Table 1.

Modified definitions of Unser features.

Name	Modified computational formula
Mean	$f_{\mathrm{1}}=\frac{{\sum }_{\mathbf{x}\in \mathrm{\Omega }}s\left(\mathbf{x}\right)}{\mathrm{2}{N}_{\mathrm{\Omega }}}={\mathrm{\mu }}_{\mathrm{\Omega }}$
Variance	$f_{\mathrm{2}}=\frac{\mathrm{1}}{\mathrm{2}}\left(\frac{{\sum }_{\mathbf{x}\in \mathrm{\Omega }}{\left(s\left(\mathbf{x}\right)-\mathrm{2}{\mathrm{\mu }}_{\mathrm{\Omega }}\right)}^{\mathrm{2}}+{\sum }_{\mathbf{x}\in \mathrm{\Omega }}d{\left(\mathbf{x}\right)}^{\mathrm{2}}}{N_{\mathrm{\Omega }}}\right)$
Energy	$f_{\mathrm{3}}=\frac{{\sum }_{\mathbf{x}\in \mathrm{\Omega }}s{\left(\mathbf{x}\right)}^{\mathrm{2}}·{\sum }_{\mathbf{x}\in \mathrm{\Omega }}d{(\mathbf{x})}^{\mathrm{2}}}{N_{\mathrm{\Omega }}^{\mathrm{2}}}$
Correlation	$f_{\mathrm{4}}=\frac{\mathrm{1}}{\mathrm{2}}\left(\frac{{\sum }_{\mathbf{x}\in \mathrm{\Omega }}{\left(s\left(\mathbf{x}\right)-\mathrm{2}·{\mathrm{\mu }}_{\mathrm{\Omega }}\right)}^{\mathrm{2}}-{\sum }_{\mathbf{x}\in \mathrm{\Omega }}d{\left(\mathbf{x}\right)}^{\mathrm{2}}}{N_{\mathrm{\Omega }}}\right)$
Contrast	$f_{\mathrm{5}}=\frac{{\sum }_{\mathbf{x}\in \mathrm{\Omega }}d{(\mathbf{x})}^{\mathrm{2}}}{N_{\mathrm{\Omega }}}$
Homogeneity	$f_{\mathrm{6}}=\frac{{\sum }_{\mathbf{x}\in \mathrm{\Omega }}\left(\mathrm{1}/\mathrm{1}+d{(\mathbf{x})}^{\mathrm{2}}\right)}{N_{\mathrm{\Omega }}}$
Cluster shade	$f_{\mathrm{7}}=\frac{{\sum }_{\mathbf{x}\in \mathrm{\Omega }}{\left(s\left(\mathbf{x}\right)-\mathrm{2}{\mathrm{\mu }}_{\mathrm{\Omega }}\right)}^{\mathrm{3}}}{N_{\mathrm{\Omega }}}$
Cluster prominence	$f_{\mathrm{8}}=\frac{{\sum }_{\mathbf{x}\in \mathrm{\Omega }}{\left(s\left(\mathbf{x}\right)-\mathrm{2}{\mathrm{\mu }}_{\mathrm{\Omega }}\right)}^{\mathrm{4}}}{N_{\mathrm{\Omega }}}$