Table 2.

Summary of parameters for texture features used (numbers in brackets signify how many features of each texture category were computed)

Feature	Parameters
Non-steerable gradient (17)	Sobel/Kirsch X,Y,Z and diagonal directions, gradient X,Y,Z directions and magnitude, 1st order statistics
Steerable gradient (48)	λ= {2.82,5.66,8.2,11.31,22.63,45.25} $(\frac{2^{2\dots 6}}{\sqrt{2}})$ θ = {0,0.39,0.78,1.18,1.57,1.96,2.36,2.75} $(0\dots 7\times \frac{\pi }{8})$
Second order statistical (13)	Entropy, energy, inertia, inverse difference moment, correlation, 2 information measures, sum average, sum variance, sum entropy, difference average, difference variance, difference entropy