Cepstrogram

Cepstrogram[data]

plots the array of power cepstra computed on each partition of data.

Cepstrogram[data,n]

uses partitions of length n.

Cepstrogram[data,n,d]

uses partitions with offset d.

Cepstrogram[data,n,d,wfun]

applies a smoothing window wfun to each partition.

Cepstrogram[data,n,d,wfun,m]

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

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 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.
Cepstrogram[list] uses partitions of length and offset , where m is Length[list].
In Cepstrogram[list,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.
The data can be any of the following:
list 1D numerical array

audio an Audio or Sound object
For multichannel audio objects, the cepstrogram is computed over the sum of all channels.
Cepstrogram accepts all Graphics options with the following additions and changes:

AspectRatio	1/3	ratio of height to width
ClippingStyle	None	how to show cells whose values are clipped
ColorFunction	Automatic	how each cell should be colored
ColorFunctionScaling	True	whether to scale the argument to ColorFunction
ColorRules	Automatic	rules for determining colors from values
DataRange	Automatic	the range of and values to assume
DataReversed	False	whether to reverse the order of rows
FourierParameters	{1,-1}	Fourier parameters
Frame	Automatic	whether to draw a frame around the plot
MaxPlotPoints	∞	the maximum number of points to include
Mesh	False	whether to draw a mesh
MeshStyle	GrayLevel[-1+GoldenRatio]	the style to use for a mesh
Padding	Automatic	padding scheme
PaddingSize	{0,0}	amount of padding
PixelConstrained	False	how to constrain cells to align with pixels
PlotLegends	None	legends for datasets

Examples

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Basic Examples (2)

Cepstrogram of a sawtooth chirp signal:

Cepstrogram of an audio signal:

Scope (1)

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

Specify the window size that corresponds to the quefrency range:

Use a specific window size and offset:

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

Specify a smoothing window function:

No smoothing:

Applications (2)

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

The spectrogram is not very useful in showing the effect:

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

Cepstrogram of an image:

Properties & Relations (2)

On multichannel Sound or Audio, cepstrogram is computed on the sum of the channels:

Create a cepstrogram from the CepstrogramArray:

Comparison with the Cepstrogram output:

Neat Examples (1)

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

Introduced in 2017

(11.1)

Updated in 2017

(11.2)

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	list	1D numerical array
	audio	an Audio or Sound object