TABLE 2.

Top‐ranked skin feature factors positively (Table 2A) or negatively (Table 2B) correlated with the stratum corneum moisture content in group 1. Table 2C shows the case of positively correlated skin feature factors in group 2. The skin feature factors were created by combining the skin features listed in Table S1 by the PolynomialFeatures(3) of scikit‐learn.

A
Positively correlated combined factor	Correlation coefficient
Brown spot count_VISIA * Pore count_VISIA^2	0.45
UV spot count_VISIA * Pore count_VISIA^2	0.45
UV pore count_VISIA * Brown spot count_VISIA * Pore count_VISIA	0.44
Brown spot count_VISIA^2 * Pore count_VISIA	0.44
UV spot count_VISIA^2 * Pore count_VISIA	0.43
Pore count_VISIA^3	0.43

B
Negative correlated combined factor	Correlation coefficient
Pore circularity (a.u.)_replica * Rough skin_visually assessed	−0.36
a*(a.u.) * Pore circularity (a.u.)_replica * Rough skin_visually assessed	−0.35
Rough skin_visually assessed	−0.34
Pore circularity (a.u.)_replica * Dark pore_visually assessed * Rough skin_visually assessed	−0.34
Pore angle SD(°)_replica * Rough skin_visually assessed	−0.34
Hemoglobin index (a.u.)_color difference * Pore circularity (a.u.)_replica * Rough skin_visually assessed	−0.34

C
Positively correlated combined factor	Correlation coefficient
Brown spot count_VISIA	0.31
Brown spot count_VISIA^2	0.28
Brown spot count_VISIA * Pore count_VISIA	0.28
Pore count_VISIA	0.27
Brown spot count_VISIA^3	0.25
Brown spot count_VISIA^2 * Pore count_VISIA	0.25