({{, (RefLink[Cepstrogram, paclet:ref/Cepstrogram])[data] 
plots the array of power cepstra computed on each partition of data.}, {, (RefLink[Cepstrogram, paclet:ref/Cepstrogram])[data,n] 
uses partitions of length n.}, {, (RefLink[Cepstrogram, paclet:ref/Cepstrogram])[data,n,d]
uses partitions with offset d.}, {, (RefLink[Cepstrogram, paclet:ref/Cepstrogram])[data,n,d,wfun]
applies a smoothing window wfun to each partition.}, {, (RefLink[Cepstrogram, paclet:ref/Cepstrogram])[data,n,d,wfun,m]
pads partitions with zeros to length m prior to the computation of the transform.}})

OpenersNotesSection(Spacer1)Details and Options

Cepstrogram computes and plots an array of cepstra computed on partitions of data.

The power cepstrum for each partition is computed as the squared inverse Fourier transform of the log-power spectrum.

Use (RefLink[CepstrogramArray, paclet:ref/CepstrogramArray]) to get the numerical array of cepstra.

The partition length n and offset d can be expressed as an integer number (interpreted as number of samples) or as time or sample quantities.

(RefLink[Cepstrogram, paclet:ref/Cepstrogram])[list] uses partitions of length n=2^Round[(Subscript[log, 2])((Sqrt[m]))+1] and offset d=Round[n/3], where m is (RefLink[Length, paclet:ref/Length])[list].

In (RefLink[Cepstrogram, paclet:ref/Cepstrogram])[list,n,d,wfun], the smoothing window wfun can be specified using a window function that will be sampled between -1/2 and 1/2 or a list of length n. The default window is (RefLink[DirichletWindow, paclet:ref/DirichletWindow]), which effectively does no smoothing.

The data can be any of the following:

For multichannel audio objects, the cepstrogram is computed over the sum of all channels.

(RefLink[Cepstrogram, paclet:ref/Cepstrogram]) accepts all (RefLink[Graphics, paclet:ref/Graphics]) options with the following additions and changes:

OpenersPrimaryExamplesSection(Spacer1)Examples  (8)

OpenersExampleSection0(Spacer1)Basic Examples  (2)

Cepstrogram of a sawtooth chirp signal:

Cepstrogram[Table[SawtoothWave[(( i)/100)+((((i/1000)))^2)],{i,10000}]]

Cepstrogram of an audio signal:

Cepstrogram[]

OpenersExampleSection1(Spacer1)Scope  (1)

By default, a suitable window size and offset are chosen:

a=;

Cepstrogram[a]

Specify the window size that corresponds to the quefrency range:

Cepstrogram[a,64]

Use a specific window size and offset:

Cepstrogram[a,64,32]

Use a larger window size to get a bigger quefrency range:

Cepstrogram[a,256,64]

Specify a smoothing window function:

Cepstrogram[a,256,64,HammingWindow]

No smoothing:

Cepstrogram[a,256,64,None]

OpenersExampleSection3(Spacer1)Applications  (2)

Detect the effect of a "flanger" (time-varying comb filter) in a recording:

a=;

The spectrogram is not very useful in showing the effect:

Spectrogram[a]

The cepstrogram allows a decoupling of the components from the signal and the flanger:

Cepstrogram[a]

Cepstrogram of an image:

i=;

Cepstrogram[Flatten[ImageData[i]],512,64,HannWindow]

OpenersExampleSection4(Spacer1)Properties & Relations  (2)

On multichannel (RefLink[Sound, paclet:ref/Sound]) or (RefLink[Audio, paclet:ref/Audio]), cepstrogram is computed on the sum of the channels:

a=;

AudioChannels[a]

Cepstrogram[a]===Cepstrogram@Total@AudioChannelSeparate[a]

Create a cepstrogram from the (RefLink[CepstrogramArray, paclet:ref/CepstrogramArray]):

chirp=Table[SawtoothWave[(( i)/100)+((((i/1000)))^2)],{i,10000}];
ca=CepstrogramArray[chirp];

ListDensityPlot[Transpose[Abs[ca]][[;;(Last@Dimensions[ca]/2)]],Frame->None,AspectRatio->1/3]

Comparison with the (RefLink[Cepstrogram, paclet:ref/Cepstrogram]) output:

Cepstrogram[chirp,Frame->False]

OpenersExampleSection5(Spacer1)Neat Examples  (1)

Look at the evolution of the reciprocal of the fundamental frequency:

a=ExampleData[{"Audio","Bee"},"Audio"]

Cepstrogram[a,2048,64,PlotRange->{All,{0,.008},All},AspectRatio->1/3,ColorFunction->(Blend[{{0,Black},{.2,White}},#]&)]

({{DocumentationFooterIconsRelatedFunction.png, ({{See Also}, {(RefLink[CepstrogramArray, paclet:ref/CepstrogramArray])  ▪  (RefLink[CepstrumArray, paclet:ref/CepstrumArray])  ▪  (RefLink[Spectrogram, paclet:ref/Spectrogram])  ▪  (RefLink[SpectrogramArray, paclet:ref/SpectrogramArray])  ▪  (RefLink[PeriodogramArray, paclet:ref/PeriodogramArray])  ▪  (RefLink[Periodogram, paclet:ref/Periodogram])}})}})

({{DocumentationFooterIconsRelatedGuide.png, ({{Related Guides}, {▪(RefLinkPlain[Fourier Analysis, paclet:guide/FourierAnalysis])}, {▪(RefLinkPlain[Signal Processing, paclet:guide/SignalProcessing])}, {▪(RefLinkPlain[Summation Transforms, paclet:guide/SummationTransforms])}, {▪(RefLinkPlain[Audio Representation, paclet:guide/AudioRepresentation])}, {▪(RefLinkPlain[Audio Processing, paclet:guide/AudioProcessing])}})}})