46 Frizzy JOURNAL OF COSMETIC SCIENCE Figure 14. Continued. Table VI Quantification of Reflection Sites on Frizzy, Very Curly, and Curly Hair by Using Image Threshold Technique Total pixels Black pixels White pixels % Black % White 1,804,101 1,783,515 20,586 98.86 1.14 Very curly 921,160 905,242 15,918 98.27 1.73 Curly 636,629 622,296 14,333 97.75 2.25 2. Image analysis was employed to analyze random reflection patterns in untreated and modified African hair. In images of hair, all of the specular reflection sites have been isolated on a black background using an image threshold technique. This permitted us to count the total number of the brightest reflections, the number of which decreased significantly after treatment of hair with sebum. 3. Image analysis also allowed us to characterize quantitatively the luster of tresses with hair types characterized as frizzy, curly, and very curly. Curly and very curly hair was studied by measuring light-scattering profiles, which allowed for the calculation of specular/diffuse light intensities and luster parameters. All three types of hair were also studied using an image threshold technique, which permitted ranking them according to the absolute and relative content of specular reflections.
SPECULAR REFLECTION IN HAIR 47 In our subsequent work we would like to explore the effect of styling, conditioning, and special treatments on the luster of hair, utilizing mannequin or human model heads. We believe that digital photography and image analysis coupled with data analysis, similar to that presented in this paper, could lead to a quantitative luster evaluation in natural hair assemblies. REFERENCES (1) R. McMullen and J. Jachowicz, Optical properties of hair: Effect of treatments on luster as quantified by image analysis,]. Cosmet. Sci, 54, 335-351 (2003). (2) M. Zielinski, A new approach to hair surface topography: Fourier transform and fractal analysis,]. Soc. Cosmet. Chem., 40, 173-189 (1989). (3) S. Nagase, N. Satoh, and K. Nakamura, Influence of internal structure of hair fiber on hair appearance. II. Consideration of the visual perception mechanism of hair appearance,]. Cosmet. Sci., 53, 345-361 (2002) Proceedings of the 12th International Hair-Science Symposium of DWI, Heidelberg, Germany, September 2001. (4) G. Sendelbach, M. Haller, C. Springob, and H. Schmidt, Hair luster measurements via image analysis and its use for cosmetically altered hair, Proceedings of the 12th International Hair Science Symposium of DWI, Heidelberg, Germany, September 2001.
Previous Page Next Page