Reduksi Noise Dari Rekaman Suara Pernapasan Menggunakan Wavelet Transform Based Filter

(1)

1. Preprocess.java

public class Preprocess {

public static final int SAMPLE_RATE = 44100;

public static final double MAX_16_BIT = Short.MAX_VALUE;

/**

* Baca audio samples dari wav file dan kembalikan sebagai larik bertipe double

* dengan nilai antara -1.0 dan +1.0. *

* @return d */

public static double[] baca(String namafile) { byte[] data = bacaByte(namafile);

int N = data.length;

double[] d = new double[N/2]; for(int i=0; i<N/2; i++) {

d[i] = ((short) (((data[2*i+1] & 0xFF) << 8) + (data[2*i] &0xFF))) / ((double) MAX_16_BIT);

}

return d; }

/**

* Baca data dan kembalikan sebagai larik bertipe byte. *

* @return data */

private static byte[] bacaByte(String namafile) {

byte[] data = null;

AudioInputStream ais = null; try {

// Membaca file

File file = new File(namafile); if(file.exists()) {

ais = AudioSystem.getAudioInputStream(file);

data = new byte[ais.available()]; ais.read(data);

}

} catch (Exception ex) {

System.out.println(ex.getMessage());

throw new RuntimeException("Tidak dapat membaca " + namafile); }

return data; }

(2)

2. SignalFilter.java

public class SignalFilter {

/** Koefisien untuk menandakan wavelet transform dengan berapa koefisien yang dipakai. */

public static final int DB_NO = 4;

/** Koefisien pertama Wavelet Transform Based Filter. */ public static final double k0 = (1+sqrt(3))/(4*sqrt(2));

/** Koefisien kedua Wavelet Transform Based Filter. */ public static final double k1 = (3+sqrt(3))/(4*sqrt(2));

/** Koefisien ketiga Wavelet Transform Based Filter. */ public static final double k2 = (3-sqrt(3))/(4*sqrt(2));

/** Koefisien keempat Wavelet Transform Based Filter. */ public static final double k3 = (1-sqrt(3))/(4*sqrt(2));

/**

* Method decomposition melakukan dekomposisi sinyal input menjadi dua bagian

* yang masing-masing bagian memiliki panjang setengah dari panjang sinyal input.

* Bagian pertama disebut low pass filter, sedangkan bagian kedua disebut high pass filter.

* Bagian low pass filter dapat didekomposisi lagi menjadi 2 bagian seperti sebelumnya.

* Iterasi dekomposisi ini dilakukan sebanyak level yang ditentukan. *

* @param si sinyal input yang akan didekomposisi. * @param level jumlah dilakukannya dekomposisi.

* @return sinyal yang didekomposisi yang dibangun oleh bagian low pass filter dan high pass filter,

* panjangnya sama dengan sinyal input. */

public static double[] decomposition(double[] si, int level) { int lth = si.length;

// Panjang matriks yang didekomposisi di suatu level int currentLevelLength = lth;

double[] result = new double[lth];

// Lakukan proses dekomposisi sebanyak level for(int i = 0; i < level; i++) {

double[] tmp = result.clone(); int index = 0;

// Lakukan dekomposisi

for(int j = 0; j < currentLevelLength; j+=2) { tmp[j] = k0*si[index] + k1*si[index+1] +

k2*si[(index+2)%currentLevelLength] + k3*si[(index+3)%currentLevelLength];

tmp[j+1] = k3*si[index] - k2*si[index+1] +

(3)

index+=2; }

index = 0;

result = tmp.clone();

// Atur output agar bagian low pass filter di setengah depan output // dan bagian high pass filter di setengah belakang output

for(int j = 0; j < currentLevelLength/2; j+=1) { result[index] = tmp[2*j];

result[index+currentLevelLength/2] = tmp[2*j+1];

index+=1; }

currentLevelLength = currentLevelLength / 2; si = result;

}

return result; }

/**

* Method getvbs melakukan threshold terhadap sinyal input dan memisahkan * sinyal suara pernapasan dan noise.

