TABLE 4.

Structural Texture Features

Structural feature	Qualitative description	Mathematical description
Local Binary Pattern (LBP)	Intensity variation between a pixel and its neighboring pixels.	$LBP\left(x_c,y_c\right)=\sum _{p=0}^{P-1}q\left(I_p-I_c\right)2^P,\left(x_p,y_p\right)=\left[x_c+\mathit{\text{Qcos}}\left(\frac{2\pi p}{P}\right),y_c-\mathit{\text{Qsin}}\left(\frac{2\pi p}{P}\right)\right]$ Ic and Ip are gray-level intensity values for pixel (xc,yc) and pixel (xp,yp). q = indicator function, 0 for negative inputs and 1 for non-negative inputs.Q, P = parameters to set pixel neighborhood size, set to 1 and 8, respectively.39,40