java實現圖片裁剪縮放工具類

import java.awt.Image;

import java.awt.Rectangle;

import java.awt.geom.AffineTransform;

import java.awt.image.AffineTransformOp;

import java.awt.image.BufferedImage;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.util.Iterator;

import javax.imageio.ImageIO;

import javax.imageio.ImageReadParam;

import javax.imageio.ImageReader;

import javax.imageio.stream.ImageInputStream;
public class ImageHelper {

    /*

 * 根據尺寸圖片居中裁剪 
 */  
 public static void cutCenterImage(String src,String dest,int w,int h) throws IOException{   
     Iterator iterator = ImageIO.getImageReadersByFormatName("jpg");   
     ImageReader reader = (ImageReader)iterator.next();   
     InputStream in=new FileInputStream(src);  
     ImageInputStream iis = ImageIO.createImageInputStream(in);   
     reader.setInput(iis, true);   
     ImageReadParam param = reader.getDefaultReadParam();   
     int imageIndex = 0;   
     Rectangle rect = new Rectangle((reader.getWidth(imageIndex)-w)/2, (reader.getHeight(imageIndex)-h)/2, w, h);    
     param.setSourceRegion(rect);   
     BufferedImage bi = reader.read(0,param);     
     ImageIO.write(bi, "jpg", new File(dest));             

 }  
/* 
 * 圖片裁剪二分之一 
 */  
 public static void cutHalfImage(String src,String dest) throws IOException{   
     Iterator iterator = ImageIO.getImageReadersByFormatName("jpg");   
     ImageReader reader = (ImageReader)iterator.next();   
     InputStream in=new FileInputStream(src);  
     ImageInputStream iis = ImageIO.createImageInputStream(in);   
     reader.setInput(iis, true);   
     ImageReadParam param = reader.getDefaultReadParam();   
     int imageIndex = 0;   
     int width = reader.getWidth(imageIndex)/2;   
     int height = reader.getHeight(imageIndex)/2;   
     Rectangle rect = new Rectangle(width/2, height/2, width, height);   
     param.setSourceRegion(rect);   
     BufferedImage bi = reader.read(0,param);     
     ImageIO.write(bi, "jpg", new File(dest));     
 }  
/* 
 * 圖片裁剪通用接口 
 */  

public static void cutImage(String src,String dest,int x,int y,int w,int h) throws IOException{   
       Iterator iterator = ImageIO.getImageReadersByFormatName("jpg");   
       ImageReader reader = (ImageReader)iterator.next();   
       InputStream in=new FileInputStream(src);  
       ImageInputStream iis = ImageIO.createImageInputStream(in);   
       reader.setInput(iis, true);   
       ImageReadParam param = reader.getDefaultReadParam();   
       Rectangle rect = new Rectangle(x, y, w,h);    
       param.setSourceRegion(rect);   
       BufferedImage bi = reader.read(0,param);     
       ImageIO.write(bi, "jpg", new File(dest));             

}   
/* 
 * 圖片縮放 
 */  
public static void zoomImage(String src,String dest,int w,int h) throws Exception {  
    double wr=0,hr=0;  
    File srcFile = new File(src);  
    File destFile = new File(dest);  
    BufferedImage bufImg = ImageIO.read(srcFile);  
    Image Itemp = bufImg.getScaledInstance(w, h, bufImg.SCALE_SMOOTH);  
    wr=w*1.0/bufImg.getWidth();  
    hr=h*1.0 / bufImg.getHeight();  
    AffineTransformOp ato = new AffineTransformOp(AffineTransform.getScaleInstance(wr, hr), null);  
    Itemp = ato.filter(bufImg, null);  
    try {  
        ImageIO.write((BufferedImage) Itemp,dest.substring(dest.lastIndexOf(".")+1), destFile);  
    } catch (Exception ex) {  
        ex.printStackTrace();  
    }  

}  

}  </pre>