High Dynamic Range images under Linux (linux.com)
Linux.com has an introduction to high-end image formats and how they are supported with free software. "
OpenEXR was developed by Industrial Light and Magic and released under a modified BSD license in 2003. It supports 16-bit floating point, 32-bit floating point, and 32-bit integer pixels. It covers more than the entire visible color spectrum, and more than 10 orders of magnitude in brightness."