*

* @param si

* @return sinyal suara pernapasan */

public static double[] getvbs(double[] si) { int lth = si.length;

double t, sum = 0, sum2 = 0;

double[] tmp1 = si.clone();

double[] vbs = new double[lth];

double[] vn = new double[lth];

int x = 0, y = 0;

for(int i = 0; i < lth; i++) { sum += tmp1[i];

}

double mean = sum / lth;

for(int i = 0; i < lth; i++) {

tmp3[i] = (tmp2[i] - mean) * (tmp2[i] - mean); }

(4)

sum2 += tmp3[i]; }

double sd = Math.sqrt(sum2/lth);

// Hitung threshold

t = sd * sqrt((2 * Math.log(lth)));

for(int j = 0; j < lth; j++) { if(Math.abs(si[j]) >= t) { vn[x] = si[j];

x++; } else {

vbs[y] = si[j]; y++;

} }

return vbs; }

/**

* Method getvn melakukan threshold terhadap sinyal input dan memisahkan * sinyal suara pernapasan dan noise.

*

* @param si * @return noise */

public static double[] getvn(double[] si) { int lth = si.length;

double t, sum = 0, sum2 = 0;

double[] vbs = new double[lth];

double[] vn = new double[lth];

int x = 0, y = 0;

for(int i = 0; i < lth; i++) { sum += tmp1[i];

}

double mean = sum / lth;

for(int i = 0; i < lth; i++) {

tmp3[i] = (tmp2[i] - mean) * (tmp2[i] - mean); }

for(int i = 0; i < lth; i++) { sum2 += tmp3[i];

(5)

double sd = Math.sqrt(sum2/lth);

// Hitung threshold

t = sd * sqrt((2 * Math.log(lth)));

for(int j = 0; j < lth; j++) { if(Math.abs(si[j]) >= t) { vn[x] = si[j];

x++; } else {

vbs[y] = si[j]; y++;

} }

return vn; }

/**

* Method reconstruction melakukan rekonstruksi sinyal suara pernapasan * dan noise dari tahap threshold.

*

* @param si sinyal input yang akan direkonstruksi. * @param level jumlah dilakukannya rekonstruksi. * @return sinyal yang telah direkonstruksi. */

public static double[] reconstrution(double[] si, int level) { int lth = si.length;

int currentLevelLength = lth / (int)Math.pow(2, level-1);

double[] result = si.clone();

// Lakukan proses rekonstruksi sebanyak level for(int i = 0; i < level; i++) {

int index = 0;

double[] tmp = result.clone();

// Ubah urutan sinyal dari sebelumnya terbagi dua,

// setengah low pass filter dan setengah high pass filter, menjadi // selang-seling low pass filter - high pass filter

for(int j = 0; j < currentLevelLength; j+=2) { tmp[j] = result[index];

tmp[j+1] = result[index+currentLevelLength/2]; index+=1;

}

index = currentLevelLength-2; result = tmp.clone();

// Lakukan proses rekonstruksi

for(int j = 0; j < currentLevelLength; j+=2) {

result[j] = k2*tmp[index] + k1*tmp[index+1] +

k0*tmp[(index+2)%currentLevelLength] +

k3*tmp[(index+3)%currentLevelLength];

result[j+1] = k3*tmp[index] - k0*tmp[index+1] +

k1*tmp[(index+2)%currentLevelLength] -

(6)

index = (index + 2)%currentLevelLength; }

currentLevelLength = currentLevelLength * 2; }

return result; }

}

3. Finalprocess.java

public class Finalprocess {

public static final int SAMPLE_RATE = 44100;

public static final double MAX_16_BIT = Short.MAX_VALUE;

/**

* Simpan larik bertipe double sebagai file sound. */

public static void simpan(String namafile, double[] input) {

// 44,100 samples per second

// Gunakan 16-bit audio, mono, signed PCM, little Endian

AudioFormat format = new AudioFormat(SAMPLE_RATE, 16, 1, true,

false);

byte[] data = new byte[2 * input.length];

for (int i = 0; i < input.length; i++) {

int temp = (short) (input[i] * MAX_16_BIT);

data[2*i + 0] = (byte) temp;

data[2*i + 1] = (byte) (temp >> 8); }

// Simpan file try {

ByteArrayInputStream bais = new ByteArrayInputStream(data); AudioInputStream ais = new AudioInputStream(bais, format, input.length);

if (namafile.endsWith(".wav") || namafile.endsWith(".WAV")) {

AudioSystem.write(ais, AudioFileFormat.Type.WAVE, new

File(namafile)); } else {

throw new RuntimeException("File format tidak dapat

digunakan: " + namafile); }

}

catch (Exception e) {

System.out.println(e);

