实现思路：
在原图(image)上虚构一个长度可以伸缩的正方框，将框出来的图像切割出来作为子图(tempImage1)，子图1:1放大或缩小到要显示的大小，对子图重缩放(tempImage2)，子图上再切割出图像作为要保存的图像(saveImage)；最后显示的图像是tempImage2和覆盖在上面的saveImage。
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package Body;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.image.BufferedImage;
import java.awt.image.RescaleOp;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
/**
*
* @author 心里的潇洒情
*/
public class CutHeadImage extends JFrame{
private BufferedImage image;//原图
private BufferedImage tempImage1;//子图
private BufferedImage tempImage2;//重缩放子图
private BufferedImage saveImage;
private final int lenght=700;//显示大小700*700，包括2*padding
private final int padding=100;
private final int margin=100;//制作原图留的外边距
private int nowSize;//虚构方框大小
private final int minSize,maxSize;//虚构方框大小边界，规范nowSize
private JPanel toolPane;
private int orgx,orgy,endx,endy;
private int lux=0,luy=0;//虚构方框左上角
public CutHeadImage(Image i){
setLayout(null);
setUndecorated(true);
setDefaultCloseOperation(javax.swing.WindowConstants.HIDE_ON_CLOSE);
setBackground(new java.awt.Color(255, 102, 51));
setCursor(new java.awt.Cursor(java.awt.Cursor.HAND_CURSOR));
setResizable(false);
setTitle("调整图片");
toolPane=new JPanel();
toolPane.setBackground(Color.gray);
toolPane.setLayout(new FlowLayout());
JButton yesButton=new JButton("确定");
yesButton.addMouseListener(new java.awt.event.MouseAdapter() {
});
JButton cancleButton=new JButton("取消");
cancleButton.addMouseListener(new java.awt.event.MouseAdapter(){
@Override
public void mouseClicked(MouseEvent evt){
dispose();
}
});
toolPane.add(yesButton);
toolPane.add(cancleButton);
this.add(toolPane);
toolPane.setBounds(0,lenght,lenght, 100);
setSize(lenght, lenght+100);
int x = (Toolkit.getDefaultToolkit().getScreenSize().width - this.getSize().width)/2;
int y = (Toolkit.getDefaultToolkit().getScreenSize().height - this.getSize().height)/2;
setLocation(x, y);
this.setVisible(true);
int smaller=Math.min(i.getWidth(null), i.getHeight(null));
double N=(lenght-2.0*padding)/smaller;
int width=(int)(i.getWidth(null)*N);
int height=(int)(i.getHeight(null)*N);
BufferedImage temp=new BufferedImage(2*margin+width, 2*margin+height, BufferedImage.TYPE_INT_BGR);
Graphics2D bGr = temp.createGraphics();
bGr.setColor(Color.white);
bGr.fillRect(0, 0, 2*margin+width,2*margin+width);
bGr.drawImage(i, margin, margin, width, height, null);
bGr.dispose();
image=temp;
nowSize=Math.min(image.getWidth(), image.getHeight());
maxSize=nowSize;
minSize=maxSize-200;
addMouseWheelListener(new MouseWheelListener() {
public void mouseWheelMoved(MouseWheelEvent evt) {
int n=evt.getWheelRotation();
if(nowSize==minSize&&n<0)
return ;
else if(nowSize==maxSize&&n>0)
return ;
nowSize+=n*10;
lux+=n*5;
luy+=n*5;
if(nowSize>=maxSize)
nowSize=maxSize;
else if(nowSize<=minSize)
nowSize=minSize;
if(lux<=0)
lux=0;
else if(lux+nowSize>=image.getWidth())
lux=image.getWidth()-nowSize;
if(luy<=0)
luy=0;
else if(luy+nowSize>=image.getHeight())
luy=image.getHeight()-nowSize;
make();
}
});
addMouseListener(new MouseAdapter(){
@Override
public void mousePressed(MouseEvent e) {
orgx=e.getX();
orgy=e.getY();
}
});
addMouseMotionListener(new MouseMotionAdapter(){
@Override
public void mouseDragged(MouseEvent e){
endx=e.getX();
endy=e.getY();
lux=lux-(endx-orgx);
luy=luy-(endy-orgy);
if(lux<=0)
lux=0;
else if(lux+nowSize>=image.getWidth())
lux=image.getWidth()-nowSize;
if(luy<=0)
luy=0;
else if(luy+nowSize>=image.getHeight())
luy=image.getHeight()-nowSize;
make();
}
});
}
protected void make(){
BufferedImage temp=new BufferedImage(lenght, lenght ,BufferedImage.TYPE_INT_BGR);
temp.createGraphics().drawImage(image.getSubimage(lux, luy, nowSize, nowSize), 0, 0, lenght,lenght,null);//切割后放大或缩小
tempImage1=temp;
RescaleOp ro = new RescaleOp(0.8f, 0, null);
tempImage2 = ro.filter(tempImage1, null);
Image tempImage3=createImage(lenght,lenght);//margin+lenght+margin,margin为空
Graphics g=tempImage3.getGraphics();
g.drawImage(tempImage2, 0, 0, lenght,lenght,null);
g.setColor(Color.green);
g.drawRect(padding-1, padding-1, lenght-2*padding+1, lenght-2*padding+1);
saveImage=tempImage1.getSubimage(padding, padding, lenght-2*padding, lenght-2*padding);
g.drawImage(saveImage, padding, padding, null);
CutHeadImage.this.getGraphics().drawImage( tempImage3, 0, 0, null);
}
@Override
public void paint(Graphics g){
super.paint(g);
BufferedImage temp=new BufferedImage(lenght, lenght ,BufferedImage.TYPE_INT_BGR);
temp.createGraphics().drawImage(image.getSubimage(lux, luy, nowSize, nowSize), 0, 0, lenght,lenght,null); ;
tempImage1=temp;
RescaleOp ro = new RescaleOp(0.8f, 0, null);
tempImage2 = ro.filter(tempImage1, null);
g.drawImage(tempImage2, 0, 0, lenght, lenght, null);
g.setColor(Color.green);
g.drawRect(padding-1, padding-1, lenght-2*padding+1, lenght-2*padding+1);//99,99,501,501
saveImage=tempImage1.getSubimage(padding, padding, lenght-2*padding, lenght-2*padding);
g.drawImage(saveImage, padding, padding, null);
}
public static void main(String args[]){
new CutHeadImage(new ImageIcon("C:\\Users\\心里的潇洒情\\Desktop\\新建文件夹\\0c3c28bfd9fbe87b952ce334fd430ae.jpg").getImage());
}
}