Table 2.

List of features used in the classifier.

	Feature	Description
1	Attenuation coefficients (mean)	Mean value of attenuation coefficient
2	Attenuation coefficients (std)	Standard deviation of attenuation coefficient
3	Penetration depth (mean)	Mean value of penetration depth
4	Penetration depth (std)	Standard deviation of penetration depth
5	Std filter value (mean)	Mean value of standard deviation filtering results
6	Std filter value (std)	Standard deviation value of standard deviation filtering results
7	Range filter (mean)	Mean value of range filtering results
8	Range filter (std)	Standard deviation value of range filtering results
9	Entropy	Entropy of the pixel values
10	Coarseness (TCN)	Coarseness analysis of texture code number
11	Homogeneity (TCN)	Homogeneity feature of texture code number
12	Contrast (GLCM)	Contrast feature from GLCM
13	Energy (GLCM)	Energy feature from GLCM
14	Distance to surface	The distance between the center of the layer and the surface
15	Skewness	Skewness within the whole layer
16	Kurtosis	Kurtosis within the whole layer