Metamerism is a critical color phenomenon which can cause serious problems for products assembled by various parts. Customers generally expect all parts are color‐matched under different observing conditions. This article extends the concepts of illuminant and observer metamerism to observing‐condition metamerism, that is, objects are color‐matched under one observing condition but not under others. The color inconstancy of a single object is also expanded to be evaluated under multiple observing conditions. Moreover, four Waypoint (Wpt) Shift Manifold difference metrics are proposed to evaluate not only observing‐condition metamerism of metamers and paramers but also observing‐condition color inconstancy of single objects: The Mean Object Inconstancy Index (MOII), The Mean Object Color Difference (MMOCD), Object Metamer Index (OMI), and Object Hue Similarity Index (OHSI). Existing indices of metamerism and color inconstancy employ appearance matching using a Chromatic Adaptation Transform (CAT) and color difference formulas such as CIEDE76 or CIEDE2000. The proposed metrics utilize material matching based upon the Waypoint Material Adjustment Transform (Wpt‐MAT) and Euclidian color difference in the perceptually uniform Material Color Equivalency Space WLab. Conceptual comparisons between these approaches are discussed and evaluated. Additionally, computational evaluation results under observing conditions composed by 99 illuminants and 70 observers show that MOII provides a measure of color inconstancy for single objects, MMOCD provides a measure of metamerism between metamers and paramers with a generalized assessment of color difference between two objects, OMI provides a measure of paramers, and OHSI provides a quantitative measure of hue characteristics for different observing conditions.

中文翻译：

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WPT（航点）位移歧管差异度量用于评估不同的观察条件（观察者+光源）同色异谱和颜色不稳定性

同色异谱是一种严重的颜色现象，会对由各个部件组装的产品造成严重的问题。客户通常希望所有零件在不同的观察条件下颜色匹配。本文将发光体和观察者同色异谱的概念扩展到观察条件同色异谱，即对象在一种观察条件下是颜色匹配的，而在另一种观察条件下不是。还可以扩展单个对象的颜色不稳定性，以便在多个观察条件下进行评估。此外，提出了四个Waypoint（Wpt）移位歧管差异度量，不仅可以评估同聚物和对聚物的观察条件同色异谱，而且可以评估单个对象的观察条件颜色不一致性：均值对象不稳定性指数（MOII），均值对象色差（MMOCD），对象元单体索引（OMI），和对象色相相似性指数（OHSI）。现有的同色异谱和颜色不稳定性指数使用色适应转换（CAT）和色差公式（例如CIEDE76或CIEDE2000）进行外观匹配。拟议的度量标准利用了在视觉上统一的“材料颜色等效空间” WLab中基于航路点材料调整变换（Wpt-MAT）和欧几里得色差的材料匹配。讨论并评估了这些方法之间的概念比较。此外，在由99个光源和70个观察者组成的观察条件下的计算评估结果表明，MOII提供了单个对象的颜色不稳定性度量，MMOCD提供了对同聚物和对聚物之间的同色异谱度量，并对两个对象之间的色差进行了全面评估，