实例：RGB2Grey

项目运行效果图：       

源代码：

[java] 
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 imageView1 = (ImageView) findViewById(R.id.imageView1); 
        final ImageView imageView2 = (ImageView) findViewById(R.id.imageView2);  
        //通过位图工厂，创建一个位图  
        final Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_android); 
        imageView1.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  
                imageView2.setImageBitmap(convertGreyImg(bitmap)); 
            } 
        }); 

    } 

    /**
     * 将彩色图转换为灰度图
     * @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 > 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 > 8);
       int blue = (grey & 0x000000FF);

       grey = (int)((float) red * 0.3 + (float)green * 0.59 + (float)blue * 0.11);
       grey = alpha | (grey