FourierMagnitudeImg
DESCRIPTION
Extracts the magnitude values of a frequency domain image into a
smaller array. Each magnitude is computed as the norm of a complex
number, sqrt ( R^2 + I^2 ). The output suppresses all zero imaginary
values to produce an array that has (NC/2 + 1) columns for an input of
NC columns. Thus the output array is not compatible for use with the
InverseFFTImg module. Instead, the output should be combined using
FourierMergeImg with a phase array output by FourierPhaseImg to give a
frequency domain image that can be transformed back into the time
domain. The input must be a frequency domain image in the packed
format produced by the ForwardFFTImg module (see format description in
ForwardFFTImg documentation). The Fourier transformation is discussed
in:
Digital Image Processing, Gonzales, R.C., Wintz, P.,
Addison Wesley, Second Edition, 1987, pp 61--137.
INPUTS
Port: Img In
Type: Lattice
Constraints: 1..3-D.
source frequency domain image
WIDGETS
OUTPUTS
Port: Img Out
Type: Lattice
Constraints: 1..3-D.
real magnitude image (compressed)
PROBLEMS
SEE ALSO
ForwardFFTImg
InverseFFTImg
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© The Numerical Algorithms Group Ltd,
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