java绘图缩放代码大全 java缩小图片大小

怎么用java代码放大或缩小图片不失真。

放大图像不会导致失真，而缩小图像将不可避免的失真。

Java中也同样是这样。

但java提供了4个缩放的微调选项。

image.SCALE_SMOOTH //平滑优先

image.SCALE_FAST//速度优先

image.SCALE_AREA_AVERAGING //区域均值

image.SCALE_REPLICATE //像素复制型缩放

image.SCALE_DEFAULT //默认缩放模式

调用方法

Image new_img=old_img.getScaledInstance(1024, 768, Image.SCALE_SMOOTH);

得到一张缩放后的新图。

相关问答

Q1: java 图片缩放代码

直接给你一个类，直接套用就好了

import java.awt.Graphics2D;

import java.awt.RenderingHints;

import java.awt.geom.AffineTransform;

import java.awt.image.BufferedImage;

import java.awt.image.ColorModel;

import java.awt.image.WritableRaster;

import java.io.File;

import javax.imageio.ImageIO;

public class Resize {

BufferedImage bufImage;

int width;

int height;

public Resize() {

// TODO Auto-generated constructor stub

}

public Resize(String srcPath,int width,int height) {

this.width = width;

this.height = height;

try{

this.bufImage = ImageIO.read(new File(srcPath));

}catch(Exception e){

e.printStackTrace();

}

}

public static BufferedImage rize(BufferedImage srcBufImage,int width,int height){

BufferedImage bufTarget = null;

double sx = (double) width / srcBufImage.getWidth();

double sy = (double) height / srcBufImage.getHeight();

int type = srcBufImage.getType();

if(type == BufferedImage.TYPE_CUSTOM){

ColorModel cm = srcBufImage.getColorModel();

WritableRaster raster = cm.createCompatibleWritableRaster(width,

height);

boolean alphaPremultiplied = cm.isAlphaPremultiplied();

bufTarget = new BufferedImage(cm, raster, alphaPremultiplied, null);

}else

bufTarget = new BufferedImage(width, height, type);

Graphics2D g = bufTarget.createGraphics();

g.setRenderingHint(RenderingHints.KEY_RENDERING,

RenderingHints.VALUE_RENDER_QUALITY);

g.drawRenderedImage(srcBufImage, AffineTransform.getScaleInstance(sx, sy));

g.dispose();

return bufTarget;

}

}

Q2: java如何实现图片拖动，放大缩小，旋转。

这个只是实现了移动，你参考以下吧 ！

public class MoveImage {

static int x,y;

private static int num=0;

private static Icon icon=null;

public static void main(String[] args) throws Exception{

JFrame f = new JFrame();

f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

f.getContentPane().setLayout(null);//这个要设置成 null

//图片

icon = new ImageIcon("d:/test.gif");//d:/test.gif本地一张图片

JLabel l = new JLabel(icon); //创建具有指定图像的 JLabel 实例。

l.setSize(icon.getIconWidth(),icon.getIconHeight());//设置面板的宽度和高度

l.setBorder(BorderFactory.createLineBorder(Color.red));//给图片加上红色外框

f.getContentPane().add(l);

f.setSize(900,700);

f.setVisible(true);

l.addMouseListener(new MouseAdapter(){

public void mousePressed(MouseEvent e){

x=e.getX();

y=e.getY();

}

});

l.addMouseMotionListener(new MouseMotionListener(){

public void mouseDragged(MouseEvent e) {

JLabel l = (JLabel)e.getSource();

l.setLocation(l.getX()+e.getX()-x,l.getY()+e.getY()-y);

}

public void mouseMoved(MouseEvent e) {}

});

