SpectralContrast Class Reference

Calculates the peak and valleys of the spectral contrast feature. More...

#include <SpectralContrast.h>

Inheritance diagram for SpectralContrast:

Protected Attributes
float	alpha
int	numBands
float *	bandHighFreq

Detailed Description

Calculates the peak and valleys of the spectral contrast feature.

Outputs

Valleys

The valley of each frequency sub-band

Peaks

The peak of each frequency sub-band

Mean

The mean of each frequency sub-band

Parameters

Alpha

Ratio of FFT bins used to find the peak/valley in each sub-band (default = 0.02)

Sub-bands

The number of sub-bands to use. (default = 7)

Description

This simple algorithm, taken from [1], divides a signal into N sub-bands and sorts the FFT bins in each sub-band by magnitude. The peak and valley are found by taking a proportion (defined as alpha) of FFT bins from the top/bottom of the sorted bins and finding the mean of those. The mean of all the FFT bins in each sub-band are also calculated. The 'spectral contrast' can be found by subtracting the valley from the peak in each sub-band, although this isn't calculated in the plugin.

[1] Jiang, D.-N., Lu, L., & Zhang, H.-J. (2002). Music type classification by spectral contrast feature. IEEE International Conference on Multimedia and Expo (pp. 113–116).

Thanks to Erik Schmidt at Drexel for providing a reference MATLAB implementation.

Member Data Documentation

alpha

float SpectralContrast::alpha

protected

Alpha parameter of spectral contrast algorithm

bandHighFreq

float* SpectralContrast::bandHighFreq

protected

Upper frequency range of each sub-band

numBands

int SpectralContrast::numBands

protected

Number of sub-bands to use

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The documentation for this class was generated from the following file:

• SpectralContrast.h