# Table 1 Explanation of geometric and color variables studied

Classification Parameter Explanation
Geometry variables Area Lesion surface area, measured in cm2
Maximum diameter (MaxD) the longest line that joins two points on the border of the lesion, measured in cm
Perimeter Total boundary length of the region of interest (i.e., lesion), measured in cm
Circularity Ratio of the perimeter of the lesion divided by the perimeter of a circle with the same midpoint and same area as the lesion
Mean radius (Rm) Mean value of the lesion’s radii
Eccentricity Distance between color and geometric midpoint within the lesion
Color variables (values 0–255) Range of red, green, blue Range of values of red, green, blue intensity
Mean red, green, blue Mean value of red, green, blue intensity within the lesion
SD of red, green, blue Standard deviation of red, green, blue intensity within the lesion
CV of red, green, blue Expresses the standard deviation of red, green, blue intensity values as mean percentage
Skewness from Gaussian curve (red, green, blue) Deviation of each color’s histogram from the normal distribution curve 