Hartley Transform

The equations for discrete Hartley transform and its inverse are:

H(f )= $\displaystyle {\frac{{1}}{{N}}}$$\displaystyle \sum_{{t=0}}^{{N-1}}$F(t)cas(2πft/N) (1)
and

X(t) = $\displaystyle \sum_{{f=0}}^{{N-1}}$H(f )cas(2πft/N) (2)
where cas(2πft) = cos(2πft) + sin(2πft). These are similar to those for the discrete Fourier Transform.