public class GrayView extends View {    private Bitmap bmp;        public GrayView(Context context) {        super(context);        Resources res = getResources();        bmp    = BitmapFactory.decodeResource(res, R.drawable.ic_launcher);//将ic_launcher则个资源生成一个bitmap对象    }    @Override    protected void onDraw(Canvas canvas) {        // TODO Auto-generated method stub        Bitmap output = Bitmap.createBitmap(bmp.getWidth(),                 bmp.getHeight(),                 Config.ARGB_8888);//定义一个与原始bitmap一样大小的bitmap对象                for(int i = 0; i < bmp.getWidth(); i++){            for(int j = 0; j < bmp.getHeight(); j++){                                int color     = bmp.getPixel(i, j);//获取某一坐标的像素值                int red     = Color.red(color); //解析出R、G、B的值                int green     = Color.green(color);                int blue     = Color.blue(color);                                int tmp = (red + green + blue)/3; //转换成灰度值                                output.setPixel(i, j, Color.rgb(tmp,tmp,tmp)); //给相应坐标的像素点赋值R、G、B            }        }        canvas.drawBitmap(output, 100, 100, null);//将该bitmap绘制在canvas上    }}