Question

我的问题是我拍了一张图像然后我改变了一些像素值然后将它们设置到所需的位置然后我写了图像然后我使用ImageIO.read（）通过使用我没有得到的图像对象读取图像以前的值...所以我怎样才能得到以前的值

import java.awt.*;

import java.awt.event.*;

import java.awt.image.*;

import java.io.*;

import javax.imageio.*;

import javax.swing.*;


public class LoadImageApp extends JFrame implements ActionListener

{

      BufferedImage img=null;
  BufferedImage img1=null;
  BufferedImage mask=null;
  BufferedImage rao=null;
      JButton b1;
  int pixel[][];
  int w,h;
  JFileChooser chooser;
  File file;
      public void paint(Graphics g)
      {
         g.drawImage(img,50,50,150,200,this);
     g.drawImage(mask,600,100,150,200,this);

      }

  public LoadImageApp()
      {  
         super("Image...");
     setSize(800,800);
     setLayout(new FlowLayout());
     b1=new JButton("Select Image");
     b1.setSize(250,20);
     add(b1);
     b1.addActionListener(this);
     setVisible(true);
      }
  public void actionPerformed(ActionEvent ae)
  {
     try
     {  

                    chooser = new JFileChooser("C:/Users/Ravi/Desktop");
            chooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
                int returnVal = chooser.showOpenDialog(this);
                if(returnVal == JFileChooser.APPROVE_OPTION) 
            {
             file=chooser.getSelectedFile();
             img=ImageIO.read(file);
             mask=new BufferedImage(img.getWidth(),img.getHeight(),img.getType());
             repaint();
             img1=img.getSubimage(0,0,100,150);
                }
            repaint();
            pixel=getPixels(img);
            int i=80,j=50;
            int temp[]={1,1,1,1};
            int temp1=setPixel(temp);
            for(j=0;j<w;j++)
             pixel[i][j]=temp1;
            System.out.println("pixels before.."+pixel[80][3]);
            this.setPixels();//setting pixels....
            ImageIO.write(mask,"jpeg",new File("aft-con.jpeg"));//write the image

           BufferedImage next=ImageIO.read(new File("aft-con.jpeg"));
           ord=getPixels(next);//getting the previous values...
           org=getARGB(ord[80][3]);
           System.out.println("pixels before.."+pixel[80][3]);//but it is not same...

         }
         catch(Exception e)
         {
            System.out.println("error in action");
         }
   }
   public int setPixel(int rgb[])
   {
        int pixel = (((rgb[0] & 0x0ff)<<24)|((rgb[1] & 0x0ff)<<16)|((rgb[2] & 0x0ff)<<8)|(rgb[3] & 0x0ff));
        return pixel;
   }
   public int[] getARGB(int pixel)
   {
          int rgb[]=new int[4];
          rgb[0] =((pixel >> 24) & 0xff);
          rgb[1] = ((pixel >> 16) & 0xff);
          rgb[2] =((pixel >> 8) & 0xff);
          rgb[3] =((pixel ) & 0xff);

           return rgb;
    }

    public int[][] getPixels(BufferedImage img)
   { 
      w=img.getWidth();
      h=img.getHeight();
      int pixels[][]=new int[h][w];

     int i=0,j=0;
     try
     {
       for(i=0;i<h;i++)
        for(j=0;j<w;j++)
            pixels[i][j]=img.getRGB(j,i);

     }
     catch(Exception e)
     {
         System.out.println("i:"+i+" j:"+j);
     }


     return pixels;
 }
 public void setPixels()
 {
      w=img.getWidth();
      h=img.getHeight();

          int i=0,j=0;
      try
      {
       for(i=0;i<h;i++)
         for(j=0;j<w;j++)
         mask.setRGB(j,i,pixel[i][j]);
      }
      catch(Exception e)
      {
                System.out.println("error at setting pixel");
      }
 }

     public static void main(String[] args) 
     {

        LoadImageApp f = new LoadImageApp();
            f.addWindowListener(new WindowAdapter(){
            public void windowClosing(WindowEvent e) {
            System.exit(0);
             }
           });
    }

}

Answer 1

当图像保存为JPEG时，它会被压缩。这导致像素值的改变。如果您不希望发生任何更改，则需要以无损格式保存，例如： PNG。

使用imageio.read在设置像素后获取错误的像素值

1 个答案: