Android-将RGB彩×××转换为灰度图

Android-将RGB彩×××转换为灰度

实例：RGB2Grey

项目运行效果图：

源代码：

public class MainActivity extends Activity { 

        /* (non-Javadoc) 
         * @see android.app.Activity#onCreate(android.os.Bundle) 
         */ 
        @Override 
        public void onCreate(Bundle savedInstanceState) { 
                super.onCreate(savedInstanceState); 
                setContentView(R.layout.activity_main); 
                //通过Id来获取界面中组件的引用 
                Button rgb2greyBtn    = (Button) findViewById(R.id.rgb2greybtn); 
                ImageView p_w_picpathView1 = (ImageView) findViewById(R.id.p_w_picpathView1); 
                final ImageView p_w_picpathView2 = (ImageView) findViewById(R.id.p_w_picpathView2);    
                //通过位图工厂，创建一个位图 
                final Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_android); 
                p_w_picpathView1.setImageBitmap(bitmap); 
                //为“转换为灰度图”按钮添加监听事件 
                rgb2greyBtn.setOnClickListener(new OnClickListener() { 
        
      @Override 
      public void onClick(View v) { 
        // TODO Auto-generated method stub 
        //将转换过后的灰度图显示出来 
        p_w_picpathView2.setImageBitmap(convertGreyImg(bitmap)); 
      } 
    }); 
                 
        } 
         
        /** 
         * 将彩×××转换为灰度图 
         * @param img 位图 
         * @return  返回转换好的位图 
         */ 
        public Bitmap convertGreyImg(Bitmap img) { 
          int width = img.getWidth();      //获取位图的宽 
          int height = img.getHeight();    //获取位图的高 
            
          int []pixels = new int[width * height];  //通过位图的大小创建像素点数组 
            
          img.getPixels(pixels, 0, width, 0, 0, width, height); 
          int alpha = 0xFF << 24;    
          for(int i = 0; i < height; i++)  { 
            for(int j = 0; j < width; j++) { 
              int grey = pixels[width * i + j]; 
                
              int red = ((grey    & 0x00FF0000 ) >> 16); 
              int green = ((grey & 0x0000FF00) >> 8); 
              int blue = (grey & 0x000000FF); 
                
              grey = (int)((float) red * 0.3 + (float)green * 0.59 + (float)blue * 0.11); 
              grey = alpha | (grey << 16) | (grey << 8) | grey; 
              pixels[width * i + j] = grey; 
            } 
          } 
          Bitmap result = Bitmap.createBitmap(width, height, Config.RGB_565); 
          result.setPixels(pixels, 0, width, 0, 0, width, height); 
          return result; 
        } 
} 


       

布局文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

        xmlns:tools="http://schemas.android.com/tools"

        android:id="@+id/LinearLayout1"

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        android:orientation="vertical" >

  <ImageView    

         android:id="@+id/p_w_picpathView1"

         android:layout_width="wrap_content"

         android:layout_height="wrap_content"

         android:layout_gravity="center_horizontal"

         />

  <Button    

         android:id="@+id/rgb2greybtn"

         android:text="@string/rgb2greybtn"

         android:layout_gravity="center_horizontal"/>

         android:id="@+id/p_w_picpathView2"

         />"

</LinearLayout>