In the last few years, as part of our activities for the Electronic Imaging Conference in SanFrancisco in January, we have always investigated the ACES pipeline at least in one paper.
Mostly it addressing problems related to the Input Device Transform (IDT) and last year Rec. 709 in - and outputs.
This year we looked at the new GamutCompressor algorithm.
Here is a link to the slightly revised live presentation video at the conference (about 18) minutes.
Here the complete paper can be downloaded.
Ebs_PAPER_2021_v07 (2).pdf (1.8 MB)
We concluded that it is one way to integrate the algorithm into the ACES modules without parameterization directly behind the IDT. However, on the other hand, it could also be useful to add the algorithm as a stand-alone operator in specific host programs. Here, the parameters could be accessible to the user:
Recommendations for implementation
As stated in section 1.2, the Compressor is intended to be inserted in the ACES pipeline after the Input Device Transform (IDT). The ACES system consists – to this moment – of modules that lack parameterization. To integrate all possible case studies, some settings have been made very broad, especially the Distance Limit values. Naturally, this means that certain production pipeline problems cannot be treated specifically.
The recommendation is therefore to consider two different implementation scenarios:
- Placing the GamutCompressor in the ACES pipeline with the default values directly after the Input Device Transform (IDT).
- Additionally, the algorithm could be implemented directly into an application as a Look Modification Transform (LMT); for VFX work, it could be The Foundry’s Nuke. To use this algorithm’s powerful functionality, the parameters should be exposed to the user. This allows exceptional cases to be explicitly handled that would cause artifacts in other cases. For such an operator inserted directly into the application, it would be helpful to display the image areas with the out-of-gamut colors. Furthermore, the CIE xy-chromaticity diagram could be useful as an additional analysis tool.