Table 5.

Relative frequencies and conditional relative frequencies of metameric pairs of surfaces in natural scenes, calculated with color-difference formula CMC⁠(1⁠:⁠c⁠),^{3, 27} adaptation model CMCCAT2000,²⁴ and nominal discrimination threshold ΔE^thr = 1.0^a

			Criterion degree of metamerism na
Illuminants	Scene	Estimate	0	1	2	3	4
25,000 K–4000 K	vegetated	unconditional	−2.98	−3.31	−4.14	−4.83	−5.52
			(0.37)	(0.31)	(0.47)	(0.64)	(0.93)
		conditional		−0.33	−1.16	−1.86	−2.48
				(0.19)	(0.54)	(0.78)	(1.01)
	nonvegetated	unconditional	−2.81	−3.24	−4.26	−5.16	−5.91
			(0.35)	(0.27)	(0.37)	(0.64)	(0.74)
		conditional		−0.42	−1.45	−2.31	−3.06
				(0.15)	(0.53)	(0.76)	(0.91)

^aOther details as for Table 4.