title: Exception in thread "AWT-EventQueue-0"
body: <p>I am currently doing a project on steganography using discrete Wavelet Transform.I have already written the code and compiled it.However I am facing some exceptions.Kindly help me interpret the exceptions.
  The exception is as follows</p>
  
  <pre><code>        Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: null
          at java.lang.Integer.parseInt(Unknown Source)
          at java.lang.Integer.parseInt(Unknown Source)
          at DWT.dwtFunc(Steganography.java:292)
          at TextInput.actionPerformed(Steganography.java:252)
          at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
          at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
          at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
          at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
          at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
          at java.awt.Component.processMouseEvent(Unknown Source)
          at javax.swing.JComponent.processMouseEvent(Unknown Source)
          at java.awt.Component.processEvent(Unknown Source)
          at java.awt.Container.processEvent(Unknown Source)
          at java.awt.Component.dispatchEventImpl(Unknown Source)
          at java.awt.Container.dispatchEventImpl(Unknown Source)
          at java.awt.Component.dispatchEvent(Unknown Source)
          at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
          at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
          at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
          at java.awt.Container.dispatchEventImpl(Unknown Source)
          at java.awt.Window.dispatchEventImpl(Unknown Source)
          at java.awt.Component.dispatchEvent(Unknown Source)
          at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
          at java.awt.EventQueue.access$000(Unknown Source)
          at java.awt.EventQueue$1.run(Unknown Source)
          at java.awt.EventQueue$1.run(Unknown Source)
          at java.security.AccessController.doPrivileged(Native Method)
          at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
          at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
          at java.awt.EventQueue$2.run(Unknown Source)
          at java.awt.EventQueue$2.run(Unknown Source)
          at java.security.AccessController.doPrivileged(Native Method)
          at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
          at java.awt.EventQueue.dispatchEvent(Unknown Source)
          at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
          at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
          at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
          at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
          at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
          at java.awt.EventDispatchThread.run(Unknown Source)
  </code></pre>
  
  <p>I am new in Stack Overflow.Forgive me if I have made any mistake while posting the question.
  Thank You</p>
  
  <p>Re:
  Sorry Sir I am still getting acquainted to the rules of the forum.</p>
  
  <p>The code for detection of skin region in an image is</p>
  
  <pre><code>    import java.awt.event.*;
      import javax.swing.*;
      import java.awt.image.BufferedImage;
      import javax.swing.JFrame;
      import javax.swing.SwingUtilities;
      import java.io.*;
      import javax.swing.JFileChooser;
      import javax.swing.filechooser.FileFilter;
      import javax.swing.filechooser.FileNameExtensionFilter;
      import javax.imageio.ImageIO;
      import java.awt.*;
      import java.lang.*;
  
      public class demo2
      {
  
          public void skindet()
          {
              float[] hsvval;
              float hue,sat,val;
              int counter = 0;
              String[] skinpixel = new String[200000];
              int scount = 0;
              try
              {
  
                  BufferedImage image = ImageIO.read(new File("lena.png"));
                  int[][] rgb=new int[550][550];
                  int w = image.getWidth();
                  int h = image.getHeight();
                  hsvval=new float[3];
                  int red,green,blue;
                  for (int i=0;i&lt;w;i++) 
                  {
                      for (int j=0;j&lt;h;j++)
                      {
                          rgb[i][j] =image.getRGB(i,j);
                          red=(rgb[i][j] &gt;&gt; 16) &amp; 0xff;
                          green=(rgb[i][j] &gt;&gt; 8) &amp; 0xff;
                          blue=(rgb[i][j]) &amp; 0xff;
                          float[] values = Color.RGBtoHSB(red,green,blue,null);
                          for(int s=0;s&lt;3;s++)
                          {
                              hsvval[counter]=values[s];
                              counter++;
                          }
                          hue=hsvval[0];
                          sat=hsvval[1];
                          val=hsvval[2];
                          if(hue&gt;0 &amp;&amp; hue&lt;0.11 &amp;&amp; sat&gt;0.2 &amp;&amp; sat&lt;0.7)
                          {
                              String xcor=Integer.toString(i);
                              String ycor=Integer.toString(j);
                              skinpixel[scount]=xcor;
                              scount++;
                              skinpixel[scount]=ycor;
                              scount++;
                          }
                      }
                  }
                  int length=skinpixel.length;
                  for(int i=0;i&lt;length;i++)
                      System.out.println(skinpixel[i]+"\n");
  
              }
  
              catch(Exception e)
              {
                  e.printStackTrace();
              }
  
  
          }
  
          public static void main(String args[])
          {
  
              demo2 dem=new demo2();
              dem.skindet();
          }
  
      }
  </code></pre>
  
  <p>The exception is </p>
  
  <p>java.lang.ArrayIndexOutOfBoundsException: 3
          at demo2.skindet(demo2.java:44)
          at demo2.main(demo2.java:79)</p>
  
  <p>Thank You for replying.Regards</p>