java如何转换图片格式，高分求助，急！！

[lionheartliu]

小弟是一名菜鸟，现在要转换图片格式，如：把jpg转换成bmp、把tif转换成jpg等，那位大虾有通用的转换图片格式的程序或好的方法，请不吝赐教，如有程序请详细贴出来，试验成功后一定高分相送！急！

[dreamno]

jdk里有专门的api你可以找找.忘记是啥了。好象是...Stream.class

[dreamno]

BufferedImage

[dreamno]

package com.liming.applet;

import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.swing.*;
import java.io.*;
import java.net.*;
import javax.imageio.*;

public class Converting
extends JFrame {
JLabel promptLabel;
JTextField prompt;
JButton promptButton;
JFileChooser fileChooser;
JComboBox comboBox;
JButton saveButton;
public Converting() {
super("Image Conversion");
setDefaultCloseOperation(EXIT_ON_CLOSE);
Container contentPane = getContentPane();
JPanel inputPanel = new JPanel();
promptLabel = new JLabel("Filename:");
inputPanel.add(promptLabel);
prompt = new JTextField(20);
inputPanel.add(prompt);
promptButton = new JButton("Browse");
inputPanel.add(promptButton);
contentPane.add(inputPanel, BorderLayout.NORTH);
fileChooser = new JFileChooser();
promptButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int returnValue = fileChooser.showOpenDialog(null);
if (returnValue == JFileChooser.APPROVE_OPTION) {
File selectedFile = fileChooser.getSelectedFile();
if (selectedFile != null) {
prompt.setText(selectedFile.getAbsolutePath());
}
}
}
});
JPanel outputPanel = new JPanel();
String writerFormats[] = ImageIO.getWriterFormatNames();
ComboBoxModel comboBoxModel = new DefaultComboBoxModel(writerFormats);
comboBox = new JComboBox(comboBoxModel);
outputPanel.add(comboBox);
saveButton = new JButton("Save");
outputPanel.add(saveButton);
saveButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
try {
String name = prompt.getText();
File file = new File(name);
if (file.exists()) {
BufferedImage image = ImageIO.read(file.toURL());
if (image == null) {
System.err.println(
"Invalid input file format");
}
else {
String selection = (String
) comboBox.getSelectedItem();
String outputFilename = name + "." + selection;
File outputFile = new File(outputFilename);
boolean found = ImageIO.write(image, selection,
outputFile);
if (found) {
JDialog window = new JDialog();
Container windowContent = window.getContentPane();
BufferedImage newImage = ImageIO.read(
outputFile);
JLabel label = new JLabel(new ImageIcon(
newImage));
JScrollPane pane = new JScrollPane(label);
windowContent.add(pane, BorderLayout.CENTER);
window.setSize(300, 300);
window
.show();
}
else {
System.err.println("Error saving");
}
}
}
else {
System.err.println("Bad filename");
}
}
catch (MalformedURLException mur) {
System.err.println("Bad filename");
}
catch (IOException ioe) {
System.err.println("Error reading file");
}
}
});
contentPane.add(outputPanel, BorderLayout.SOUTH);
}

public static void main(String args[]) {
JFrame frame = new Converting();
frame.pack();
frame.show();
}
}

[lionheartliu]

没人回答吗？自己顶一下，希望高手出招！

[dreamno]

public static boolean convert(String source,String target){
try {
RenderedOp rop = JAI.create("fileload", source);
OutputStream outStream = new FileOutputStream(target);
BMPEncodeParam param = new BMPEncodeParam();
ImageEncoder imageEncoder = ImageCodec.createImageEncoder("BMP",
outStream,
param);
imageEncoder.encode(rop);
outStream.close();
}
catch(Exception ex){
return false;
}
return true;
}

[dreamno]

需要jai_codec.jar,jai_core.jar这两个包。
可以在：
http://java.sun.com/products/java-media/jai/downloads/download-iio.html
下在到.如果不行的话。你给我留个
mail我给你发过去。

[lionheartliu]

dreamno,你好，我看了你的程序，给了我一些启发，但是执行你的程序后，总是显示“Invalid input file format”，我选择的是tif格式的图片文件，要转换成jpg的格式，我选择bmp的都不行，请问为什么，