How can I save a region of an image into another image?

Question

How can I save a region of an image into another image? Should I use JAI?
Java2d? Is there an example?
Thank you.

Answer 1

Here is what I try, but I find out I just get a black square for my output image, can you please tell me what am I missing?
          ImageIcon file=new ImageIcon("images/clouds.jpg"); // You can't open bmp files
               // width, height looks correct:
               System.out.println (" width" + file.getIconWidth());
               System.out.println (" height" + file.getIconHeight());
               BufferedImage bi = new BufferedImage(file.getIconWidth(), file.getIconHeight(),
               BufferedImage.TYPE_INT_RGB);
               int x = 0;
               int y = 0;
               BufferedImage subimage = bi.getSubimage(x, y, 40, 40);
               File outputFile = new File("newimage.png");
               ImageIO.write(subimage, "png", outputFile);