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
我目前正在做一个关于隐写术的项目，使用离散小波变换。我已经编写并编译了代码。然而，我面临着一些例外。请帮我解释一下这些例外情况。例外情况如下
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)
I am new in Stack Overflow.Forgive me if I have made any mistake while posting the question. Thank You
我是栈溢出的新手。如果我在发布问题时犯了任何错误，请原谅。谢谢你！
Re: Sorry Sir I am still getting acquainted to the rules of the forum.
对不起，先生，我还在熟悉论坛的规则。
The code for detection of skin region in an image is
图像中皮肤区域的检测代码是
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<w;i++)
{
for (int j=0;j<h;j++)
{
rgb[i][j] =image.getRGB(i,j);
red=(rgb[i][j] >> 16) & 0xff;
green=(rgb[i][j] >> 8) & 0xff;
blue=(rgb[i][j]) & 0xff;
float[] values = Color.RGBtoHSB(red,green,blue,null);
for(int s=0;s<3;s++)
{
hsvval[counter]=values[s];
counter++;
}
hue=hsvval[0];
sat=hsvval[1];
val=hsvval[2];
if(hue>0 && hue<0.11 && sat>0.2 && sat<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<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();
}
}
The exception is
唯一的例外是
java.lang.ArrayIndexOutOfBoundsException: 3 at demo2.skindet(demo2.java:44) at demo2.main(demo2.java:79)
. lang。ArrayIndexOutOfBoundsException: 3 at demo2.skindet(demo2.java:44) at demo2.main(demo2.java:79)
Thank You for replying.Regards
谢谢你replying.Regards
1 个解决方案
#1
2
It means that you're calling Integer.parseInt from line 292 of Steganography.java (which unusually appears to hold a class called DWT rather than Steganography), but you're providing a null value.
它表示你调用的是整数。从第292行开始。java(不同寻常的是，它包含一个名为DWT的类，而不是隐写)，但是您提供了一个空值。
It looks like this is in response to some action being performed on a text field.
看起来这是对在文本字段上执行的一些操作的响应。
We can't really tell a lot more without seeing your code - you need to work out why the value is null.
在没有看到代码的情况下，我们不能透露更多信息——您需要找出为什么值为null。
EDIT: Okay, now that it's changed to a completely different error, this is the problem:
编辑:好的，现在它变成了一个完全不同的错误，这就是问题所在:
int counter = 0;
hsvval=new float[3];
...
for (int i=0;i<w;i++)
{
for (int j=0;j<h;j++)
{
...
for(int s=0;s<3;s++)
{
hsvval[counter]=values[s];
counter++;
}
...
}
}
So the first time the inner loop is executed, it's fine - but on the second iteration of the middle loop (j = 1), you haven't reset counter, so it's 3 - which is out of range. You've got the same problem with scount later.
因此，第一次执行内部循环时，它是可以的——但是在中间循环的第二次迭代(j = 1)中，您没有重置计数器，所以它是3 -，这超出了范围。你以后也会遇到同样的问题。
If you declare and initialize count and scount just before they're used in the inner loop, it's fine.
如果在内部循环中使用count和scount之前声明并初始化计数和scount，那就可以了。
#1
2
It means that you're calling Integer.parseInt from line 292 of Steganography.java (which unusually appears to hold a class called DWT rather than Steganography), but you're providing a null value.
它表示你调用的是整数。从第292行开始。java(不同寻常的是，它包含一个名为DWT的类，而不是隐写)，但是您提供了一个空值。
It looks like this is in response to some action being performed on a text field.
看起来这是对在文本字段上执行的一些操作的响应。
We can't really tell a lot more without seeing your code - you need to work out why the value is null.
在没有看到代码的情况下，我们不能透露更多信息——您需要找出为什么值为null。
EDIT: Okay, now that it's changed to a completely different error, this is the problem:
编辑:好的，现在它变成了一个完全不同的错误，这就是问题所在:
int counter = 0;
hsvval=new float[3];
...
for (int i=0;i<w;i++)
{
for (int j=0;j<h;j++)
{
...
for(int s=0;s<3;s++)
{
hsvval[counter]=values[s];
counter++;
}
...
}
}
So the first time the inner loop is executed, it's fine - but on the second iteration of the middle loop (j = 1), you haven't reset counter, so it's 3 - which is out of range. You've got the same problem with scount later.
因此，第一次执行内部循环时，它是可以的——但是在中间循环的第二次迭代(j = 1)中，您没有重置计数器，所以它是3 -，这超出了范围。你以后也会遇到同样的问题。
If you declare and initialize count and scount just before they're used in the inner loop, it's fine.
如果在内部循环中使用count和scount之前声明并初始化计数和scount，那就可以了。