package com.cxf.dao;

import java.awt.Graphics2D;

import java.awt.Image;

import java.awt.image.BufferedImage;

import java.io.ByteArrayOutputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.InputStream;

import javax.imageio.ImageIO;

import javax.swing.ImageIcon;

public class Alpha {

    public static void main(String[] args) {

        transferAlpha();

    }

public static byte[] transferAlpha() {

   ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();

   File file = new File("E:/07.png");

   InputStream is;

   try {

    is = new FileInputStream(file);
　　//如果是MultipartFile类型，那么自身也有转换成流的方法：is = file.getInputStream();

    BufferedImage bi=ImageIO.read(is);

    Image image=(Image)bi;

    ImageIcon imageIcon = new ImageIcon(image);

    BufferedImage bufferedImage = new BufferedImage(imageIcon

      .getIconWidth(), imageIcon.getIconHeight(),

      BufferedImage.TYPE_4BYTE_ABGR);

    Graphics2D g2D = (Graphics2D) bufferedImage.getGraphics();

    g2D.drawImage(imageIcon.getImage(), 0, 0, imageIcon

      .getImageObserver());

    int alpha = 0;

    for (int j1 = bufferedImage.getMinY(); j1 < bufferedImage

      .getHeight(); j1++) {

     for (int j2 = bufferedImage.getMinX(); j2 < bufferedImage

       .getWidth(); j2++) {

      int rgb = bufferedImage.getRGB(j2, j1);

      int R =(rgb & 0xff0000 ) >> 16 ;

      int G= (rgb & 0xff00 ) >> 8 ;

      int B= (rgb & 0xff );

      if(((255-R)<30) && ((255-G)<30) && ((255-B)<30)){

       rgb = ((alpha + 1) << 24) | (rgb & 0x00ffffff);

      }

      bufferedImage.setRGB(j2, j1, rgb);

     }

    }

    g2D.drawImage(bufferedImage, 0, 0, imageIcon.getImageObserver());

    ImageIO.write(bufferedImage, "png", new File("e:/67.png"));//直接输出文件

   // ImageIO.write(bufferedImage, "png", byteArrayOutputStream);//转换成byte数组

   } catch (Exception e) {

       e.printStackTrace();

   }finally{

   }

   return byteArrayOutputStream.toByteArray();

}

}