use Term::ProgressBar;

my $progress = Term::ProgressBar->new({name  => 'Scaling images',
    count => scalar @imgfiles,
    ETA   => 'linear'});

# update ETA once per second at most
$progress->max_update_rate(1);

foreach (@imgfiles) {
    perform_imaging_ops($_);

    $progress->update();
}

##</code><code>##

crenz@tiffy:~ > scaleimages /my/directory
Scaling images:  19% [=========                                        ]ETA  23:35

##</code><code>##

Scaling images:  92% [============================================     ]5m14s Left