36 JOURNAL OF COSMETIC SCIENCE A B Figure 5. Images of (A) virgin dark brown and (B) natural white hair at close proximity. Exposure settings: f8, 1/13s. 300 250 GI 200 C C 150 .E 100 50 a a 5 10 15 20 25 30 Distance (rnn) Figure 6. Example of luminosity analysis horizontal to the fiber axes with a plot of luminance-vs-distance for one of the horizontal lines. Several possibilities exist as to the origin of these reflection patterns. le has been shown by profilomecry that the topology of hair along the fiber axis consists of a wave-like structure with alternating maxima and minima (2). Another possible source of the complex reflection pattern may be attributed to the twisting of the fibers. Since the fibers are elliptical, reflection from the larger face may cause greater reflectivity than chat
70 60 50 CJ 40 u.. 30 20 10 0 A 70 60 50 ! 40 LL 30 20 10 B SPECULAR REFLECTION IN HAIR 0 0 200 Luminance 200 Luminance 37 400 400 Figure 7. Example histograms displaying the frequency of appearance for (A) peak maxima and (B) peak minima that occur in one of the horizontal lines in Figure 6.
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