Blaksley Carl, Udodaira Kumiko, Nicolas Alexandre, Casolino Marco
L'Oréal Research & Innovation, Kawasaki, Kanagawa, Japan.
RIKEN, Wako, Saitama, Japan.
Front Chem. 2024 Sep 10;12:1400796. doi: 10.3389/fchem.2024.1400796. eCollection 2024.
The of a makeup foundation is a perceived attribute which is not captured by opacity or any other single optical property. As previous instrumental measurements do not allow us to consistently compare one product to another, we have begun exploring new parameters and analysis methods made available by hyperspectral imaging. Presumably, the coverage of makeup comes from the change in color, homogeneity, and evenness over the face after application, and the ability of the product to hide spots and other blemishes.
As a starting point to unravelling this complex topic, we define a homogeneity factor which measures the change in the homogeneity of the spectra using the distribution of spectral angles in the face. We likewise define a spectral shift factor which indicates the degree of spectral change after product application. To test these new parameters and the overall analysis method, we applied them to the HSI validation dataset which contains data for three makeup foundation products of different coverage levels applied to 9 models.
We find that correlates with the sensory ranking of coverage. Similarly, the parameter correlates with the visible color change induced by the product, and we can map the three products into distinct categories based on their effect on and .
Nevertheless, the homogeneity factor does not fully describe coverage, and in the variability in the product effect from model to model we find evidence that we must also account for the relative color difference between the model's skin tone and the product shade among other factors.
粉底液的遮瑕效果是一种可感知的属性，无法通过不透明度或任何其他单一光学特性来体现。由于之前的仪器测量方法无法让我们持续地将一款产品与另一款产品进行比较，我们已开始探索高光谱成像所提供的新参数和分析方法。据推测，妆容的遮盖效果源于涂抹后脸部颜色、均匀度和色泽的变化，以及产品遮盖斑点和其他瑕疵的能力。
作为解开这个复杂课题的起点，我们定义了一个均匀度因子，它利用脸部光谱角的分布来衡量光谱均匀度的变化。我们同样定义了一个光谱偏移因子，它表示涂抹产品后光谱变化的程度。为了测试这些新参数和整体分析方法，我们将它们应用于高光谱成像验证数据集，该数据集包含了应用于9名模特的三种不同遮瑕水平的粉底液产品的数据。
我们发现均匀度因子与遮瑕效果的感官排名相关。同样，参数与产品引起的可见颜色变化相关，并且我们可以根据这三种产品对均匀度因子和光谱偏移因子的影响将它们划分到不同类别。
然而，均匀度因子并不能完全描述遮瑕效果，而且在不同模特之间产品效果的变异性中，我们发现有证据表明，除其他因素外，我们还必须考虑模特肤色与产品色调之间的相对颜色差异。
