Comments on "Basis-restricted transformations and performance measures for spectral representations" by Pearl, J.

In this correspondence, we comment on some of the shortcomings, for source encoding problems, of the measure of distance between orthonormal representations proposed by Pearl.^1We further examine, using rate-distortion theory, whether rates achievable for a given distortion level by the use of basis-restricted transformations have some inherent dissimilarity independently of input statistics and of other implied parameters.