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Fix up octave data reduction
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Issue #332 Now that have ability to visualise a data reduced spectrogram, I changed it to give better distribution of filterbanks.
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@towsey
towsey committed Aug 20, 2020
1 parent 6acfa88 commit 13968a3
Showing 1 changed file with 25 additions and 24 deletions.
49 changes: 25 additions & 24 deletions tests/Acoustics.Test/AudioAnalysisTools/DSP/FrequencyScaleTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -7,15 +7,14 @@ namespace Acoustics.Test.AudioAnalysisTools.DSP
using System;
using System.Collections.Generic;
using System.IO;
using Acoustics.Shared;
using Acoustics.Test.TestHelpers;
using global::AudioAnalysisTools.DSP;
using global::AudioAnalysisTools.StandardSpectrograms;
using global::AudioAnalysisTools.WavTools;
using global::TowseyLibrary;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using SixLabors.ImageSharp;
using static global::TowseyLibrary.FFT;
//using static global::TowseyLibrary.FFT;
using Path = System.IO.Path;

/// <summary>
Expand Down Expand Up @@ -332,27 +331,27 @@ public void TestReturnOfBinIndex()
// test contents of the octave bin bounds matrix.
int[,] octaveBinBounds = freqScale.BinBounds;

Assert.AreEqual(20, octaveBinBounds.GetLength(0));
Assert.AreEqual(19, octaveBinBounds.GetLength(0));

int hertzValue = 500;
var binId = freqScale.GetBinIdForHerzValue(hertzValue);
Assert.AreEqual(2, binId);

hertzValue = 1000;
binId = freqScale.GetBinIdForHerzValue(hertzValue);
Assert.AreEqual(4, binId);
Assert.AreEqual(3, binId);

hertzValue = 2000;
binId = freqScale.GetBinIdForHerzValue(hertzValue);
Assert.AreEqual(7, binId);
Assert.AreEqual(6, binId);

hertzValue = 4000;
binId = freqScale.GetBinIdForHerzValue(hertzValue);
Assert.AreEqual(12, binId);
Assert.AreEqual(11, binId);

hertzValue = 8000;
binId = freqScale.GetBinIdForHerzValue(hertzValue);
Assert.AreEqual(17, binId);
Assert.AreEqual(16, binId);
}

/// <summary>
Expand Down Expand Up @@ -400,7 +399,7 @@ public void TestSplitLinearOctaveFrequencyScale()
linearSpectrum[128] = 1.0;
linearSpectrum[255] = 1.0;

double[] octaveSpectrum = OctaveFreqScale.ConvertLinearSpectrumToOctaveScale(octaveBinBounds, linearSpectrum);
double[] octaveSpectrum = SpectrogramTools.RescaleSpectrumUsingFilterbank(octaveBinBounds, linearSpectrum);

Assert.AreEqual(103, octaveSpectrum.Length);
Assert.AreEqual(1.0, octaveSpectrum[0]);
Expand Down Expand Up @@ -440,7 +439,7 @@ public void TestConversionOfAmplitudeSpectrogramToOctaveScaled()
linearSpectrum[192] = 1.0;
linearSpectrum[255] = 1.0;

var octaveSpectrum = OctaveFreqScale.ConvertLinearSpectrumToOctaveScale(freqScale.BinBounds, linearSpectrum);
var octaveSpectrum = SpectrogramTools.RescaleSpectrumUsingFilterbank(freqScale.BinBounds, linearSpectrum);
Assert.AreEqual(1.000, octaveSpectrum[0], 0.0001);
Assert.AreEqual(0.000, octaveSpectrum[1], 0.0001);
Assert.AreEqual(0.000, octaveSpectrum[55], 0.0001);
Expand Down Expand Up @@ -805,13 +804,15 @@ public void TestSpectralReductionScale()
Assert.AreEqual(freqScale.ScaleType, FreqScaleType.OctaveDataReduction);

// test contents of the octave bin bounds matrix.
Assert.AreEqual(20, freqScale.BinBounds.GetLength(0));
Assert.AreEqual(19, freqScale.BinBounds.GetLength(0));

var expectedBinBounds = new[,]
{
{ 0, 0 }, { 1, 258 }, { 2, 517 }, { 3, 775 }, { 4, 1034 }, { 5, 1292 }, { 6, 1550 }, { 47, 2024 },
{ 54, 2326 }, { 62, 2670 }, { 71, 3058 }, { 81, 3488 }, { 93, 4005 }, { 107, 4608 }, { 123, 5297 }, { 141, 6072 },
{ 162, 6977 }, { 186, 8010 }, { 214, 9216 }, { 255, 10982 },
{ 0, 0 }, { 8, 345 }, { 16, 689 }, // linear up to 1000 Hz
{ 24, 1034 }, { 32, 1378 }, { 40, 1723 }, // linear 1000-2000 Hz
{ 48, 2067 }, { 54, 2326 }, { 62, 2670 }, { 71, 3058 }, { 81, 3488 }, // first octave 2-4 kHz
{ 93, 4005 }, { 107, 4608 }, { 123, 5297 }, { 141, 6072 }, { 162, 6977 }, // second octave 4-8 kHz
{ 186, 8010 }, { 214, 9216 }, { 255, 10982 }, // residual octave 8-11 kHz
};

Assert.That.MatricesAreEqual(expectedBinBounds, freqScale.BinBounds);
Expand All @@ -822,17 +823,17 @@ public void TestSpectralReductionScale()
linearSpectrum[128] = 1.0;
linearSpectrum[255] = 1.0;

double[] octaveSpectrum = OctaveFreqScale.ConvertLinearSpectrumToOctaveScale(freqScale.BinBounds, linearSpectrum);

Assert.AreEqual(20, octaveSpectrum.Length);
Assert.AreEqual(1.0, octaveSpectrum[0]);
Assert.AreEqual(0.0, octaveSpectrum[1]);
Assert.AreEqual(0.0, octaveSpectrum[13]);
Assert.AreEqual(0.042483660130718942, octaveSpectrum[14]);
Assert.AreEqual(0.014245014245014251, octaveSpectrum[15]);
Assert.AreEqual(0.0, octaveSpectrum[16]);
Assert.AreEqual(0.0, octaveSpectrum[18]);
Assert.AreEqual(0.047619047619047616, octaveSpectrum[19], 0.000001);
double[] octaveSpectrum = SpectrogramTools.RescaleSpectrumUsingFilterbank(freqScale.BinBounds, linearSpectrum);

Assert.AreEqual(19, octaveSpectrum.Length);
Assert.AreEqual(0.222222, octaveSpectrum[0], 0.00001);
Assert.AreEqual(0.0, octaveSpectrum[1], 0.00001);
Assert.AreEqual(0.0, octaveSpectrum[12], 0.00001);
Assert.AreEqual(0.042483, octaveSpectrum[13], 0.00001);
Assert.AreEqual(0.014245, octaveSpectrum[14], 0.00001);
Assert.AreEqual(0.0, octaveSpectrum[15]);
Assert.AreEqual(0.0, octaveSpectrum[17]);
Assert.AreEqual(0.047619, octaveSpectrum[18], 0.00001);
}

/// <summary>
Expand Down

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