pics= <pics/*.jpg pics/*.gif pics/*.png>;
my @exts = qw(.jpg .gif .png);
   
foreach my $pic (@pics){    
   my ($basename,$path,$suffix) = fileparse($pic,@exts);   

   my $ok;
   $ok = $image->Read($pic) and warn ($ok);
   rename ($pic, "$pic.bak") or warn $!;
   my $resize = "$basename.jpg";
   
   $image->Scale(geometry => '500x500');
   $ok = $image->Write("pics/$resize") and warn ($ok);
   undef @$image; #needed if $image is created outside loop
   print "$pic ->resize to  pics/$resize\n";
}