Saturday, May 18, 2013

Image brightness


The ImageBrightness program allows you to selection an image file. When the image displays on the program window you can slide the knob  left or right to change the brightness of the image. After you make change to the image, you can save the updated image in a separated file or override the original image file.

ImageBrightness source code:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import java.awt.image.*;
import javax.swing.filechooser.*;
import java.io.*;
import java.awt.*;
import java.awt.geom.*;
import javax.imageio.*;
import javax.imageio.stream.*;

class ImgArea extends Canvas{
                        Image orImg;
                        BufferedImage orBufferedImage;
                        BufferedImage bimg;
                        float e=0.0f;
                        Dimension ds;
                        int mX;
                        int mY;
                        int x;
                        int y;
                        boolean imageLoaded;
                        boolean actionPerf;

                        public ImgArea(){
                                    imageLoaded=false;           
                                    actionPerf=false;
                        }
                       
1                      public void paint(Graphics g){
                                    Graphics2D g2d=(Graphics2D)g;                        
                                    g2d.translate(mX,mY);
                                    if(imageLoaded){ //the image loaded
                                                if(actionPerf) //the image have been changed
                                                            g2d.drawImage(bimg,x,y,this);
                                                else
                                                            g2d.drawImage(orBufferedImage,x,y,this);
                                    }
                                    g2d.dispose(); //clear graphics object
                                   
                        }

2                      public void prepareImage(String filename){

                                    try{
                                    MediaTracker mt=new MediaTracker(this);//Create MediaTracker object
                                    //to track the image load                             
                                    orImg=Toolkit.getDefaultToolkit().getImage(filename); //read the image file
                                    mt.addImage(orImg,0);//add image to the tracker
                                    mt.waitForID(0);        //wait for the image to fully load                
                                    if(orImg==null) System.exit(-1); //if no valid image selected exit the program
                                    ds=getToolkit().getScreenSize(); //get the size of screen
                                    //new coordinate to move the original coordinate to                             
                                    mX=(int)ds.getWidth()/2;
                                    mY=(int)ds.getHeight()/2;
                                    //coordinate to show the image on the screen
                                    x=-orImg.getWidth(this)/2;
                                    y=-orImg.getHeight(this)/2;
                                    //get the size of the orignal image
                                    int width=orImg.getWidth(null);
                                    int height=orImg.getHeight(null);
                                    //Create BufferedImage object from the original image
                                    orBufferedImage=createBufferedImageFromImage(orImg,width,height);
                                    //Create the blank BufferedImage object                        
                                    bimg = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);          
                                    imageLoaded=true; //now the image loaded
                                    }catch(Exception e){System.exit(-1);}
                        }

3                      public void filterImage(){
                                    //Define elements array used for Kernel object
                                    float[] elements = {0.0f, 1.0f, 0.0f, -1.0f,e,1.0f,0.0f,0.0f,0.0f};
                                    //create Kernel object kernel from the elements array
                                    Kernel kernel = new Kernel(3, 3, elements);
                                    //Create ConvolveOp object cop to wrap the kernel object
                                    ConvolveOp cop = new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null);
                                    //filtering the image
                                    //destination image is placed in BufferedImage object bimg for later showing and saving
                                    cop.filter(orBufferedImage,bimg);
                                   
                        }

4                      public void setValue(float value){
                                    e=value;
                        }

5                      public void setActionPerf(boolean value ){        
                                    actionPerf=value;
                        }
                       

6          public BufferedImage createBufferedImageFromImage(Image image, int width, int height)
            {
                        BufferedImage dest = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
                        Graphics2D g2 = dest.createGraphics();
                        g2.drawImage(image, 0, 0, null);
                        g2.dispose();
                        return dest;
            }

7          public void saveToFile(String filename){
                        String ftype=filename.substring(filename.lastIndexOf('.')+1); //get file extension
                        try{
                                    if(actionPerf) //there is a change to the image so save it
                                                ImageIO.write(bimg,ftype,new File(filename));
                           }catch(IOException e){System.out.println("Error in saving the file");}
                        }
}

class  Main extends JFrame implements ChangeListener, ActionListener{
           
            JSlider jsd;
            ImgArea ia;
            JFileChooser chooser;
            JMenuBar mainmenu;
            JMenu menu;
            JMenuItem mopen;
            JMenuItem msaveas;
            JMenuItem msave;
            JMenuItem mexit;    
            String filename;
            boolean actionPerf;
            Main(){
                        ia=new ImgArea();
                        jsd=new JSlider(-10,10,0); 
                        jsd.setEnabled(false);
                        Container cont=getContentPane();
                        jsd.addChangeListener(this);
                        cont.add(ia,BorderLayout.CENTER );
                        cont.add(jsd,BorderLayout.SOUTH);       

                        mainmenu=new JMenuBar();
                        menu=new JMenu("File");
                        menu.setMnemonic(KeyEvent.VK_F);

                        mopen=new JMenuItem("Open...");
                        mopen.setMnemonic(KeyEvent.VK_O);
                        mopen.addActionListener(this);