System.exit(1);

(7)

4. MainWindow.java

public class MainWindow extends JFrame implements ActionListener {

/**

* Aplikasi dijalankan. * @param args

*/

public static void main(String[] args) {

EventQueue.invokeLater(new Runnable() {

@Override

public void run() { new MainWindow(); }

}); }

public MainWindow() {

frmMain.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

series1 = new XYSeries("Signal");

series2 = new XYSeries("Signal");

dataset1 = new XYSeriesCollection(series1);

dataset2 = new XYSeriesCollection(series2);

waveform1 = createWaveform(title1, dataset1); waveform2 = createWaveform(title2, dataset2);

cpWaveform1 = new ChartPanel(waveform1);

cpWaveform1.setPreferredSize(new java.awt.Dimension(700, 200));

cpWaveform2 = new ChartPanel(waveform2);

cpWaveform2.setPreferredSize(new java.awt.Dimension(700, 200));

btnOpen = addButton("Open", tbButtons, true);

btnPlay = addButton("Play", tbButtons, false);

btnPause = addButton("Pause", tbButtons, false);

btnDenoise = addButton("Denoise", tbButtons, false);

btnCalculateSNR = addButton("Calculate SNR", tbButtons, false);

btnCleanCanvas = addButton("Clean Canvas", tbButtons, true);

tbButtons.setFloatable(false);

tbButtons.setBackground(Color.WHITE);

tbButtons.add(btnOpen);

tbButtons.add(btnPlay);

tbButtons.add(btnPause);

tbButtons.add(btnDenoise);

tbButtons.add(btnCalculateSNR);

tbButtons.add(btnCleanCanvas);

lblFile.setHorizontalAlignment(JLabel.LEFT);

spnCalculation = new JScrollPane();

gbc_scrollPane = new GridBagConstraints();

gbc_scrollPane.fill = GridBagConstraints.BOTH;

gbc_scrollPane.gridx = 0;

(8)

txtCalculation.setLineWrap(true);

txtCalculation.setFont(new Font("Arial", Font.PLAIN, 12));

txtCalculation.setColumns(50);

txtCalculation.setRows(5);

spnCalculation.setViewportView(txtCalculation);

spnCalculation.setBorder(eBorder);

pnlCalculation.add(spnCalculation, gbc_scrollPane);

pnlCalculation.setBackground(Color.WHITE);

pnlMiddle2.add(lblFile);

pnlMiddle2.setBackground(Color.WHITE);

pnlMiddle3.add(tbButtons);

pnlMiddle4.add(lblCalculation);

pnlSub.setLayout(new BoxLayout(pnlSub, BoxLayout.Y_AXIS));

pnlSub.add(cpWaveform1);

pnlSub.add(cpWaveform2);

pnlSub.add(pnlMiddle2);

pnlSub.add(pnlCalculation);

pnlContent.add(pnlSub);

frmMain.setContentPane(pnlContent);

frmMain.pack();

frmMain.setResizable(false);

frmMain.setLocationRelativeTo(getLayeredPane());

frmMain.setVisible(true); }

private JFreeChart createWaveform(String title, XYDataset dataset) { JFreeChart jfreechart = ChartFactory.createXYLineChart(title, "Waktu",

"Amplitudo", dataset, PlotOrientation.VERTICAL, false, false, false);

jfreechart.setBackgroundPaint(Color.WHITE);

XYPlot xyplot = (XYPlot) jfreechart.getPlot();

xyplot.setBackgroundPaint(Color.lightGray);

xyplot.setDomainGridlinePaint(Color.WHITE);

xyplot.setRangeGridlinePaint(Color.WHITE);

return jfreechart; }

private JButton addButton(String name, JToolBar jtb, boolean state) { // TODO Auto-generated method stub

