saveimage.java

java tutorial.sun公司官方出品。java入门书籍。最新版

/*
 * Copyright (c) 1995 - 2008 Sun Microsystems, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Sun Microsystems nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */ 


import java.io.*;
import java.util.TreeSet;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.AffineTransform;
import java.awt.image.*;
import javax.imageio.*;
import javax.swing.*;

public class SaveImage extends Component implements ActionListener {

    String descs[] = {
    "Original", 
        "Convolve : LowPass",
        "Convolve : Sharpen", 
        "LookupOp",
    };

    int opIndex;
    private BufferedImage bi, biFiltered;
    int w, h;
    
    public static final float[] SHARPEN3x3 = { // sharpening filter kernel
        0.f, -1.f,  0.f,
       -1.f,  5.f, -1.f,
        0.f, -1.f,  0.f
    };

    public static final float[] BLUR3x3 = {
        0.1f, 0.1f, 0.1f,    // low-pass filter kernel
        0.1f, 0.2f, 0.1f,
        0.1f, 0.1f, 0.1f
    };

    public SaveImage() {
        try {
            bi = ImageIO.read(new File("bld.jpg"));
            w = bi.getWidth(null);
            h = bi.getHeight(null);
            if (bi.getType() != BufferedImage.TYPE_INT_RGB) {
                BufferedImage bi2 =
                    new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
                Graphics big = bi2.getGraphics();
                big.drawImage(bi, 0, 0, null);
                biFiltered = bi = bi2;
            }
        } catch (IOException e) {
            System.out.println("Image could not be read");
            System.exit(1);
        }
    }

    public Dimension getPreferredSize() {
        return new Dimension(w, h);
    }

    String[] getDescriptions() {
        return descs;
    }

    void setOpIndex(int i) {
        opIndex = i;
    }

    public void paint(Graphics g) {
        filterImage();
        g.drawImage(biFiltered, 0, 0, null);
    }

    int lastOp;
    public void filterImage() {
        BufferedImageOp op = null;

        if (opIndex == lastOp) {
            return;
        }
        lastOp = opIndex;
        switch (opIndex) {

        case 0: biFiltered = bi; /* original */
                return; 
        case 1:  /* low pass filter */
        case 2:  /* sharpen */
            float[] data = (opIndex == 1) ? BLUR3x3 : SHARPEN3x3;
            op = new ConvolveOp(new Kernel(3, 3, data),
                                ConvolveOp.EDGE_NO_OP,
                                null);
  
            break;

        case 3 : /* lookup */
            byte lut[] = new byte[256];
            for (int j=0; j<256; j++) {
                lut[j] = (byte)(256-j); 
            }
            ByteLookupTable blut = new ByteLookupTable(0, lut); 
            op = new LookupOp(blut, null);
            break;
        }

        /* Rather than directly drawing the filtered image to the
         * destination, filter it into a new image first, then that
         * filtered image is ready for writing out or painting. 
         */
        biFiltered = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
        op.filter(bi, biFiltered);
    }

    /* Return the formats sorted alphabetically and in lower case */
    public String[] getFormats() {
        String[] formats = ImageIO.getWriterFormatNames();
        TreeSet<String> formatSet = new TreeSet<String>();
        for (String s : formats) {
            formatSet.add(s.toLowerCase());
        }
        return formatSet.toArray(new String[0]);
    }


     public void actionPerformed(ActionEvent e) {
         JComboBox cb = (JComboBox)e.getSource();
         if (cb.getActionCommand().equals("SetFilter")) {
             setOpIndex(cb.getSelectedIndex());
             repaint();
         } else if (cb.getActionCommand().equals("Formats")) {
             /* Save the filtered image in the selected format.
              * The selected item will be the name of the format to use
              */
             String format = (String)cb.getSelectedItem();
             /* Use the format name to initialise the file suffix.
              * Format names typically correspond to suffixes
              */
             File saveFile = new File("savedimage."+format);
             JFileChooser chooser = new JFileChooser();
             chooser.setSelectedFile(saveFile);
             int rval = chooser.showSaveDialog(cb);
             if (rval == JFileChooser.APPROVE_OPTION) {
                 saveFile = chooser.getSelectedFile();
                 /* Write the filtered image in the selected format,
                  * to the file chosen by the user.
                  */
                 try {
                     ImageIO.write(biFiltered, format, saveFile);
                 } catch (IOException ex) {
                 }
             }
         }
    };

    public static void main(String s[]) {
        JFrame f = new JFrame("Save Image Sample");
        f.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {System.exit(0);}
        });
        SaveImage si = new SaveImage();
        f.add("Center", si);
        JComboBox choices = new JComboBox(si.getDescriptions());
        choices.setActionCommand("SetFilter");
        choices.addActionListener(si);
        JComboBox formats = new JComboBox(si.getFormats());
        formats.setActionCommand("Formats");
        formats.addActionListener(si);
        JPanel panel = new JPanel();
        panel.add(choices);
        panel.add(new JLabel("Save As"));
        panel.add(formats);
        f.add("South", panel);
        f.pack();
        f.setVisible(true);
    }
}