face detection and crop

You must import Google Play Service
activity_layout

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

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

 android:layout_width="match_parent" 

 android:layout_height="match_parent" 

 android:orientation="vertical" 

 tools:context=".MainActivity">

    <package.FaceOverlayView 

 android:id="@+id/face_overlay" 

 android:layout_width="wrap_content" 

 android:layout_height="wrap_content" />

</LinearLayout>

MainActivity 

public class MainActivity extends AppCompatActivity {

    private FaceOverlayView mFaceOverlayView;

    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mFaceOverlayView = (FaceOverlayView) findViewById(R.id.face_overlay);
        mFaceOverlayView.setBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.img_2));
    }
}

FaceOverlayView 

public class FaceOverlayView extends View {

    private Bitmap mBitmap;
    private SparseArray<Face> mFaces;

    public FaceOverlayView(Context context) {
        this(context, null);
    }

    public FaceOverlayView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public FaceOverlayView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public void setBitmap(Bitmap bitmap) {
        mBitmap = bitmap;
        FaceDetector detector = new FaceDetector.Builder(getContext())
                .setTrackingEnabled(true)
                .setLandmarkType(FaceDetector.ALL_LANDMARKS)
                .setMode(FaceDetector.ACCURATE_MODE)
                .build();

        if (!detector.isOperational()) {
            //Handle contingency        } else {
            Frame frame = new Frame.Builder().setBitmap(bitmap).build();
            mFaces = detector.detect(frame);
            detector.release();
        }

        invalidate();
    }

    @Override    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        if ((mBitmap != null) && (mFaces != null)) {
            drawBitmap(canvas);
        }
    }

    private void drawBitmap(Canvas canvas) {
        double viewWidth = canvas.getWidth();
        double viewHeight = canvas.getHeight();
        double imageWidth = mBitmap.getWidth();
        double imageHeight = mBitmap.getHeight();
        int size = 200;
        float left = 0;
        float top = 0;
        float right = 0;
        float bottom = 0;
        for (int i = 0; i < mFaces.size(); i++) {
            Face face = mFaces.valueAt(i);
            left = (float) (face.getPosition().x);
            top = (float) (face.getPosition().y);
            right = (float) (face.getPosition().x + face.getWidth());
            bottom = (float) (face.getPosition().y + face.getHeight());
        }
        Rect src = new Rect((int) left, (int) top, (int) right, (int) bottom);
        Rect dst = new Rect(0, 0, size, size);
        canvas.drawBitmap(mBitmap, src, dst, null);
    }

}