corejava/corejava第10版/v2ch11/imageProcessing/ImageProcessingFrame.java

package imageProcessing;

import java.awt.*;
import java.awt.geom.*;
import java.awt.image.*;
import java.io.*;

import javax.imageio.*;
import javax.swing.*;
import javax.swing.filechooser.*;

/**
 * This frame has a menu to load an image and to specify various transformations, and a component to
 * show the resulting image.
 */
public class ImageProcessingFrame extends JFrame
{
   private static final int DEFAULT_WIDTH = 400;
   private static final int DEFAULT_HEIGHT = 400;

   private BufferedImage image;

   public ImageProcessingFrame()
   {
      setTitle("ImageProcessingTest");
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

      add(new JComponent()
         {
            public void paintComponent(Graphics g)
            {
               if (image != null) g.drawImage(image, 0, 0, null);
            }
         });

      JMenu fileMenu = new JMenu("File");
      JMenuItem openItem = new JMenuItem("Open");
      openItem.addActionListener(event -> openFile());
      fileMenu.add(openItem);

      JMenuItem exitItem = new JMenuItem("Exit");
      exitItem.addActionListener(event -> System.exit(0));
      fileMenu.add(exitItem);

      JMenu editMenu = new JMenu("Edit");
      JMenuItem blurItem = new JMenuItem("Blur");
      blurItem.addActionListener(event ->
         {
            float weight = 1.0f / 9.0f;
            float[] elements = new float[9];
            for (int i = 0; i < 9; i++)
               elements[i] = weight;
            convolve(elements);
         });
      editMenu.add(blurItem);

      JMenuItem sharpenItem = new JMenuItem("Sharpen");
      sharpenItem.addActionListener(event ->
         {
            float[] elements = { 0.0f, -1.0f, 0.0f, -1.0f, 5.f, -1.0f, 0.0f, -1.0f, 0.0f };
            convolve(elements);
         });
      editMenu.add(sharpenItem);

      JMenuItem brightenItem = new JMenuItem("Brighten");
      brightenItem.addActionListener(event ->
         {
            float a = 1.1f;
            float b = 20.0f;
            RescaleOp op = new RescaleOp(a, b, null);
            filter(op);
         });
      editMenu.add(brightenItem);

      JMenuItem edgeDetectItem = new JMenuItem("Edge detect");
      edgeDetectItem.addActionListener(event ->
         {
            float[] elements = { 0.0f, -1.0f, 0.0f, -1.0f, 4.f, -1.0f, 0.0f, -1.0f, 0.0f };
            convolve(elements);
         });
      editMenu.add(edgeDetectItem);

      JMenuItem negativeItem = new JMenuItem("Negative");
      negativeItem.addActionListener(event ->
         {
            short[] negative = new short[256 * 1];
            for (int i = 0; i < 256; i++)
               negative[i] = (short) (255 - i);
            ShortLookupTable table = new ShortLookupTable(0, negative);
            LookupOp op = new LookupOp(table, null);
            filter(op);
         });
      editMenu.add(negativeItem);

      JMenuItem rotateItem = new JMenuItem("Rotate");
      rotateItem.addActionListener(event ->
         {
            if (image == null) return;
            AffineTransform transform = AffineTransform.getRotateInstance(Math.toRadians(5),
                  image.getWidth() / 2, image.getHeight() / 2);
            AffineTransformOp op = new AffineTransformOp(transform,
                  AffineTransformOp.TYPE_BICUBIC);
            filter(op);
         });
      editMenu.add(rotateItem);

      JMenuBar menuBar = new JMenuBar();
      menuBar.add(fileMenu);
      menuBar.add(editMenu);
      setJMenuBar(menuBar);
   }

   /**
    * Open a file and load the image.
    */
   public void openFile()
   {
      JFileChooser chooser = new JFileChooser(".");
      chooser.setCurrentDirectory(new File(getClass().getPackage().getName()));
      String[] extensions = ImageIO.getReaderFileSuffixes();
      chooser.setFileFilter(new FileNameExtensionFilter("Image files", extensions));
      int r = chooser.showOpenDialog(this);
      if (r != JFileChooser.APPROVE_OPTION) return;

      try
      {
         Image img = ImageIO.read(chooser.getSelectedFile());
         image = new BufferedImage(img.getWidth(null), img.getHeight(null),
               BufferedImage.TYPE_INT_RGB);
         image.getGraphics().drawImage(img, 0, 0, null);
      }
      catch (IOException e)
      {
         JOptionPane.showMessageDialog(this, e);
      }
      repaint();
   }

   /**
    * Apply a filter and repaint.
    * @param op the image operation to apply
    */
   private void filter(BufferedImageOp op)
   {
      if (image == null) return;
      image = op.filter(image, null);
      repaint();
   }

   /**
    * Apply a convolution and repaint.
    * @param elements the convolution kernel (an array of 9 matrix elements)
    */
   private void convolve(float[] elements)
   {
      Kernel kernel = new Kernel(3, 3, elements);
      ConvolveOp op = new ConvolveOp(kernel);
      filter(op);
   }
}