ImageMagick is an extremely featureful image manipulation and conversion program that has the added benefit of being able to be run from the command line. Islandora uses ImageMagick to manipulate PDFs, as well as to create derivatives of large images.
ImageMagick is made up of two components:
Download links for both are provided below.
Binary releases for ImageMagick are available from the official site here: http://www.imagemagick.org/script/binary-releases.php
Please consult the ImageMagick documentation for installation instructions.
The Drupal ImageMagick module can be found at the project page, here: http://drupal.org/project/imagemagick
The ImageMagick module needs to be installed and configured before it can be used with Islandora. Specifically, you need to know where ImageMagick's 'convert' binary is found on your server. Please consult the ImageMagick module's page for further instructions.
The ImageMagick configuration page can be found at http://path.to.your.site/admin/config/media/image-toolkit