This is from a small test script I wrote yesterday. It creates a thumbnail while retaining image proportions. 
#!/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]

In reply to (ar0n) Re: creating thumbnails by ar0n
in thread creating thumbnails by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.