KPG1_FFTBD

Takes the inverse (Backward) FFT of a real image

Description:

The input array should hold a Fourier transform of a purely real image, in Hermitian format as produced by KPG1_FFTFD, or KPG1_HMLTD. The inverse FFT of this image is taken and returned in OUT.

Invocation

CALL KPG1_FFTBD( M, N, IN, WORK, OUT, STATUS )

Arguments

M = INTEGER (Given)
Number of columns in the input array.
N = INTEGER (Given)
Number of rows in the input array.
IN( M, N ) = DOUBLE PRECISION (Given)
The input array (a Fourier transform of a real image, stored in Hermitian format).
WORK( ∗ ) = DOUBLE PRECISION (Given)
Work space. This must be at least ( 3∗MAX( M, N ) + 15 ) elements long.
OUT( M, N ) = DOUBLE PRECISION (Returned)
The inverse FFT of the input array (a purely real image). Note, the same array can be specified for both input and output, in which case the supplied values are overwitten.
STATUS = INTEGER (Given and Returned)
The global status.