public void TestPcaWhitening()
{
var recordingPath = PathHelper.ResolveAsset("Recordings", "BAC2_20071008-085040.wav");
var outputDir = this.outputDirectory;
var outputImagePath = Path.Combine(outputDir.FullName, "ReconstrcutedSpectrogram.png");
var fst = FreqScaleType.Linear;
var freqScale = new FrequencyScale(fst);
var recording = new AudioRecording(recordingPath);
var sonoConfig = new SonogramConfig
{
WindowSize = freqScale.FinalBinCount * 2,
WindowOverlap = 0.2,
SourceFName = recording.BaseName,
NoiseReductionType = NoiseReductionType.None,
NoiseReductionParameter = 0.0,
};
// GENERATE AMPLITUDE SPECTROGRAM
var spectrogram = new AmplitudeSonogram(sonoConfig, recording.WavReader);
spectrogram.Configuration.WindowSize = freqScale.WindowSize;
// DO RMS NORMALIZATION
spectrogram.Data = SNR.RmsNormalization(spectrogram.Data);
// CONVERT NORMALIZED AMPLITUDE SPECTROGRAM TO dB SPECTROGRAM
var sonogram = new SpectrogramStandard(spectrogram);
// DO NOISE REDUCTION
var dataMatrix = PcaWhitening.NoiseReduction(sonogram.Data);
sonogram.Data = dataMatrix;
// Do Patch Sampling
int rows = sonogram.Data.GetLength(0);
int columns = sonogram.Data.GetLength(1);
int patchWidth = columns;
int patchHeight = 1;
int numberOfPatches = (rows / patchHeight) * (columns / patchWidth);
var sequentialPatches = PatchSampling.GetPatches(sonogram.Data, patchWidth, patchHeight, numberOfPatches, PatchSampling.SamplingMethod.Sequential);
double[,] sequentialPatchMatrix = sequentialPatches.ToMatrix();
// DO PCA WHITENING
var whitenedSpectrogram = PcaWhitening.Whitening(sequentialPatchMatrix);
// reconstructing the spectrogram from sequential patches and the projection matrix obtained from random patches
var projectionMatrix = whitenedSpectrogram.ProjectionMatrix;//whitenedSpectrogram.projectionMatrix;
var eigenVectors = whitenedSpectrogram.EigenVectors;
var numComponents = whitenedSpectrogram.Components;
double[,] reconstructedSpec = PcaWhitening.ReconstructSpectrogram(projectionMatrix, sequentialPatchMatrix, eigenVectors, numComponents);
sonogram.Data = PatchSampling.ConvertPatches(reconstructedSpec, patchWidth, patchHeight, columns);
var reconstructedSpecImage = sonogram.GetImageFullyAnnotated(sonogram.GetImage(), "RECONSTRUCTEDSPECTROGRAM: " + fst.ToString(), freqScale.GridLineLocations);
reconstructedSpecImage.Save(outputImagePath, ImageFormat.Png);
// DO UNIT TESTING
Assert.AreEqual(spectrogram.Data.GetLength(0), sonogram.Data.GetLength(0));
Assert.AreEqual(spectrogram.Data.GetLength(1), sonogram.Data.GetLength(1));
}
