JAVA中BufferedImage的用法

1.用到的包

public static void main(String[] args) {

    // TODO Auto-generated method stub

      int width = 100;

      int height = 100;

   // 1.创建一个不带透明色的BufferedImage对象

    BufferedImage bimage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

      // 2.创建一个带透明色的BufferedImage对象

     bimage = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);

    // 3.创建一个与屏幕相适应的BufferedImage对象

    GraphicsEnvironment ge = GraphicsEnvironment .getLocalGraphicsEnvironment();

     GraphicsDevice gs = ge.getDefaultScreenDevice();

     GraphicsConfiguration gc = gs.getDefaultConfiguration();

    // Create an image that does not support transparency

     bimage = gc.createCompatibleImage(width, height, Transparency.OPAQUE);

     // Create an image that supports transparent pixels

     bimage = gc.createCompatibleImage(width, height, Transparency.BITMASK);

      // Create an image that supports arbitrary levels of transparency

    bimage = gc.createCompatibleImage(width, height,

               Transparency.TRANSLUCENT);

  }

  // 4.当然我们也可以在图形上下文来创建一个BufferedImage对象

 public void paint(Graphics g) {

      Graphics2D g2d = (Graphics2D) g;

      int width = 100;

      int height = 100;

     // Create an image that does not support transparency

     BufferedImage bimage = g2d.getDeviceConfiguration()

                             .createCompatibleImage(width, height, Transparency.OPAQUE);

      // Create an image that supports transparent pixels

     bimage = g2d.getDeviceConfiguration().createCompatibleImage(width,

               height, Transparency.BITMASK);

     // Create an image that supports arbitrary levels of transparency

     bimage = g2d.getDeviceConfiguration().createCompatibleImage(width,

               height, Transparency.TRANSLUCENT);

  }

}

2.使用BufferedImage的图像剪裁：

public static void main(String[] args) {

  try {

  //从特定文件载入

  BufferedImage bi = ImageIO.read(new File("c:\\test.jpg"));

  bi.getSubimage(0, 0, 10, 10);

 } catch (IOException e) {

  e.printStackTrace();

 }


2.如何取到BufferedImage

BufferedImage image = ImageIO.read(new File("1.gif"));

3.BufferedImage  ---->byte[]
ImageIO.write(BufferedImage image,String format,OutputStream out);方法可以很好的解决问题；
参数image表示获得的BufferedImage；

参数format表示图片的格式，比如“gif”等；

参数out表示输出流，如果要转成Byte数组，则输出流为ByteArrayOutputStream即可；

执行完后，只需要toByteArray()就能得到byte[];
4.显示BufferedImage

public void paint(Graphics g){

   super.paint(g);

   g.drawImage(image);    //image为BufferedImage类型

}