package cn.byref.demo.image;import java.awt.Rectangle;import java.awt.image.BufferedImage;import java.io.File;import java.io.IOException;import java.util.Iterator;import javax.imageio.ImageIO;import javax.imageio.ImageReadParam;import javax.imageio.ImageReader;import javax.imageio.stream.ImageInputStream;import org.junit.Test;public class ImageDemo {    @Test    public void test_cut_image() throws IOException {        String imgPath = "C:\\Users\\GJ\\Desktop\\1.jpg";        String subPath = "C:\\Users\\GJ\\Desktop\\2.jpg";        File f = new File(imgPath);        File t = new File(subPath);        if (t.exists()) {            t.delete();        }                //图片输入流        ImageInputStream iis = ImageIO.createImageInputStream(f);                //图片读取器        Iterator
     
       it = ImageIO.getImageReaders(iis);                if (it.hasNext()) {            ImageReader r = it.next();                        //设置输入流            r.setInput(iis, true);            System.out.println("格式=" + r.getFormatName());            System.out.println("宽=" + r.getWidth(0));            System.out.println("高=" + r.getHeight(0));                        //读取参数            ImageReadParam param = r.getDefaultReadParam();                        //创建要截取的矩形范围            Rectangle rect = new Rectangle(100, 100, 400, 200);                        //设置截取范围参数            param.setSourceRegion(rect);                        //读取截图数据            BufferedImage bi = r.read(0, param);            // 保存图片            ImageIO.write(bi, "jpg", t);        }    }}