JButton b = new JButton(name); b.addActionListener(this); b.setEnabled(state); jtb.add(b);

return b; }

@Override

public void actionPerformed(ActionEvent ae) { // TODO Auto-generated method stub

(9)

if(obj.equals(btnOpen)) {

player.stop();

loader.start();

btnPlay.setEnabled(false);

btnPause.setEnabled(false);

btnDenoise.setEnabled(false);

btnCalculateSNR.setEnabled(false);

} else if(obj.equals(btnPlay)) {

if(btnPlay.getText().startsWith("Play")) {

player.start();

btnPause.setEnabled(true);

btnPlay.setText("Stop"); } else {

player.stop();

btnPlay.setText("Play"); }

} else if(obj.equals(btnPause)) {

if(btnPause.getText().startsWith("Pause")) { if(player.trdPlayer != null) {

player.sdLine.stop(); }

btnPause.setText("Resume"); } else {

if(player.trdPlayer != null) {

player.sdLine.start(); }

btnPause.setText("Pause"); }

} else if(obj.equals(btnDenoise)) {

denoise.start();

} else if(obj.equals(btnCalculateSNR)) {

ratio.start();

} else if(obj.equals(btnCleanCanvas)) {

player.stop();

cleaner.start(); }

}

/**

* Loader class. Pengaturan membuka fie audio dan menggambar waveform. * @author Samuel Situmeang

* */

public class Loader implements Runnable { private Thread trdLoader;

public void start() {

trdLoader = new Thread(this);

trdLoader.setName("Loader");

trdLoader.start(); }

(10)

if(trdLoader != null) {

trdLoader.interrupt(); }

trdLoader = null; }

public void run() {

fc.setCurrentDirectory(new File(System.getProperty("user.dir"))); int a = fc.showOpenDialog(null);

if(a == JFileChooser.APPROVE_OPTION) { try {

url = fc.getSelectedFile().getPath();

File urlFile = new File(url);

String filename = urlFile.getName();

lblFile.setText(filename);

double[] signal = Preprocess.baca(url);

for (int i = 0; i < signal.length; i+=50) { double x = i;

double y = signal[i];

series1.addOrUpdate(x, y);

}

} catch(Exception ex) {

JOptionPane.showMessageDialog(null, "File tidak dapat dibuka.","Pesan",JOptionPane.ERROR_MESSAGE);

lblFile.setText(""); }

btnPlay.setEnabled(true);

btnDenoise.setEnabled(true); } else {

btnDenoise.setEnabled(false); }

} }

/**

* Player class. Pengaturan memainkan file audio. * @author Samuel Situmeang

* */

public class Player implements Runnable { private SourceDataLine sdLine;

private Thread trdPlayer;

errStr = null;

trdPlayer = new Thread(this);

trdPlayer.setName("Player");

trdPlayer.start(); }

public void stop() {

trdPlayer = null; }

private void shutDown(String message) { if((errStr = message) != null) {

(11)

cpWaveform1.repaint();

cpWaveform2.repaint(); }

if(trdPlayer != null) {

trdPlayer = null;

btnPlay.setText("Play"); }

}

public void run() { try {

audioFile = new File(url); } catch(Exception ex) { ex.printStackTrace(); System.exit(1); }

try {

audioInputStream = AudioSystem.getAudioInputStream(audioFile); } catch(Exception ex) {

ex.printStackTrace(); System.exit(1); }

audioFormat = audioInputStream.getFormat();

DataLine.Info info = new DataLine.Info(SourceDataLine.class, audioFormat);

try {

sdLine = (SourceDataLine) AudioSystem.getLine(info);

sdLine.open(audioFormat);

} catch(LineUnavailableException lue) { lue.printStackTrace();

System.exit(1);

} catch(Exception ex) { ex.printStackTrace(); System.exit(1); }

int frameSizeInBytes = audioFormat.getFrameSize(); int bufferLengthInFrames = sdLine.getBufferSize() / 8;

int bufferLengthInBytes = bufferLengthInFrames * frameSizeInBytes; int nBytesRead = 0;

byte[] abData = new byte[bufferLengthInBytes];

sdLine.start();

while(trdPlayer != null) { try {

if((nBytesRead = audioInputStream.read(abData)) == -1) { break;

