my $gifdir_name = "/home/tony/perl/pmbencor";
opendir my $gifdir_dh, $gifdir_name
    or die "Can't opendir '$gifdir_name': $!";
my @orig_files = grep { !/^\.\.?$/ } readdir $gifdir_dh;
closedir $gifdir_dh;

my $there = '/home/tony/perl/newdir';
mkdir $there, 0777  or die "Can't mkdir $there: $!";

my $key_pattern = join '|', map { quotemeta } keys %image_hash;

use File::Copy;  # this should really be at the top somewhere

foreach my $file (@orig_files) {
    my $new_name = $file;
    $new_name =~ s/($key_pattern)/$image_hash{$1}/g;
    move "$gifdir_name/$file", "$there/$new_name"
        or die "Can't move '$file' to '$new_name': $!";
}