Table 3.

Description of intensity and texture features used to constructed the feature set F(c).

Feature	Description	Formulation
Intensity	Intensity value	f̃(c)
Mean	Average intensity value within neighborhood 𝒩(c).	$\overline{f}(c)=\frac{1}{|𝒩(c)|}{\sum }_{d\in 𝒩(c)}\tilde{f}(d)$
Median	Median intensity value within neighborhood 𝒩(c).	$\underset{d\in 𝒩(c)}{\text{median}}(\tilde{f}(d))$
Range	Range of intensity values within neighborhood 𝒩(c).	$\underset{d\in 𝒩(c)}{\text{max}}(\tilde{f}(d))-\underset{d\in 𝒩(c)}{\text{min}}(\tilde{f}(d))$
Variance	Variance of a Gaussian distribution of intensity values within 𝒩(c).	${\tilde{f}}_{\sigma }(c)=\sqrt{\frac{1}{|𝒩(c)|}}{\sum }_{d\in 𝒩(c)}{(\tilde{f}(d)-\overline{f}(c))}^2$
Rayleigh Variance33	Variance of the Rayleigh distribution calculated within the neighborhood 𝒩(c).	$f_{\widehat{\sigma }}(c)=\sqrt{\frac{1}{2|𝒩(c)|}}{\sum }_{d\in 𝒩(c)}{\tilde{f}\left(d\right)}^2$
m-parameter34	The m-parameter of the Nakagami distribution, which controls the shape of the distribution, calculated within the neighborhood 𝒩(c).	We use the method of Greenwood and Durand 35 to estimate m.