Ghostscript is a processor for PostScript and PDF files. It can rasterize these files to a wide variety of printers, devices for screen preview, and image file formats. Since applications tend to prepare pages for printing in a high-level format such as PostScript, most Unix users with low-level bitmap printers, such as inkjets, use GhostScript as part of the printing process. In addition, Ghostscript is capable of converting PostScript files, functionality comparable to Adobe Acrobat Distiller, but on the command line. In addition, Ghostscript is used for file import and viewing by a great many other applications, including xv, ImageMagick, gimp, and xdvi. Several GUI wrappers for viewing PostScript and PDF files exist, including GSview, ghostview, gv, ggv, and kghostview. This is far from a comprehensive list.
BRL-CAD is a powerful constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing support for rendering and geometric analysis, path-tracing for realistic image synthesis, network distributed framebuffer support, and image and signal-processing tools.
The Geospatial Data Abstraction Library (GDAL) is a unifying C/C++ API for accessing raster geospatial data, and currently includes formats like GeoTIFF, Erdas Imagine, Arc/Info Binary, CEOS, DTED, GXF, and SDTS. It is intended to provide efficient access, suitable for use in viewer applications, and also attempts to preserve coordinate systems and metadata. Python, C, and C++ interfaces are available.
ICCLIB implements support for reading and writing of color profile files that conform to the International Color Consortium (ICC) Profile Format Specification, Version 3.4. The ICC Profile Format is a cross-platform device profile format that can be used to translate color data created on one device into another device's native color space. See the profile specification at color.org. In summary ICCLIB provides support for all version 3.4 header elements, Tags, and Tag Types, conversion to/from machine native representation of all data types, user-defined Tags, adding/deleting Tags, Tag type sharing within a file (often used for sharing LUTs amongst intents), reading/writing embedded profiles, a single function for transforming color values through a profile (including support for intents, forward and reverse transforms, gamut lookup or preview lookup), support and code examples for creating all profile types, monochrome, matrix, and Lut, and it loads Tag Types on demand to conserve memory space.
Ilib is an image manipulation library for developers. It's capable of reading and writing images (PPM/PGM, PNG, JPEG, GIF, XPM, BMP) and many drawing functions including drawing lines and text using any BDF (X11) font. It's great for generating GIFs/PNGs from a CGI or generating graphs. Ilib includes sample applications for generating graphs for HTTP access.log files and QuakeWorld server frag log files and a tool for creating image indices from a group of images.
Java PictDraw is a set of Java classes to display Quickdraw images (Macintosh Pict files). Quickdraw is a meta/vector format that supports lines, circles, arcs, boxes, polygon, styled text, bitmap-based regions, and compressed bitmaps (RLE and JPEG). This package contains all the classes needed to parse a Quickdraw file, and to display into a Java AWT port. Features include the ability to make the text regions of the picture clickable.