}

int nBytesRemaining = nBytesRead; while (nBytesRemaining > 0) {

nBytesRemaining -= sdLine.write(abData, 0, nBytesRemaining);

}

(12)

shutDown("Error sewaktu dimainkan: " + ex); break;

} }

if(trdPlayer != null) {

sdLine.drain(); }

sdLine.stop();

sdLine.close();

sdLine = null; shutDown(null); }

}

/**

* Denoise class. Pengaturan denoise file rekaman suara pernapasan. * @author Samuel Situmeang

* */

public class Denoise implements Runnable { private Thread trdDenoise;

trdDenoise = new Thread(this);

trdDenoise.setName("Denoise");

trdDenoise.start(); }

public void stop() { if(trdDenoise != null) {

trdDenoise.interrupt(); }

trdDenoise = null; }

double[] sinyalAudio = Preprocess.baca(url);

//PrintArray.print(sinyalAudio, "sinyalAudio.txt");

double[] dekomposisiSinyalAudio = SignalFilter.decomposition(sinyalAudio, 2);

//PrintArray.print(dekomposisiSinyalAudio, "dekomposisiSinyalAudio.txt");

double[] breathSignal = SignalFilter.getvbs(dekomposisiSinyalAudio); //PrintArray.print(breathSignal, "breathSignal.txt");

double[] noise = SignalFilter.getvn(dekomposisiSinyalAudio); //PrintArray.print(noise, "noise.txt");

double[] rekonstruksiSinyalAudio = SignalFilter.reconstrution(breathSignal, 2);

//PrintArray.print(rekonstruksiSinyalAudio, "rekonstruksiSinyalAudio.txt");

(13)

Finalprocess.simpan("src/Reducted.wav", rekonstruksiSinyalAudio);

Finalprocess.simpan("src/Noise.wav", rekonstruksiNoise);

double[] signal = Preprocess.baca("src/Reducted.wav"); for (int i = 0; i < signal.length; i+=50) { double x = i;

double y = signal[i];

series2.addOrUpdate(x, y);

}

btnCalculateSNR.setEnabled(true); }

}

/**

* Ratio class. Pengaturan perhitungan nilai Signal to Noise Ratio (SNR). * @author Samuel Situmeang

* */

public class Ratio implements Runnable { private Thread trdRatio;

trdRatio = new Thread(this);

trdRatio.setName("Ratio");

trdRatio.start(); }

public void stop() { if(trdRatio != null) {

trdRatio.interrupt(); }

trdRatio = null; }

double[] signalReducted = Preprocess.baca("src/Reducted.wav"); double[] signalNoise = Preprocess.baca("src/Noise.wav");;

double xisr = 1; double xrmssr = 1; double xisn = 1; double xrmssn = 1; double snr = 1.0; double snr_db = 1.0; int size = 0;

// Tentukan Root Mean Square Amplitude Sinyal Tereduksi for(int i = 0; i < signalReducted.length; i++) {

signalReducted[i] = signalReducted[i]*signalReducted[i]; xisr += signalReducted[i];

}

xrmssr = xisr/(signalReducted.length);

// Tentukan Root Mean Square Amplitude Noise for(int i = 0; i < size; i++) {

(14)

xisn += signalNoise[i]; }

xrmssn = xisn/(signalNoise.length);

snr = (xrmssr/xrmssn) * (xrmssr/xrmssn);

snr_db = 10 * Math.log10(snr);

txtCalculation.setText("Signal-to-noise ratio : " + FormatDesimal.twoDF(snr) + "\n"

+ "Signal-to-noise ratio_db : " + FormatDesimal.twoDF(snr_db) + " dB"); }

}

/**

* Cleaner class. Pengaturan membersihkan panel dari gambar sinyal. * @author Samuel Situmeang

* */

public class Cleaner implements Runnable { private Thread trdCleaner;

trdCleaner = new Thread(this);

trdCleaner.setName("Printer");

trdCleaner.start(); }

public void stop() { if(trdCleaner != null) {

trdCleaner.interrupt(); }

trdCleaner = null; }

series1.clear();

series2.clear();

lblFile.setText("No file Label");

txtCalculation.setText(null);

btnPause.setEnabled(false); }