Android-将RGB彩色图转换为灰度图

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)*/@Overridepublic 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() {@Overridepublic 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 << 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/imageView1"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_gravity="center_horizontal"/><Button android:id="@+id/rgb2greybtn"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="@string/rgb2greybtn"android:layout_gravity="center_horizontal"/><ImageView android:id="@+id/imageView2"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_gravity="center_horizontal"/>"
</LinearLayout>