no effect as zero distance between different classes. Discrete degree is
very useful in hyperspectral classification. However, discrete degree
becomes meaningless as the class distance goes beyond one point.
To determine the statistical separability among classes for a given
band combination, Jeffries–Matusita (JM) distances are introduced
for separability measurement of hyperspectral data. The maximum
JM distances can be regarded as a relative gauge for the ambiguity
separation and therefore for the classes [27]. JM distances are defined
by the equation: