ImagePeriodogram

ImagePeriodogram[image]

shows the squared magnitude of the discrete Fourier transform (power spectrum) of image.

ImagePeriodogram[image,n]

shows the average of power spectra of non-overlapping partitions of size n×n.

ImagePeriodogram[image,n,d]

uses partitions with offset d.

ImagePeriodogram[image,n,d,wfun]

applies a smoothing window wfun to each partition.

ImagePeriodogram[image,n,d,wfun,m]

pads partitions with zeros to length m prior to the computation of the transform.

Details and Options

  • ImagePeriodogram logarithmically scales the power spectrum of the image and adjusts the values so that they range from 0 to 1.
  • In ImagePeriodogram[image,n,d,wfun], the smoothing window wfun can be specified using a window function that will be sampled between and , or a list of length n. The default window is DirichletWindow, which effectively does no smoothing.
  • ImagePeriodogram[image,n] is equivalent to ImagePeriodogram[image,n,n,DirichletWindow,n].
  • ImagePeriodogram[image,{n1,n2}] partitions image into blocks of size n1×n2.
  • For 3D images, ImagePeriodogram[image,{n1,n2,n3}] partitions image into blocks of size n1×n2×n3.
  • For multichannel images, ImagePeriodogram returns a multichannel image where each channel is the power spectrum computed for each channel separately.
  • ImagePeriodogram accepts the Alignment option that determines the location of the zero frequency term. The default is Alignment->Center. With Alignment->{Left,Top}, the zero frequency term is placed at the top-left corner of the image.

Examples

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Basic Examples  (3)

Power spectrum of an image of a disk:

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Power spectrum of a color image:

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Power spectrum of a 3D image of the hydrogen wave function:

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Options  (1)

Properties & Relations  (2)

See Also

PeriodogramArray  Periodogram  Fourier  SpectrogramArray  Spectrogram  DirichletWindow  Partition  ImagePartition

Introduced in 2012
(9.0)