10.2图片处理

从硬盘读取图片

Image image = null;
    try {
        // Read from a file
        File file = new File("image.gif");
        image = ImageIO.read(file);
    
        // Read from an input stream
        InputStream is = new BufferedInputStream(
            new FileInputStream("image.gif"));
        image = ImageIO.read(is);
    
        // Read from a URL
        URL url = new URL("http://hostname.com/image.gif");
        image = ImageIO.read(url);
    } catch (IOException e) {
    }
    
    // Use a label to display the image
    JFrame frame = new JFrame();
    JLabel label = new JLabel(new ImageIcon(image));
    frame.getContentPane().add(label, BorderLayout.CENTER);
    frame.pack();
    frame.setVisible(true);

产生缩略图  和  使两个图片合并到一起

import java.awt.AWTException;
import java.awt.Graphics;
import java.awt.HeadlessException;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;

public class MyImage extends JFrame{
    
    @SuppressWarnings("deprecation")
    public MyImage(){
        JLabel jl = new JLabel();
        //Image im = this.getImage();
        Image im = null;
        try {
            im = this.margeImages();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        ImageIcon ic = new ImageIcon(im);
        jl.setIcon(ic);
        this.add(jl);
        this.setSize(600,450);
        this.show();
    }
    
    public static void main(String[] args){
        new MyImage();
    }
    
    public Image getImage(){
        Image img = null;
        try {
            /*
             * 截屏并产生缩略图
             */
            Robot myrobot = new Robot();
            BufferedImage bi = myrobot.createScreenCapture(new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()));
            /*
             * 产生缩略图的方法
             */
            img = bi.getScaledInstance(360, 250, BufferedImage.SCALE_AREA_AVERAGING);
            
            } catch (AWTException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return img;
    }
    
    public Image margeImages() throws IOException{
        BufferedImage b = null;
        Image img1 = null;
        Image img = null;
        try {
            /*
             * 截全屏
             */
            b = new Robot().createScreenCapture(new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()));
            img = b.getScaledInstance(b.getWidth(), b.getHeight(), BufferedImage.SCALE_SMOOTH);
            img1 = b.getScaledInstance(300, 200, BufferedImage.SCALE_SMOOTH);
        } catch (HeadlessException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (AWTException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        /*
         * 获得画布
         */
        Graphics my_g = b.getGraphics();
        /*
         * 画另一副图
         */
        my_g.drawImage(img1, 100, 100, 200, 400,null);
        //my_g.drawImage(img,0,0,b.getWidth(), b.getHeight(),null);
        /*
         * 释放相应的资源
         */
        my_g.dispose();
        return img;
    }

}