android face detection

MainActivity.java

package com.example.pineoc.facedetection;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.util.Log;
import android.util.SparseArray;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import com.google.android.gms.vision.Frame;
import com.google.android.gms.vision.face.Face;
import com.google.android.gms.vision.face.FaceDetector;
import com.google.android.gms.vision.face.Landmark;

import java.util.List;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button btn = (Button) findViewById(R.id.button);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                ImageView myImageView = (ImageView) findViewById(R.id.imgview);
                BitmapFactory.Options options = new BitmapFactory.Options();
                options.inMutable = true;
                Bitmap myBitmap = BitmapFactory.decodeResource(
                        getApplicationContext().getResources(),
                        R.drawable.test1,
                        options);

                //rect color paint
                Paint myRectPaint = new Paint();
                myRectPaint.setStrokeWidth(5);
                myRectPaint.setColor(Color.RED);
                myRectPaint.setStyle(Paint.Style.STROKE);
                //circle color paint
                Paint Pnt = new Paint();
                Pnt.setColor(Color.GREEN);
                Pnt.setStrokeWidth(5);
                Pnt.setStyle(Paint.Style.STROKE);

                Bitmap tempBitmap = Bitmap.createBitmap(myBitmap.getWidth(), myBitmap.getHeight(), Bitmap.Config.RGB_565);
                Canvas tempCanvas = new Canvas(tempBitmap);
                tempCanvas.drawBitmap(myBitmap, 0, 0, null);

                FaceDetector faceDetector = new FaceDetector.Builder(getApplicationContext())
                        .setTrackingEnabled(false)
                        .setLandmarkType(FaceDetector.ALL_LANDMARKS)
                        .build();
                if(!faceDetector.isOperational()){
                    new AlertDialog.Builder(v.getContext()).setMessage("couldn't set up the face detector!");
                    return;
                }

                Frame frame = new Frame.Builder().setBitmap(myBitmap).build();
                SparseArray<Face> faces = faceDetector.detect(frame);

                for(int i=0; i<faces.size(); i++){
                    Face thisFace = faces.valueAt(i);
                    float x1 = thisFace.getPosition().x;
                    float y1 = thisFace.getPosition().y;
                    float x2 = x1 + thisFace.getWidth();
                    float y2 = y1 + thisFace.getHeight();
                    tempCanvas.drawRoundRect(new RectF(x1,y1,x2,y2), 2, 2, myRectPaint);

                    //draw landmarks
                    List<Landmark> landmarks = thisFace.getLandmarks();
                    //for make landmark circle
                    for(int j=0; j<landmarks.size(); j++){
                        Landmark thisLand = landmarks.get(j);
                        float landx = thisLand.getPosition().x;
                        float landy = thisLand.getPosition().y;
                        tempCanvas.drawCircle(landx, landy, 10, Pnt);
                    }
                }
                myImageView.setImageDrawable(new BitmapDrawable(getResources(), tempBitmap));
                faceDetector.release();
            }
        });
    }
}

Hello :)
can you please help me with landmark detection, I just want to know how can i detect as for exemple " eiffel tower"
my code just detects faces.
Thanks ^_^