10032---java实现图片裁剪缩放工具类

package out;

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 {
/*
* 根据尺寸图片居中裁剪
*/
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));

}
/*
* 图片裁剪二分之一
*/
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));
}
/*
* 图片裁剪通用接口
*/

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));

}
/*
* 图片缩放
*/
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();
}

}
}