The Image::Size module for Perl provides a clean interface for fetching image dimensions (and type, when unknown) from graphics files in a wide variety of common formats. It is a pure Perl extension (no C or XS linking required) that has been tested on a variety of UNIX, Linux and BSD systems, as well as MacPerl and Windows ports of Perl. It was designed around and tuned for use in CGI application development, but is useful in other areas as well.
GSview is a graphical interface for Ghostscript, an interpreter for the PostScript page description language used by laser printers. For documents following the Adobe PostScript Document Structuring Conventions, it allows selected pages to be viewed or printed. GSview requires Ghostscript 7 or later.
AxPoint generates beautiful slideshows in PDF format from a simple XML description format. It is written as a Perl SAX2 handler, but also ships with command line tools. The format supports slide transitions, PDF bookmarks, bullet point transitions, images, text colours, different fonts, and more.
PhotoPnMTools is a simple toolkit for processing photographic images using improved algorithms. It is based on Poskanzer's PPM toolkit. It contains resizing, sharpening, and contrast / saturation / color balance filters. There is an interactive tool for cropping and color editing, and a tool for making Web albums.
Radiance is a set of tools which provide an advanced lighting simulation software package. It allows very detailed definition of materials' and light sources' properties through the use of advanced techniques like brdf and ies files, as well as a powerful mathematical scripting language, resulting in accurate renderings of scenes which are usually imported from CAD and 3D modelers. It uses the hybrid approach of Monte Carlo and deterministic ray tracing to achieve a reasonably accurate result in a reasonable time.