org.openimaj.audio.filters

Class TriangularFilter

java.lang.Object

org.openimaj.audio.filters.TriangularFilter

Direct Known Subclasses:

MelFilter

public class TriangularFilter
extends Object

A default non-isoceles triangular filter definition, where the low, mid and top frequencies are defined.

Version:

$Author$, $Revision$, $Date$

Author:

David Dupplaw (dpd@ecs.soton.ac.uk)

Created:

13 Dec 2012

Field Summary

Fields

Modifier and Type	Field and Description
protected double	centreFrequency The centre (peak) frequency of the filter
protected double	filterAmplitude The height of the filter
protected double	highFrequency The highest frequency of the filter
protected double	highSlope The slope of the second half of the filter
protected double	lowFrequency The lowest frequency of the filter
protected double	lowSlope The slope of first half of the filter.

Constructor Summary

Constructors

Constructor and Description
TriangularFilter(double low, double centre, double high)

Method Summary

Modifier and Type	Method and Description
double	getCentreFrequency() Get the centre frequency
double	getFilterAmplitude() Returns the filter amplitude
double	getHighFrequency() Gets the high frequency
double	getLowFrequency() Returns the lowest frequency of the filter
double[]	getResponseCurve(int nSpectrumBins, double maxFreq) Returns a set of values that represent the response of this filter when the linear frequency is split in the given number of bins.
double	getWeightAt(double frequency) Returns the weighting provided by this filter at the given frequency (Hz).
double	process(float[] frequencySpectrum, AudioFormat format) Requires a power spectrum and produces an output the filter
void	setCentreFrequency(double centreFrequency) Set the new centre frequency
void	setFilterAmplitude(double fa) Set the filter amplitude
void	setHighFrequency(double highFrequency) Set the high frequency of the filter
void	setLowFrequency(double lowFrequency) Sets the low frequency
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

lowFrequency

protected double lowFrequency

The lowest frequency of the filter

highFrequency

protected double highFrequency

The highest frequency of the filter

centreFrequency

protected double centreFrequency

The centre (peak) frequency of the filter

filterAmplitude

protected double filterAmplitude

The height of the filter

lowSlope

protected double lowSlope

The slope of first half of the filter.

highSlope

protected double highSlope

The slope of the second half of the filter

Constructor Detail

TriangularFilter

public TriangularFilter(double low,
                        double centre,
                        double high)

Parameters:

low -

centre -

high -

Method Detail

getLowFrequency

public double getLowFrequency()

Returns the lowest frequency of the filter

Returns:

The low frequency of the filter

setLowFrequency

public void setLowFrequency(double lowFrequency)

Sets the low frequency

Parameters:

lowFrequency - The new low frequency

getHighFrequency

public double getHighFrequency()

Gets the high frequency

Returns:

The high frequency

setHighFrequency

public void setHighFrequency(double highFrequency)

Set the high frequency of the filter

Parameters:

highFrequency - The new high frequency

getCentreFrequency

public double getCentreFrequency()

Get the centre frequency

Returns:

The centre frequency

setCentreFrequency

public void setCentreFrequency(double centreFrequency)

Set the new centre frequency

Parameters:

centreFrequency - The new centre frequency

process

public double process(float[] frequencySpectrum,
                      AudioFormat format)

Requires a power spectrum and produces an output the filter

Parameters:

frequencySpectrum - The power spectrum

format - The format of the samples used to create the spectrum

Returns:

The output power for the filter

getResponseCurve

public double[] getResponseCurve(int nSpectrumBins,
                                 double maxFreq)

Returns a set of values that represent the response of this filter when the linear frequency is split in the given number of bins. The result will have nSpectrumBins length.

Parameters:

nSpectrumBins - The number of bins in a spectrum.

maxFreq - The maximum frequency (sample rate)

Returns:

The response curve.

getWeightAt

public double getWeightAt(double frequency)

Returns the weighting provided by this filter at the given frequency (Hz).

Parameters:

frequency - The frequency (Hz) to get the weight for

Returns:

The weight at the given frequency (Hz) for this filter

getFilterAmplitude

public double getFilterAmplitude()

Returns the filter amplitude

Returns:

The filter amplitude

setFilterAmplitude

public void setFilterAmplitude(double fa)

Set the filter amplitude

Parameters:

fa - The filter amplitude

toString

public String toString()

Overrides:

toString in class Object

See Also:

Object.toString()