android图像处理之灰度化

package com.scy.grayvalue2;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.util.Log;
import android.view.Menu;
import android.widget.ImageView;

/**
 * 思路如下：
 
     1.读取or照相，得到一张ARGB图片。
 
     2.转化为bitmap类，并对其数据做如下操作：
 
        A通道保持不变，然后逐像素计算：X = 0.3×R+0.59×G+0.11×B，并使这个像素的值新R，G，B值为X，即：
 
        new_R = X, new_G = X, new_B = X
 
        例如：原来一个像素是4个byte，分别为ARGB，现在这个像素应该为AXXX。
 
      3.将上一步骤得到的bitmap图像写到输出流里面，并保存为图片。或者直接显示在ImageView上。

 * @author scy
 *
 */
public class MainActivity extends Activity 
{
	private byte[] rawData;
	private ImageView imageView;
	
    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        imageView = (ImageView)findViewById(R.id.image);
        //将bitmap转换成一个伪灰度图，再转化成一个byte[]
        //将byte[]转换为bitmap
//		Bitmap bitmapOrg = BitmapFactory.decodeByteArray(rawData, 0, rawData.length);
        Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
		Bitmap bitmapNew = bitmapOrg.copy(Config.ARGB_8888, true); 
		//Bitmap bitmapNew = bitmapOrg.copy(Config.ARGB_8888, true);
		if(bitmapNew == null)
			Log.i("TAG", "null");
		Log.i("TAG", "copy end");
		/**
		 * 一种简单的灰度化算法，但是这种方法需要修改每个点的像素，如果一张图片比较大，则这个处理速度就堪忧了
		 * 往往需要创建一个线程来处理
		 */
        for(int i = 0;i<bitmapNew.getWidth();i++)
        {
      	  for(int j =0;j<bitmapNew.getHeight();j++)
      	  {	
                int col = bitmapNew.getPixel(i, j);//获取点（i，j）处的像素
                //分别获取ARGB的值
                int alpha = col&0xFF000000;
                int red = (col&0x00FF0000)>>16;
                int green = (col&0x0000FF00)>>8;
                int blue = (col&0x000000FF);
                //用公式X = 0.3×R+0.59×G+0.11×B计算出X代替原来的RGB
                int gray = (int)((float)red*0.3+(float)green*0.59+(float)blue*0.11);
                //新的ARGB
                int newColor = alpha|(gray<<16)|(gray<<8)|gray;
                //在点（i,j）处设置新的像素
                bitmapNew.setPixel(i, j, newColor);
                //Log.v("tag",  Integer.toHexString(col));  
      	  }
        }
        Log.i("TAG", "pro end");
        sendMsg(bitmapNew);
        /*
        File file = new File(Environment.getExternalStorageDirectory()+File.separator+"gray"+number+".jpg");
        OutputStream out;
		try {
			out = new FileOutputStream(file);
			if(bitmapNew.compress(Bitmap.CompressFormat.JPEG, 100, out))
				Log.i("TAG", "success");
			out.close();
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} 
		*/
	}

	private void sendMsg(Bitmap bitmapNew)
	{
		imageView.setImageBitmap(bitmapNew);
	}
}

/**
 * drawableToBitmap
 */
/*
 public static Bitmap drawableToBitmap(Drawable drawable) {
        
        Bitmap bitmap = Bitmap
                        .createBitmap(
                                        drawable.getIntrinsicWidth(),
                                        drawable.getIntrinsicHeight(),
                                        drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
                                                        : Bitmap.Config.RGB_565);
        Canvas canvas = new Canvas(bitmap);
        //canvas.setBitmap(bitmap);
        drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
        drawable.draw(canvas);
        return bitmap;
}
 */

/**
 * Bitmap2Bytes
 */
/*
 private byte[] Bitmap2Bytes(Bitmap bm)
 {
	ByteArrayOutputStream baos = new ByteArrayOutputStream(); 
	bm.compress(Bitmap.CompressFormat.PNG, 100, baos); 
 	return baos.toByteArray();
 }
*/

/**
 * Bytes2Bimap
 */
/*
 private Bitmap Bytes2Bimap(byte[] b)
 {
    if(b.length ==0)
    {
    	return null;
    }

	return BitmapFactory.decodeByteArray(b, 0, b.length);

  }
*/
package com.scy.grayvalue2;

import java.io.Fil