OpenEXR Color Management Proposal Online

by malducin

Lead Developer Florian Kainz has posted online ILM's OpenEXR color management proposal, presented at the SIGGRAPH 2004 "OpenEXR, Film and Color" Birds of a Feather meeting. Also during SIGGRAPH 2004, ILM announced the latest features of the file format.

Here is the announcement:

ILM's OpenEXR color management proposal, presented at the Siggraph 2004 "OpenEXR, Film and Color" Birds of a Feather meeting, is now available on the OpenEXR web site:

Thanks to all who came to the BoF meeting. Overall the response to the proposal was very encouraging. Of course there were some concerns and unanswered questions that will have to be addressed.

I would appreciate additional feedback on the proposal. (I will be out of the office for one or two weeks, so I probably won't respond to mail right away.)

Work on the color transformation language interpreter described in the proposal started a few weeks ago. We expect to have working software in a couple of months.


Which can also be found here:

OpenEXR Documentation

As far as the press release, the new features were announced in the mailing lists weeks ago (and several reported here as well), but you can read it here:

Industrial Light & Magic (ILM), a Lucasfilm Ltd. company, today announced the update to OpenEXR (, its pioneering open source extended dynamic range image file format. In a continuing effort to promote an open source industry standard for an extended dynamic range file format, ILM put considerable effort into this production-ready update.

New features include:

  • Support for tiled images, including mipaps and ripmaps.
  • New Pxr24 compressor contributed by Pixar Animation Studios
  • Support of high dynamic range YCA (luminance/chroma/alpha) images with subsampled chroma channels.
  • Abstracted file I/O allowing it to be used with interfaces other than C++'s iostreams.
  • New utilities for manipulating tiled images files.

"Since OpenEXR's original launch, there has been an overwhelming response to the file format", says Cliff Plumer, Chief Technology Officer at ILM. "We have seen the adoption of OpenEXR from organizations in the effects industry as well as the software, academic and even gaming communities. With this version we've incorporated some key features that we developed as well as the ongoing contributions and improvements by the development community."

OpenEXR is a 16 and 32.bit, floating file format with much greater dynamic range than existing 8- and 10-bit file formats. Though it does not require a graphics card, it is fully compatible with the floating-point pixel formats supported by the latest graphics hardware. Its lossless data compression achieves compression ratios of 2:1 for scanned film images. ILM originally implemented its own extended dynamic range file format EXR in the summer of 2000. EXR was battle tested on Harry Potter and the Sorcerer's Stone, Men in Black II, Gangs of New York and Signs with fantastic success. Since its inception has been used on such productions as The Hulk, Van Helsing, Pirates of the Caribbean: The CUrse of the Black Pearl, Harry Potter and the Prisoner of Azkaban and is currently being used on Star Wars: Episode III "Revenge of the Sith".

Thanks to for transcribing the press release.