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 ( R2 + I2 ). 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
Digital Image Processing, Gonzales, R.C., Wintz, P.,
Addison Wesley, Second Edition, 1987, pp 61--137.
Port: Img In
Source frequency domain image.
Port: Img Out
Real magnitude image (compressed).
© The Numerical Algorithms Group Ltd, Oxford UK. 2000