BufferedImage学习记录一

一、BufferedImage是Image的一个子类，BufferedImage生成的图片在内存里有一个图像缓冲区，利用这个缓冲区我们可以很方便的操作这个图片，通常用来做图片修改操作如大小变换、图片变灰、设置图片透明或不透明等。

二、java创建BufferedImage对象：

导入包：

import java.awt.Frame;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.GraphicsConfiguration;

import java.awt.GraphicsDevice;

import java.awt.GraphicsEnvironment;

import java.awt.Transparency;

import java.awt.image.BufferedImage;


public class Test extends Frame{

    /**
    * @param args
    */
    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);
    }
}

三、获取图片：

BufferedImage bufferedImage = ImageIO.read(new FileInputStream(filePath));

如：

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