PW L - Power spectrum - Log10 ||

(2/12/18)

PURPOSE

Generates full, unscrambled 0.5 * logarithm of the power spectrum from complex Fourier transform for 2-D or 3-D images. Reads either a real image/volume or its Fourier transform. The resulting data are real and can be displayed as a normal image. Note that the output can contain negative values. Parallelized for OMP Jan 2018.   Example.

SEE ALSO

PW [Power spectrum - Amplitudes of Fourier transform ||]
PW PH [Phase spectrum ||]
FT [Fourier Transform ||]
RO SD [Rotational average - single line output, doc file]

USAGE

.OPERATION: PW L

.INPUT FILE: IMG001
[Enter name of the image/volume. Can be a real image/volume or its Fourier transform.]

.OUTPUT FILE: POW001
[Enter the name of the file where 0.5*LOG10(power spectrum) is to be placed.]

NOTES

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

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

SUBROUTINES

PW2SDR, PW2SR, PW3SDR, PW3SR

CALLER

FOUR1 , FOUR1B