OpenEXR is a high dynamic-range (HDR) image file format developed by
Industrial Light & Magic for use in computer imaging applications.

OpenEXR is used by ILM on all motion pictures currently in production.
The first movies to employ OpenEXR were Harry Potter and the Sorcerers Stone,
Men in Black II, Gangs of New York, and Signs. Since then, OpenEXR has become
ILM's main image file format.

OpenEXR's features include:
* Higher dynamic range and color precision than existing 8- and 10-bit
  image file formats.
* Support for 16-bit floating-point, 32-bit floating-point, and 32-bit
  integer pixels. The 16-bit floating-point format, called "half", is compatible
  with the half data type in NVIDIA's Cg graphics language and is supported
  natively on their new GeForce FX and Quadro FX 3D graphics solutions.
* Multiple lossless image compression algorithms. Some of the included codecs
  can achieve 2:1 lossless compression ratios on images with film grain.
* Extensibility. New compression codecs and image types can easily be added
  by extending the C++ classes included in the OpenEXR software distribution.
  New image attributes (strings, vectors, integers, etc.) can be added to
  OpenEXR image headers without affecting backward compatibility with existing
  OpenEXR applications.

WWW: http://www.openexr.org/