FourierPhaseImg
DESCRIPTION
Extracts the phase values of a frequency domain image into a smaller
array. Since each phase is a real number derived from complex input,
the output array has approximately half the amount of useful data of
the input. The output compresses all phases 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
magnitude array output by FourierMagnitudeImg 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 and the cross correlation
are 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.
phase values (compressed)
PROBLEMS
SEE ALSO
ForwardFFTImg
InverseFFTImg
FourierMergeImg
FourierMagnitudeImg
[
Documentation Home ]
© The Numerical Algorithms Group Ltd,
Oxford UK. 1996