🚀 go-pugleaf

>
>Does anyone know or have pointers to the literature or code about how
>to do multidimensional Hartley transforms (i.e., is it obvious that a

For another source of info use Bracewells "The Hartley Transform"
Oxford University Press 1986 ISBN 0-19-503969-6

There are programs in the back, but the in-place radix 2 program
is wrong (In my humble opinion).


>2D HT is the same as 2 1D HT's, or do I need some correction), and what
>the correlation and convolution theorems look like for multidimensional
>Hartley transforms?

NO! two 1D HT not equal to 1 2D HT. 
ie if the input function is Hermitian symmetric such that the FT of
the function is real, the real and imaginary components must be moved
around. ie if the input is a(x,y) + ib(x,y), i denotes imag part,
the input to the HT is: c(x,y) = a(x,y) - b(-x,y)

NB I cant remember offhand which component has the negative sign in
b(x,y).
>
Hope this helps.