Comprehensive color solutions: CAM16, CAT16, and CAM16‐UCS

TLDR

CIECAM02 is widely used but suffers computational failures in some applications, and existing fixes compromise accuracy. The authors aim to modify CIECAM02 by unifying color and luminance adaptation into a single space. They introduce CAM16, a revised model that performs adaptations in one space, and propose CAT16 and CAM16‑UCS as replacements for CAT02 and CAM02‑UCS. CAM16 resolves previous issues, matches or exceeds CIECAM02 accuracy, is simpler, and together with CAT16 and CAM16‑UCS offers a complete solution for color‑appearance prediction and color‑difference evaluation.

Abstract

Abstract The CIECAM02 color‐appearance model enjoys popularity in scientific research and industrial applications since it was recommended by the CIE in 2002. However, it has been found that computational failures can occur in certain cases such as during the image processing of cross‐media color reproduction applications. Some proposals have been developed to repair the CIECAM02 model. However, all the proposals developed have the same structure as the original CIECAM02 model and solve the problems concerned at the expense of losing accuracy of predicted visual data compared with the original model. In this article, the structure of the CIECAM02 model is changed and the color and luminance adaptations to the illuminant are completed in the same space rather than in two different spaces, as in the original CIECAM02 model. It has been found that the new model (named CAM16) not only overcomes the previous problems, but also the performance in predicting the visual results is as good as if not better than that of the original CIECAM02 model. Furthermore the new CAM16 model is simpler than the original CIECAM02 model. In addition, if considering only chromatic adaptation, a new transformation, CAT16, is proposed to replace the previous CAT02 transformation. Finally, the new CAM16‐UCS uniform color space is proposed to replace the previous CAM02‐UCS space. A new complete solution for color‐appearance prediction and color‐difference evaluation can now be offered.