An Image-Based Measurement of Lip Glossiness by Focusing on the Texture Design of Lip Rouge

Glossiness is one of the most important quality components of lip rouge. However, an objective and quantitative evaluation method has yet to be established. We aimed to develop a method for image-based lip glossiness measurement by focusing on the texture design of lip rouge, including “ pearly ” and “ glossy ” textures. Initially, the correlation between visual glossiness and the image statistic parameter “ skewness ”， which has been used in previous glossiness perception studies, was evaluated. Skewness showed a good correlation with the visual glossiness of glossy texture lip rouge （ correlation coefficient r ＝ 0.65 ）， though not with that of pearly texture lip rouge （ r ＝ 0.21 ）． Next, we developed a new image statistic parameter termed “ RMS contrast ”， which was consid-ered to have a good correlation with the visual glossiness of pearly texture lip rouge. To evaluate the efficacy of RMS contrast, image statistic parameters and visual glossiness scores of texture-enhanced lip rouges （ glossy, pearly, and matte ） were determined and compared. The present re-sults showed that skewness showed a good correlation with the glossiness of glossy lip rouge, while RMS contrast showed that with pearly lip rouge. In addition, use of a multiple regression equation with these two image statistic parameters allowed for effective evaluation of visual glossiness with good estimation accuracy （ r ＝ 0.82 ）．