}

Q3: 如何用Java实现图形的放大和缩小

java实现图形的放大和缩小java绘图缩放代码大全，其实就是在画图时java绘图缩放代码大全，改变图片的长和宽。以下代码参考一下java绘图缩放代码大全：

import java.awt.Graphics;

import java.awt.MouseInfo;

import java.awt.Point;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.MouseEvent;

import java.awt.event.MouseListener;

import java.io.File;

import javax.swing.ImageIcon;

import javax.swing.JButton;

import javax.swing.JFileChooser;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.filechooser.FileNameExtensionFilter;

public class App extends JFrame implements MouseListener, ActionListener {

int x = 0;

int y = 0;

File[] selectedFiles = null;

int fileIndex = 0;

int width = 200;

int height = 200;

public App() {

setDefaultCloseOperation(EXIT_ON_CLOSE);

setLocationRelativeTo(null);

setSize(400, 300);

setResizable(false);

getContentPane().setLayout(null);

JPanel panel = new ImagePanel();

panel.setBounds(12, 40, 370, 218);

getContentPane().add(panel);

addMouseListener(this);

JButton btnBrowse = new JButton("Browse");

btnBrowse.addActionListener(this);

btnBrowse.setBounds(12, 9, 91, 21);

getContentPane().add(btnBrowse);

setVisible(true);

}

public static void main(String[] args) {

new App();

}

public void actionPerformed(ActionEvent e) {

JFileChooser chooser = new JFileChooser();

chooser.setMultiSelectionEnabled(true);

FileNameExtensionFilter filter = new FileNameExtensionFilter(

"JPG  GIF Images", "jpg", "gif");

// 设置文件类型

chooser.setFileFilter(filter);

// 打开选择器面板

int returnVal = chooser.showOpenDialog(this);

if (returnVal == JFileChooser.APPROVE_OPTION) {

selectedFiles = chooser.getSelectedFiles();

repaint();

}

}

public void mouseClicked(MouseEvent e) {

}

public void mouseEntered(MouseEvent e) {

}

public void mouseExited(MouseEvent e) {

}

public void mousePressed(MouseEvent e) {

Point point = MouseInfo.getPointerInfo().getLocation();

x = point.x;

y = point.y;

}

public void mouseReleased(MouseEvent e) {

Point point = MouseInfo.getPointerInfo().getLocation();

int thisX = point.x;

int thisY = point.y;

System.out.println("thisX=" + thisX + "  " + "thisY=" + thisY);

if ((y - thisY  20  y - thisY  0)

|| (y - thisY  0  y - thisY  -20)) {

// Y 在20范围内移动认为是水平移动

if (x  thisX) {

// right

if (selectedFiles != null

 fileIndex  selectedFiles.length - 1) {

fileIndex++;

}

} else {

// left

if (selectedFiles != null  fileIndex  0) {

fileIndex--;

}

}

} else {

if (x  thisX) {

// 右下

width += 20;

height += 20;

} else {

// 左上

width -= 20;

height -= 20;

}

}

repaint();

}

class ImagePanel extends JPanel {

public void paint(Graphics g) {

super.paint(g);

if (selectedFiles != null) {

ImageIcon icon = new ImageIcon(selectedFiles[fileIndex]

.getPath());

g.drawImage(icon.getImage(), 0, 0, width, height, this);

}

}

}

}

Q4: 求java编程实现一个正方形放大缩小的代码

package bdzhidao;

import java.awt.*;

import javax.swing.*;

public class Square extends JFrame{

public static void main(String[] args){

JFrame frame=new JFrame("可变正方形");

Spanel jp=new Spanel();

frame.add(jp);

frame.setSize(1366,768);

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

frame.setResizable(true);

frame.setLocation(0,0);

frame.setVisible(true);

}

}

class Spanel extends JPanel{

int x=640;

int Width=8;

protected void paintComponent(Graphics g){

super.paintComponent(g);

g.setColor(new Color(10,200,40));

try{

Thread.sleep(1000);

}catch(InterruptedException e){

}

g.drawRect(x-=20,x-=20,Width+=10,Width+=10);

if(x=0){

System.exit(0);//当正方形移到屏幕里面时关闭程序java绘图缩放代码大全，如果没有该语句则最后屏幕会变成绿色

}

repaint();

}

}

//缩小就只需要把相关数据更改一下就OKjava绘图缩放代码大全了java绘图缩放代码大全，希望对java绘图缩放代码大全你有帮助!

