image_resizer_by_ratio

#!/usr/bin/perl -w
use strict;         # Enforce some good programming rules
use Image::Magick;  # Module for image processing

my $ratio       = 1/3;

my $image       = Image::Magick->new;    # create object
foreach (@ARGV) {
  opendir(DIR, $_) or die "Can't opendir $_: $!";
  while (defined(my $file = readdir(DIR))) {
    if ($file =~ m/.jpg$/i){        # skip if not a JPEG file
      my $path   = "$_/$file";

      ## Image processing
      $image    -> Read($path);
      my $width  = $image->Get('columns');
      my $height = $image->Get('height');
      $image    -> Resize(width  => ($width  * $ratio),
                          height => ($height * $ratio),
                          );
      $image    -> Write(filename    => $path);
      undef @$image;                # delete image
    }
  }
  closedir(DIR);
}