PW - Amplitudes of Fourier transform

PURPOSE

Generates full, unscrambled Fourier moduli from complex Fourier transform for 2-D or 3-D pictures. The input image can be real if it fits into the memory. Operation supports multiple radix FFT, thus the input image does not have to have power-of-two dimensions. The resulting data are real and can be displayed like a normal picture.

SEE ALSO

PW L	[Power spectrum - Log10]
FT	[Fourier Transform ||]

USAGE

.OPERATION: PW

.INPUT FILE: FOU001
[Enter the file name of the Fourier transform.]

.OUTPUT FILE: POW001
[Enter the name of the file where the Fourier transform amplitudes will be placed.]

EXAMPLE Usage

NOTES

1. The center of 2-D power spectrum is placed in (NX/2+1, NY/2+1);

2. The center of 3-D power spectrum is placed in (NX/2+1, NY/2+1, NZ/2+1).

3. The term |F(0)| is replaced by term |F(1)| to facilitate visualization.

SUBROUTINES

PW2SR, PW3SR

CALLER

FOUR1 , FOUR1B