ABSTRACT This article describes a way to distinguish between two distinct components of light source–induced color shifts, base color shift and metameric color shift, to provide a more complete understanding of color rendition. Working within the existing framework of IES TM-30-18 and CIE 224:2017, it shows that base color shift varies smoothly with location in color space in a pattern that is determined by the spectral power distribution (SPD) of the light source. Patterns of smooth variation can often be approximated well with a low-order polynomial function. Here, a vector field model is presented, based on a second-order polynomial function. The polynomial coefficients are adjusted, for a given light source, to provide a least squares fit to the calculated color shifts of a standard set of color samples. The adequacy of this model was verified by comparing it to another approach for characterizing base color shift that is based on discretization of color space and a much larger set of color samples. Once the vector field model of base color shifts for a given light source is determined, the metameric color shifts can be calculated from the residuals and the distribution of those shifts can be statistically summarized. Based on this information, a metameric uncertainty index (Rt) is proposed to provide new information about a light source. In particular, it can be used to estimate the likelihood of noticeable metameric mismatches induced by a given light source, which could lead to improved predictions of the perceived color quality of light.

中文翻译：

---

用于表征颜色偏移和同色异谱失配的矢量场颜色再现模型

摘要 本文描述了一种区分光源引起的颜色偏移的两种不同成分的方法，即基色偏移和同色异谱颜色偏移，以提供对颜色再现的更完整理解。在 IES TM-30-18 和 CIE 224:2017 的现有框架内工作，它表明基色偏移随颜色空间中的位置平滑变化，该模式由光源的光谱功率分布 (SPD) 决定。平滑变化的模式通常可以用低阶多项式函数很好地近似。在此，基于二阶多项式函数提出了矢量场模型。对于给定的光源，多项式系数被调整，以提供对一组标准颜色样本的计算色移的最小二乘拟合。通过将其与另一种基于颜色空间离散化和更大的颜色样本集来表征基色偏移的方法进行比较，验证了该模型的充分性。一旦确定了给定光源的基色偏移的矢量场模型，就可以从残差计算同色异谱的颜色偏移，并且可以统计总结这些偏移的分布。基于此信息，提出了同色异谱不确定性指数 (Rt) 以提供有关光源的新信息。特别是，它可以用来估计由给定光源引起的显着同色异谱不匹配的可能性，这可以导致对感知的光颜色质量的改进预测。