//其实就是利用线程不断重新画图

Q5: java小程序图片查看器代码，实现放大、缩小、旋转功能

我只实现了放大缩小功能，旋转还有点问题package com.lzw;import java.awt.BorderLayout;

import java.awt.Canvas;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.Image;

import java.awt.Toolkit;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.net.URL;import javax.swing.ImageIcon;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.JScrollPane;

import javax.swing.JSlider;

import javax.swing.event.ChangeEvent;

import javax.swing.event.ChangeListener;

/*

* @功能：实现图片的放大缩小与旋转功能

* @日期：2011.6.29

*/

public class OperationOnPic extends JFrame{

private JPanel imageJpanel;

private JPanel southJpanel;

private JButton rorateButton;

private Mycanvas canvas ;

private int imgWidth, imgHeight;

private JSlider jSlide; //滑动块组建

// private JScrollPane jScrollPane ;

Image img;

private static int num=0;

private static int newWidth=0;

private static int newHeigth=0;

public static boolean isroate=false;

public OperationOnPic(){

setTitle("图片操作");

//设置窗体大小

setSize(800, 600);

//设置窗体显示在中央位置

setLocationRelativeTo(null);

//URL imgUrl = OperationOnPic.class.getResource("2.jpg"); //获得图片路径

//img = Toolkit.getDefaultToolkit().getImage(imgUrl);// 获取图片资源

ImageIcon image=new ImageIcon(OperationOnPic.class.getResource("2.jpg"));

img=image.getImage();

canvas=new Mycanvas();

//调用布局方法

init();

//设置窗体可见

setVisible(true);

}

public void init(){

setDefaultCloseOperation(this.EXIT_ON_CLOSE); //设置窗体可关闭

imageJpanel=new JPanel();

southJpanel=new JPanel();

imageJpanel.setLayout(new BorderLayout());

imageJpanel.add(canvas,BorderLayout.CENTER);

imageJpanel.add(getJSlider(),BorderLayout.SOUTH);

rorateButton=new JButton("图片旋转");

rorateButton.addActionListener(new ActionListener(){ public void actionPerformed(ActionEvent e) {

// TODO Auto-generated method stub

num+=5;

isroate=true;

canvas.repaint();

isroate=false;

}

});

southJpanel.add(rorateButton); //将按钮添加到面板上

this.getContentPane().add(imageJpanel,BorderLayout.CENTER);

this.getContentPane().add(southJpanel,BorderLayout.SOUTH);

}

public JSlider getJSlider(){

if(jSlide==null){

jSlide=new JSlider(); //实例化一个滑动块对象

jSlide.setMaximum(500); //设置滑动块的最大取值

jSlide.setMinimum(1); //设置滑动块的最小取值

jSlide.setValue(50); //设置滑动块当前值

jSlide.addChangeListener(new ChangeListener(){ public void stateChanged(ChangeEvent e) {

// TODO Auto-generated method stub

canvas.repaint(); //重新绘制图像

}

});

}

return jSlide;

}

public static void main(String[] args) {

new OperationOnPic();

}

class Mycanvas extends Canvas{

public void paint(final Graphics g){ //重写paint

if(isroate==false){

imgWidth=img.getWidth(this);

imgHeight=img.getHeight(this);

float value=jSlide.getValue(); //取得滑动块的值

newWidth=(int)(imgWidth*value/100);

newHeigth=(int)(imgHeight*value/100);

g.drawImage(img,0,0,newWidth,newHeigth,this);

g.dispose();

}else{

num+=5;

Graphics2D g2=(Graphics2D)g;

g2.rotate(Math.toRadians(num));

g2.drawImage(img,0,0,400,400,this);

g.dispose();

}

}

}

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