|
How to crop a subimage from an image |
|
|
You can use the following code to crop a subimage from an image.
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.io.*;
import javax.imageio.ImageIO;
import javax.swing.*;
import javax.swing.event.MouseInputAdapter;
public class Cropping extends JPanel
{
BufferedImage image;
Dimension size;
Rectangle clip;
boolean showClip;
public Cropping(BufferedImage image)
{
this.image = image;
size = new Dimension(image.getWidth(), image.getHeight());
showClip = false;
}
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
int x = (getWidth() - size.width)/2;
int y = (getHeight() - size.height)/2;
g2.drawImage(image, x, y, this);
if(showClip)
{
if(clip == null)
createClip();
g2.setPaint(Color.red);
g2.draw(clip);
}
}
public void setClip(int x, int y)
{
// keep clip within raster
int x0 = (getWidth() - size.width)/2;
int y0 = (getHeight() - size.height)/2;
if(x < x0 || x + clip.width > x0 + size.width ||
y < y0 || y + clip.height > y0 + size.height)
return;
clip.setLocation(x, y);
repaint();
}
public Dimension getPreferredSize()
{
return size;
}
private void createClip()
{
clip = new Rectangle(140, 140);
clip.x = (getWidth() - clip.width)/2;
clip.y = (getHeight() - clip.height)/2;
}
private void clipImage()
{
BufferedImage clipped = null;
try
{
int w = clip.width;
int h = clip.height;
int x0 = (getWidth() - size.width)/2;
int y0 = (getHeight() - size.height)/2;
int x = clip.x - x0;
int y = clip.y - y0;
clipped = image.getSubimage(x, y, w, h);
}
catch(RasterFormatException rfe)
{
System.out.println("raster format error: " + rfe.getMessage());
return;
}
JLabel label = new JLabel(new ImageIcon(clipped));
JOptionPane.showMessageDialog(this, label, "clipped image",
JOptionPane.PLAIN_MESSAGE);
}
private JPanel getUIPanel()
{
final JCheckBox clipBox = new JCheckBox("show clip", showClip);
clipBox.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
showClip = clipBox.isSelected();
repaint();
}
});
JButton clip = new JButton("clip image");
clip.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
clipImage();
}
});
JPanel panel = new JPanel();
panel.add(clipBox);
panel.add(clip);
return panel;
}
public static void main(String[] args) throws IOException
{
File file = new File("images/cougar.jpg");
Cropping test = new Cropping(ImageIO.read(file));
ClipMover mover = new ClipMover(test);
test.addMouseListener(mover);
test.addMouseMotionListener(mover);
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.getContentPane().add(new JScrollPane(test));
f.getContentPane().add(test.getUIPanel(), "South");
f.setSize(400,400);
f.setLocation(200,200);
f.setVisible(true);
}
}
class ClipMover extends MouseInputAdapter
{
Cropping cropping;
Point offset;
boolean dragging;
public ClipMover(Cropping c)
{
cropping = c;
offset = new Point();
dragging = false;
}
public void mousePressed(MouseEvent e)
{
Point p = e.getPoint();
if(cropping.clip.contains(p))
{
offset.x = p.x - cropping.clip.x;
offset.y = p.y - cropping.clip.y;
dragging = true;
}
}
public void mouseReleased(MouseEvent e)
{
dragging = false;
}
public void mouseDragged(MouseEvent e)
{
if(dragging)
{
int x = e.getX() - offset.x;
int y = e.getY() - offset.y;
cropping.setClip(x, y);
}
}
}
|
Related Tips
|
Page 1 of 0 ( 0 comments )
Java SE Tips 
You can share your information about this topic using the form below!
Please do not post your questions with this form! Thanks.