Scaling perceived saturation

Two psychophysical experiments were conducted at North Carolina State University (NCSU) and Rochester Institute of Technology (RIT) to obtain replicated perceived saturation data from color normal observers on the order of one unit of saturation. The same 37 Munsell sample sheets, including up to four references that had similar perceived saturation but different hue, were used in both experiments. Different assessment methods included presenting either four references simultaneously or only one reference at a time to observers and obtaining judged saturation magnitudes for the given Munsell samples. Four saturation models comprising Sab*, Suv*, CIECAM02, as well as Richter/Lübbe, were tested. CIECAM02 gave the best prediction of saturation for data obtained at NCSU while Sab* outperformed other models for the RIT data. For the combined dataset, Sab*, the Richter/Lübbe, and CIECAM02-based saturation models exhibited comparable performances. The Standardized Residual Sum of Squares index was used to measure the inter- and intra-observer variability and goodness of fit. Inter- and intra-observer variability of assessments was smaller than or comparable to those reported for the typical color difference evaluation experiments.