ImageMagick - Powerful Programmatic Image Processing

ImageMagick is a free and open source software package for modifying and creating images. Unlike graphics packages such as The GIMP that provide tools for manual creation and manipulation of images, ImageMagick is meant to be used by programs to generate and adjust images automatically. Interfaces are available for many programming languages, including Ada, C, C++, Java, Lisp, Pascal, Perl, PHP, Python, Ruby, and Tcl/TK. It can also be used from the command line.

ImageMagick can read, write, and convert between some 100 different image file formats, including all commonly used ones such as GIF, JPEG, PDF, PNG, Postscript, and TIFF. Among the numerous capabilities of ImageMagick are image resizing, rotation, cropping, flipping, trimming, making parts of an image invisible, adding shapes or text to an image, various special effects, creating animated GIFs, combining images, and handling giga-pixel images.

This software works well on large images and makes it easy to automatically convert images into thumbnails. However, keep in mind that it creates large files in the /tmp directory that may be left behind if the program crashes.

Binary installation files for various operating systems are available here.