Basic Information on fft

Task: fft
Purpose: Fourier transform on image(s)
Categories: uv analysis, map making

        FFT is a MIRIAD task that performs a fast Fourier transform on
        an image.  If the input is a cube, then each plane is FFT'ed
        individually (i.e. this does not perform a 3D FFT).
 
        Blanked pixels in the input images are treated as zeroes.
        The input image dimensions will be padded to a power of two if
        necessary.
 
        The output of the FFT is normally complex-valued.  You can save
        it in any one of several ways -- as the real or imaginary part,
        or as the magnitude (amplitude) and phase.

Key: rin
        Input real image.  No default.

Key: iin
        Input imaginary image.  The default is a zero image.

Key: sign
        Sign of the exponent in the transform.  -1 gives a a forward
        transform, +1 an inverse transform.  The inverse transform
        applies 1/N scaling.  The default is a forward transform.

Key: center
        Origin of the transform.  If two values are given they are used
        as the origin in the x and y axis respectively.  If one value is
        given then it's used for the origin for both the x and y.  The
        default is the header value for CRPIX1 and CRPIX2 or N/2+1 if
        they are not present in the header.

Key: rout
        Output real image.  Default is not to write it

Key: iout
        Output imaginary image.  Default is not to write it.

Key: mag
        Output amplitude image.  Default is not to write it.

Key: phase
        Output phase image.  Default is not to write it.
 
Revision: 1.8, 2018/12/05 23:36:20 UTC