Table 2. Parameters for synthetic image datasets.

Index of dataset	Imposed mean	Imposed variance	Imposed skewness	Contrast range	Discrete levels
MED-1	${\displaystyle c_{\mu }}$	${\displaystyle c_{{\sigma }^2}}$	NA	${\displaystyle [c_{\mu }-\delta c,c_{\mu }+\delta c]}$	32
MED-2	${\displaystyle c_{\mu }}$	${\displaystyle c_{{\sigma }^2}}$	${\displaystyle c_{\gamma }}$	${\displaystyle [c_{\mu }-\delta c,c_{\mu }+\delta c]}$	32
MED-3	0	${\displaystyle c_{{\sigma }^2}}$	1.25	${\displaystyle [\text{-}\delta c,\delta c]}$	32
MED-4	0	${\displaystyle c_{{\sigma }^2}}$	1	${\displaystyle [\text{-}\delta c,\delta c]}$	32
MED-5	0	${\displaystyle c_{{\sigma }^2}}$	0.75	${\displaystyle [\text{-}\delta c,\delta c]}$	32
MED-6	0	${\displaystyle c_{{\sigma }^2}}$	0.5	${\displaystyle [\text{-}\delta c,\delta c]}$	32
MED-7	0	${\displaystyle c_{{\sigma }^2}}$	0.25	${\displaystyle [\text{-}\delta c,\delta c]}$	32
MED-8	0	${\displaystyle c_{{\sigma }^2}}$	−0.25	${\displaystyle [\text{-}\delta c,\delta c]}$	32
MED-9	0	${\displaystyle c_{{\sigma }^2}}$	−0.5	${\displaystyle [\text{-}\delta c,\delta c]}$	32
MED-10	0	${\displaystyle c_{{\sigma }^2}}$	−0.75	${\displaystyle [\text{-}\delta c,\delta c]}$	32
MED-11	0	${\displaystyle c_{{\sigma }^2}}$	-1	${\displaystyle [\text{-}\delta c,\delta c]}$	32
MED-12	0	${\displaystyle c_{{\sigma }^2}}$	−1.25	${\displaystyle [\text{-}\delta c,\delta c]}$	32
MED-13	0	${\displaystyle c_{{\sigma }^2}}$	NA	[-2.5, 2.5]	512
MED-14	0	${\displaystyle c_{{\sigma }^2}}$	${\displaystyle c_{\gamma }}$	[-2.5, 2.5]	512