Re: "Discrete Hartley transform" vs " Discrete Fouuier transform"

>The DHT certainly has some interesting properties, and is a nice
>transform to think about from time to time.  (For example, in one of
>our own papers we showed that DHTs give a simple way to apply Rader's
>algorithm for prime-length transforms to purely real data, although
>Burrus in 1982 showed that there is a way to do this directly for real-
>data FFTs too.) But early claims of significant performance or memory
>advantages from FHT algorithms for power-of-two sizes have, sadly, not
>withstood the test of time.

Use Ron Mayer's algorithm from the early 1990's, the one with selectable 
trig tables and test it yourself. I've found that large FHT's are even
more 
of an advantage, compare maybe the best FFT and his FHT with 16384 data 
points.  Perhaps the saving comes out through thra****ng the memory in the 
convolutions, and maybe the trig tables are not accurate enough for your 
needs.
I know that doesn't sound very scientific, but trying everything out is
the 
only way you're going to know what to use....