#!/usr/bin/perl -w

use strict;

use Image::Magick;

sub make_thumb
{
  my $file = shift;
  my $thumb = shift;

  my $size = 100;   # image size; either width or height will be a 100
+ pixels (or both)

  my $img = new Image::Magick;
  $img->Read($file);

  my ($width, $height) = $img->Get("width", "height");

  if ($width > $height) {
    my $ratio = $size / $width;
    $height *= $ratio;
    $width = $size;
  } elsif ($height > $width) {
    my $ratio = $size / $height;
    $width *= $ratio;
    $height = $size;
  } else {
    $width = $size;
    $height = $size;
  }

  $img->Resize( width => $width, height => $height, blur => 1 );
  $img->Write($thumb);
}

make_thumb("/path/to/img.png", "/path/to/thumbnail.png");
[download]