                        msaveas=new JMenuItem("Save as...");
                        msaveas.setMnemonic(KeyEvent.VK_S);
                        msaveas.addActionListener(this);

                        msave=new JMenuItem("Save");
                        msave.setMnemonic(KeyEvent.VK_V);
                        msave.addActionListener(this);                

                        mexit=new JMenuItem("Exit");
                        mexit.setMnemonic(KeyEvent.VK_X);
                        mexit.addActionListener(this);
                        menu.add(mopen);
                        menu.add(msaveas);
                        menu.add(msave);
                        menu.add(mexit);
                        mainmenu.add(menu);
                        setJMenuBar(mainmenu);
           
                        setTitle("Image Brightness");
                        setDefaultCloseOperation(EXIT_ON_CLOSE);
                        setExtendedState(this.getExtendedState() | this.MAXIMIZED_BOTH);
                        setVisible(true);       

                        chooser = new JFileChooser();
                        FileNameExtensionFilter filter = new FileNameExtensionFilter("Image files", "jpg", "gif","bmp","png");
                        chooser.setFileFilter(filter);
                        chooser.setMultiSelectionEnabled(false);
                        enableSaving(false);
                        }

8          public void actionPerformed(ActionEvent e){

                        JMenuItem source = (JMenuItem)(e.getSource());
                        if(source.getText().compareTo("Open...")==0) //The Open sub-menu item is selected
                                                {
                                                setImage();
                                                ia.repaint();
                                                      validate();
                                                                       
                                                            }
                        else if(source.getText().compareTo("Save as...")==0) //The Save as sub-menu item is selected
                                                {
                                                showSaveFileDialog();      
                                                                       
                                                            }
                        else if(source.getText().compareTo("Save")==0) //The Save sub-menu item is selected
                                                {
                                                           
                                                ia.saveToFile(filename);                
                                                            }
                       
                        else if(source.getText().compareTo("Exit")==0) //The Exit sub-menu item is selected
                                                System.exit(0);
                                                           
                                               
                        }          
                       

9          public void setImage(){
                       
                        int returnVal = chooser.showOpenDialog(this);
                        if(returnVal == JFileChooser.APPROVE_OPTION) {                           
                                    filename=chooser.getSelectedFile().toString();
                                    ia.prepareImage(filename); //prepare image for show
                                    jsd.setEnabled(true); //enable the slider
                                    jsd.requestFocus(); //move focus to the slider
                                                }
                                
                        }

10        public void showSaveFileDialog(){
                         int returnVal = chooser.showSaveDialog(this);
                         if(returnVal == JFileChooser.APPROVE_OPTION) { 
                                    String filen=chooser.getSelectedFile().toString();
                                                ia.saveToFile(filen);            
           
                          }
 }

11        public void stateChanged(ChangeEvent e){
                        ia.setValue(jsd.getValue()/10.0f);
                        ia.filterImage();
                        ia.repaint();
                        ia.setActionPerf(actionPerf=true);//tells the ImgShow object that there is any change to the image
                        enableSaving(true); //enable Save as... and Save sub-menu items
                        }

12        public void enableSaving(boolean f){
                        msaveas.setEnabled(f);
                        msave.setEnabled(f);         
                       
            }

}

public class ImageBrightness{
 
            public static void main(String args[]){
                          new Main();
  
            }


}

Image brightness or brighter in Java




Code Explanation:
1 The paint method of the Canvas class has code to display the image.
2 The prepareImage method has code to read the image file, track its loading, define coordinates to
move the original coordinate to and to show the image on the screen, create BufferedImage object from
the original image, and to create a blank BufferedImage object to be the result image of making change to the
original image.
3 The filterImage method is implemented to transfer the result image or updated image to the BufferedImage  object bimg for later showing and saving.
4 The setValue method has code to assign the value of the slider to the e variable of the ImgArea class. This value is used in the elements array that is used to construct the kernel object for image filtering process.
5 The setActionPerf method has code to assign the boolean value true or false to the actionPer variable of ImgArea class to indicate any change been made to the image.
6 The createBufferedImageFromImage has code to create an BufferedImage object from the original image.
7 The saveToFile method is invoked when the user select Save as... or Save sub-menu item to save the updated image to you current working folder.
8 The actionPerform method of the ActionListener interface is rewritten to enable menu items selection and do the action accordingly.
9 The setImage method displays the open file dialog for image file selection. The selected image file will be sent to ia object(created from ImgArea class) for showing on the screen.
10 The showSaveDialog is invoked when the user selects Save as.. sub-menu item. Its displays the save file
dialog so the user can save the updated image in a separed file.
11 The stateChanged method of the ChangeListener interface is rewritten to track any change made to the original image.
12 The enableSaving method is invoked to enable or disable the sub-menu items: Save as... or Save. When
the program firstly loads and there is no change to the image, they are disabled. They are reenabled after
any change to the image.

For more detain code explanation, please read the comments in code of the program.

1 comment:

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