Table 1 Comparison of chromatic coordinates measured experimentally and calculated from image analysis for clean and tarnished copper and silver coupons from Fig. 5.

79.66

73.44

74.01

76.71

64.92

70.22

63.36

64.91

14.30

12.83

19.87

14.09

24.83

25.10

28.00

25.68

15.10

17.47

13.69

15.34

42.03

48.74

36.50

45.40

91.87

79.60

80.87

81.06

72.44

74.92

66.87

68.45

0.10

0.20

2.35

−2.11

5.00

4.34

0.65

4.64

3.63

1.82

−0.63

0.91

26.82

31.19

26.81

26.55