128 JOURNAL OF COSMETIC SCIENCE IMAGE ANALYSIS OF HAIR TREATED WITH STYLING PRODUCTS Roger McMullen and Janusz Jachowicz, Ph.D. International Speciality Products, Wliyne, New Jersey Introduction In a previous report [ 1 ], we described the measurements of luster for various types of hair by quantifying the intensity of light reflected from hair fibers spread over a cylindrical surface and illuminated with a collimated beam of light. Such an experimental set-up allows one to obtain reflected light distribution curves similar to those typically generated by goniophotometers. By analyzing the shape of the reflection curves and by calculating luster parameters we were able to investigate the effect of polymer and oil treatments on the luster of hair. In this paper we have explored the application of Image Analysis to analyze hair treated with complete cosmetic formulations such as hair gels, hair creams, hair sprays, and hair conditioners which were applied to hair in a manner similar to that employed by an average consumer. We have performed measurements on both idealized geometrical arrangements of straight hair spread over a cylindrical surface as well as on a free hanging hair tresses illuminated by a collimated light. Image analysis also allowed us to quantitatively characterize the luster of tresses with hair types characterized as frizzy, curly, and very curly hair before and after treatment with hair care products. Curly and very curly hair was studied by measuring light reflection 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. We have also used images of hair fibers spread over a cylindrical surface and illuminated with a collimated light to analyze subtle color changes in hair treated with colorless styling products. lbis was achieved using the image processing package, Adobe PhotoShop. Using such an approach, it is possible to obtain histograms of the various components of light (blue, red, and green as well as the total luminance) in an image obtained under strictly defined and reproducible illumination and geometrical conditions. Methods Hair Samples Luster analysis was performed on straight, natural light brown and dark brown hair of Caucasian origin purchased from IHI & Products, Inc. (Valhalla, NY). In addition to this, we utilized frizzy, curly, and very curly hair of Caucasian origin supplied by IHI & Products, Inc. (Valhalla, NY). Hair samples were pre­ cleaned with a 3 % ALS solution and thoroughly rinsed prior to experimentation. Luster Measurements The luster evaluation apparatus and procedures used in this study were described previously [l]. An Olympus Camedia ElO digital camera with a front-element auxiliary macro lens was employed to collect images of illuminated hair, typically one or two tresses, from a distance of IO inches. We scanned the light intensity parallel to the fiber axes of a hair tress by employing Image Analysis software (Sigma Scan Pro 5.0). Image Color Measurements Analysis of image histograms was accomplished by importing the images obtained for luster analysis into Adobe Photoshop 6.0. Histograms for luminosity, red, green, and blue were obtained and the positions of peak maxima were recorded. Results We sought to characterize the changes in luster and color produced by applying to hair a series of products which included a gel, hair spray, cream lotion, and a conditioner. The products caused a change in the intrinsic luster of hair as measured by a method involving the use of straight hair in circular configuration. This change was quantified by determining two well known luster parameters, Ls1amm and LRobblns-Reich, on both dark brown and light brown hair. The results suggested that the use of light brown hair can underscore the luster enhancing effect of films, deposited by cosmetic products, on the surface of hair.
2003 ANNUAL SCIENTIFIC MEETING Luster can be also affected by hair style geometry. Thus, we have also investigated the luster of hair in its natural configuration i.e. in the form of free hanging tresses before and after treatments with styling products. The hair types examined consisted of Caucasian frizzy, Caucasian very curly, and Caucasian curly hair. Using the products mentioned above, the luster of curly hair, for example, can be increased by reducing the nwnber of frizzies and increasing the concave and convex specular reflection which is intrinsic to the tress due to the curliness of the hair. Figure l provides an example of luster analysis performed on very curly hair. Figure 1. Plot of luminance as function of distance for very curly hair, where the outlined area in each image was used as the sampling area. Figure 2, on the other hand, illustrates the color analysis of a light brown hair image obtained under controlled illumination and geometry for straight hair spread on a cylinder. Histograms (plots of pixel quantity as a function of color value, which scale from 0 to 255) for red, green, and blue tones as well as luminosity were generated and the positions of peak maxima were recorded. It is demonstrated that different types of styling products can produce small optical effects on the surface hair leading to differences in hair coloration. Figure 2. Image histograms for untreated light brown hair. References [ l] R. McMullen and J. Jachowicz, "Optical properties of hair: Effect of treatments on luster as quantified by image analysis," J. Cosme!. &i., 54, 335-351 (2003). [2] R. McMullen and J. Jachowicz, "Optical Properties of Hair - Detailed Examination of Specular Reflection Patterns in Various Hair Types", J. Cosmet. Sci., accepted. 129
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