42 A B JOURNAL OF COSMETIC SCIENCE I ,20 .e ! 100 f B O i. 60 :J 40 o+--------.------.--------.-----.----.-------1 0 40 --------------convex1Peak Peak2 convex Peak 3 60 Distance (mm) -----------------concave Peak4 --------------+----+---+-CODVCX Peak 5 -----------------------concave 160 140 I 120 .! ! 100 I 8 0 E so 40 20 20 40 60 80 100 Distance (mm) 100 120 120 140 Figure 13. Examples of hair with various types of curvature: (A) frizzy hair, (B) very curly hair, and (C) curly hair. Plots of luminance as a function of distance are provided for each hair type, where the outlined area in each image was used as the sampling area.

C SPECULAR REFLECTION IN HAIR Peak 1 -----------convex Peak 2 �-◄---------+---concave Peak 3 --------------+--convex Peak4 --------+---�----+--concave Distam:e(mmt Figure 13. Continued. Table V 43 Luster Parameters Calculated From Images of Curly and Very Curly Hair Shown in Figures 13B and 13C Luster parameter Peak 1 Peak 2 Peak 3 Peak 4 Peak 5 Curly hair Integrated specular intensity 33010 6653 17768 13283 22234 Integrated diffuse intensity 22579 5926 11544 11544 17508 Stamm's luster 0.32 0.11 0.35 0.13 0.21 Very curly hair Integrated specular intensity 15435 14141 13581 10314 Integrated diffuse intensity 10270 9742 8749 7345 Stamm's luster 0.33 0.31 0.36 0.29 As shown in Table IV, the number of reflections decreases with increasing concentrations of sebum, which was also clearly evident after visual inspection of Figure 12. It should also be added that the reflection shapes could be also characterized in terms of perimeter, roundness, compactness, etc. While we conducted such an analysis in relation to African hair, we did not find any obvious correlations between such parameters and the hair treatments.