① 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。怎么用java代码放大或缩小图片不失真。
② 相册管理 java实现 功能是图片显示与图片放大缩小 急~~
上楼的我只想说你根本不懂java，这么简单的功能都不能实现，还是一门编程语言吗？ 一、部分截图： ①打开 ②放大 ③翻转 ④缩小 二、源程序： import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.File;
public class PhotoFrame extends JFrame implements ActionListener{ Canvas photo;
JPanel p;
JButton open,bigger,smaller,rotate,exit;
JScrollPane sp;
JFileChooser fc;
int w = 150;
int h = 150;
Image image;
int rate = 10;//图片放缩率（单位：像素）
public PhotoFrame(){
init();
this.setTitle ("Java图片查看器");
this.setSize (600,500);
this.setLocationRelativeTo (this);//窗口居中
this.setVisible (true);
this.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
}
public void init(){
photo = new Photo();
sp = new JScrollPane(photo);
p = new JPanel();
open = new JButton("open");
bigger = new JButton(" ＋ ");
smaller = new JButton(" － ");
rotate = new JButton(" の ");
exit = new JButton("exit");
//设置前景色
open.setForeground (Color.BLUE);
bigger.setForeground (Color.GREEN);
smaller.setForeground (Color.GREEN);
rotate.setForeground (Color.GREEN);
exit.setForeground (Color.RED);
//设置提示文本
open.setToolTipText ("打开文件");
bigger.setToolTipText ("放大");
smaller.setToolTipText ("缩小");
rotate.setToolTipText ("翻转");
exit.setToolTipText ("退出程序");
//设置边框
p.setBorder (BorderFactory.createEtchedBorder ());
p.add (open);
p.add (bigger);
p.add (smaller);
p.add (rotate);
p.add (exit);
add(sp,BorderLayout.CENTER);
add(p,BorderLayout.SOUTH);
open.addActionListener (this);
bigger.addActionListener (this);
smaller.addActionListener (this);
rotate.addActionListener (this);
exit.addActionListener (this);
}
public static void main(String[] args){
new PhotoFrame();
} public void actionPerformed (ActionEvent e){
if(e.getSource ()==open){//打开
fc = new JFileChooser();
int returnval = fc.showOpenDialog(this);
if(returnval == JFileChooser.APPROVE_OPTION){
File f = fc.getSelectedFile ();
String fileName = f.getName ();
String filePath=fc.getSelectedFile().getAbsolutePath();
System.out.println(filePath);
this.setTitle (fileName+"-Java图片查看器");
//通过文件路径获得图片
image = new ImageIcon(filePath).getImage ();
//获取图片的宽和高
w = image.getWidth (this);
h = image.getHeight (this);
}
}else if(e.getSource ()==bigger){//放大
if(w>0) w+= rate;
else w-= rate;
if(h>0)h+= rate;
else h-= rate;
}else if(e.getSource ()==smaller){//缩小
if(w>0) w-= rate;
else w+= rate;
if(h>0) h-= rate;
else h+= rate;
}else if(e.getSource ()==rotate){//翻转
if(w>0&&h>0){
h*=-1;
}else if(w>0&&h<0){
w*=-1;
}else if(w<0&&h<0){
h*=-1;
}else if(w<0&&h>0){
w*=-1;
}
}else{//退出
System.exit(0);
}
photo.repaint ();//重新绘制
}
class Photo extends Canvas{
public void paint(Graphics g){
int width = this.getWidth();
int height = this.getHeight();
//设置图片左上角坐标
int x = (width-w)/2;
int y = (height-h)/2;
//绘制图片
g.drawImage(image, x, y, w, h,this);
}
}
}
三、补充：1、滚动面板功能没有具体实现2、放大缩小率应该按照图片宽高比来设置，最好用一个滚动条来放大缩小3、翻转功能需要改进 楼主自己试着完善下...
③ 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，其实就是在画图时，改变图片的长和宽。以下代码参考一下：
importjava.awt.Graphics;
importjava.awt.MouseInfo;
importjava.awt.Point;
importjava.awt.event.ActionEvent;
importjava.awt.event.ActionListener;
importjava.awt.event.MouseEvent;
importjava.awt.event.MouseListener;
importjava.io.File;
importjavax.swing.ImageIcon;
importjavax.swing.JButton;
importjavax.swing.JFileChooser;
importjavax.swing.JFrame;
importjavax.swing.JPanel;
importjavax.swing.filechooser.FileNameExtensionFilter;
,ActionListener{
intx=0;
inty=0;
File[]selectedFiles=null;
intfileIndex=0;
intwidth=200;
intheight=200;
publicApp(){
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setSize(400,300);
setResizable(false);
getContentPane().setLayout(null);
JPanelpanel=newImagePanel();
panel.setBounds(12,40,370,218);
getContentPane().add(panel);
addMouseListener(this);
JButtonbtnBrowse=newJButton("Browse");
btnBrowse.addActionListener(this);
btnBrowse.setBounds(12,9,91,21);
getContentPane().add(btnBrowse);
setVisible(true);
}
publicstaticvoidmain(String[]args){
newApp();
}
publicvoidactionPerformed(ActionEvente){
JFileChooserchooser=newJFileChooser();
chooser.setMultiSelectionEnabled(true);
FileNameExtensionFilterfilter=newFileNameExtensionFilter(
"JPG&GIFImages","jpg","gif");
//设置文件类型
chooser.setFileFilter(filter);
//打开选择器面板
intreturnVal=chooser.showOpenDialog(this);
if(returnVal==JFileChooser.APPROVE_OPTION){
selectedFiles=chooser.getSelectedFiles();
repaint();
}
}
publicvoidmouseClicked(MouseEvente){
}
publicvoidmouseEntered(MouseEvente){
}
publicvoidmouseExited(MouseEvente){
}
publicvoidmousePressed(MouseEvente){
Pointpoint=MouseInfo.getPointerInfo().getLocation();
x=point.x;
y=point.y;
}
publicvoidmouseReleased(MouseEvente){
Pointpoint=MouseInfo.getPointerInfo().getLocation();
intthisX=point.x;
intthisY=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();
}
classImagePanelextendsJPanel{
publicvoidpaint(Graphicsg){
super.paint(g);
if(selectedFiles!=null){
ImageIconicon=newImageIcon(selectedFiles[fileIndex]
.getPath());
g.drawImage(icon.getImage(),0,0,width,height,this);
}
}
}
}