Part 1: The History

At Siggraph 2004, Florian Kainz presented ILM’s proposal for a color transform language to be used in conjunction with OpenEXR. Also at Siggraph, a Birds of a Feather meeting, organized by Lars Borg as part of his work with the ICC (International Color Consortium), discussed color management for film. [The ICC, established in 1993 by eight industry vendors, had the goal of “creating, promoting and encouraging the standardization and evolution of an open, vendor-neutral, cross-platform color management system architecture and components.”]
By 2004, post professionals were increasingly aware of the limitations posed by the Cineon and DPX file formats, the de facto industry standards. Though the relevant equipment being manufactured was powerful, it was also largely proprietary, creating a logjam of incompatibility.

In response, the Advanced Technology Committee of the Academy’s Science and Technology Council initiated the Interchange Format Project, with the goal of creating an interchange format that would allow for digital color management for motion picture production/post.

According to Illusion Arts’ Richard Patterson, RFX president/founder Ray Feeney chose Jim Houston to chair the committee, and key technical experts were recruited from all the major DI and visual effects facilities as well as animation production companies, film manufacturers (Kodak and Fuji), and ICC color scientists.

The first act was to commission a white paper from Ed Giorgianni, one of the principle architects of the PhotoCD and Cineon systems and co-author of the definitive “Digital Color Management” text. The white paper laid out a scheme: “Up until that point, the main discussion was whether OpenEXR could be proposed as the solution,” says Patterson. “There was a resistance for a variety of reasons, some technical, some logistical. To some extent a lot of it was the fact that this had to be an affordable and realistic proposal. Any facility set up around DPX and Cineon files would have to retool to change to OpenEXR files.”

Currently, says Patterson, the committee has determined that any interchange system will be based on linear colorimetric data, not printing-density values, which relate only to specific films. “Cineon files don’t really tell you what the color is, unless you can interpret the density,” he says. “There was never any strict colorimetry involved. All they were concerned about was a closed loop to scan and record. The color science behind it wasn’t explicit, so everyone came up with his or her own interpretation, and that’s where the problem came from.”

Stay tuned for Part 2 in next month’s DI Studio e-newsletter.

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