如何在Java中实现图片裁剪？

下面是我的一段代码，实现如何截取图片的：

// 图片源

private static final String SRC_FILE="org//zy//demo//jdk//base//image//car1.jpg";

// 目标图片

private static final String DEST_FILE="c://a.jpg";

/**

* 读取图像文件

* 用 ImageReader

* @param imgPath

* @throws IOException

*/

public void readUsingImageReader(String imgPath) throws IOException{

// 取得图片读入器

Iterator readers = ImageIO.getImageReadersByFormatName("jpg");

System.out.println(readers);

ImageReader reader = (ImageReader)readers.next();

System.out.println(reader);

// 取得图片读入流

InputStream source=this.parseImagePath(ImageDemo.SRC_FILE);

ImageInputStream iis = ImageIO.createImageInputStream(source);

reader.setInput(iis, true);

// 图片参数

ImageReadParam param = reader.getDefaultReadParam();

int imageIndex = 0;

int half_width = reader.getWidth(imageIndex)/2;

int half_height = reader.getHeight(imageIndex)/2;

// Rectangle rect = new Rectangle(60, 60, half_width, half_height);

Rectangle rect = new Rectangle(60, 60, 100, 100);

param.setSourceRegion(rect);

BufferedImage bi = reader.read(0,param);

ImageIO.write(bi, "jpg", this.initDestFile());

}