A class of generalized radiances characterized by filter functions was
recently introduced into the statistical wave theory via the phase-sp
ace representations of the cross-spectral density operator. It is show
n that if the generalized radiances are represented as linear transfor
mations of the cross-spectral density, there exists a unique correspon
dence between the filter functions and the transform kernels within ce
rtain galilean invariant transformations. Explicit expressions are der
ived for this correspondence, and the radiometric meanings of the cons
traints placed on the phase-space filter functions are elucidated.