Google Play services Face Detection, detect Smiling

With Face Detection of Google Play services, Mobile Vision API, you can detect various facial states; such as Smiling, Left Eye Open or Right Eye Open.

This example show how to detect Smiling face with getIsSmilingProbability() method of com.google.android.gms.vision.face.Face. You can also use getIsLeftEyeOpenProbability() and getIsRightEyeOpenProbability() methods to test if the face's left or right eye is open.


Modify from last post of "Google Play services Face Detection, get Landmarks (eyes, nose, etc.)". Call setClassificationType(FaceDetector.ALL_CLASSIFICATIONS) method when build FaceDetector with FaceDetector.Builder. Then call getIsSmilingProbability() method of the detected faces to check if it is similing.

package com.example.androidfacedetection;

import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PointF;
import android.graphics.RectF;
import android.graphics.drawable.BitmapDrawable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.SparseArray;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

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.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private static final int RQS_LOADIMAGE = 1;
    private Button btnLoad, btnDetFace;
    private ImageView imgView;
    private Bitmap myBitmap;

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

        btnLoad = (Button)findViewById(R.id.btnLoad);
        btnDetFace = (Button)findViewById(R.id.btnDetectFace);
        imgView = (ImageView)findViewById(R.id.imgview);

        btnLoad.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.setType("image/*");
                intent.setAction(Intent.ACTION_GET_CONTENT);
                intent.addCategory(Intent.CATEGORY_OPENABLE);
                startActivityForResult(intent, RQS_LOADIMAGE);
            }
        });

        btnDetFace.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {
                if(myBitmap == null){
                    Toast.makeText(MainActivity.this,
                            "myBitmap == null",
                            Toast.LENGTH_LONG).show();
                }else{
                    detectFace();

                }
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == RQS_LOADIMAGE
                && resultCode == RESULT_OK){

            if(myBitmap != null){
                myBitmap.recycle();
            }

            try {
                InputStream inputStream =
                        getContentResolver().openInputStream(data.getData());
                myBitmap = BitmapFactory.decodeStream(inputStream);
                inputStream.close();
                imgView.setImageBitmap(myBitmap);

            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
        super.onActivityResult(requestCode, resultCode, data);
    }

    /*
    reference:
    https://search-codelabs.appspot.com/codelabs/face-detection
     */
    private void detectFace(){

        //Create a Paint object for drawing with
        Paint myRectPaint = new Paint();
        myRectPaint.setStrokeWidth(5);
        myRectPaint.setColor(Color.GREEN);
        myRectPaint.setStyle(Paint.Style.STROKE);

        Paint landmarksPaint = new Paint();
        landmarksPaint.setStrokeWidth(10);
        landmarksPaint.setColor(Color.RED);
        landmarksPaint.setStyle(Paint.Style.STROKE);

        Paint smilingPaint = new Paint();
        smilingPaint.setStrokeWidth(4);
        smilingPaint.setColor(Color.YELLOW);
        smilingPaint.setStyle(Paint.Style.STROKE);

        boolean somebodySmiling = false;

        //Create a Canvas object for drawing on
        Bitmap tempBitmap = Bitmap.createBitmap(myBitmap.getWidth(), myBitmap.getHeight(), Bitmap.Config.RGB_565);
        Canvas tempCanvas = new Canvas(tempBitmap);
        tempCanvas.drawBitmap(myBitmap, 0, 0, null);

        //Detect the Faces

        //!!!
        //Cannot resolve method setTrackingEnabled(boolean)
        //FaceDetector faceDetector = new FaceDetector.Builder(getApplicationContext()).build();
        //faceDetector.setTrackingEnabled(false);

        FaceDetector faceDetector =
                new FaceDetector.Builder(getApplicationContext())
                .setTrackingEnabled(false)
                        .setLandmarkType(FaceDetector.ALL_LANDMARKS)
                        .setClassificationType(FaceDetector.ALL_CLASSIFICATIONS)
                        .build();

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

        //Draw Rectangles on the Faces
        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);

            //get Landmarks for the first face
            List<Landmark> landmarks = thisFace.getLandmarks();
            for(int l=0; l<landmarks.size(); l++){
                PointF pos = landmarks.get(l).getPosition();
                tempCanvas.drawPoint(pos.x, pos.y, landmarksPaint);
            }

            //check if this face is Smiling
            final float smilingAcceptProbability = 0.5f;
            float smilingProbability = thisFace.getIsSmilingProbability();
            if(smilingProbability > smilingAcceptProbability){
                tempCanvas.drawOval(new RectF(x1, y1, x2, y2), smilingPaint);
                somebodySmiling = true;
            }
        }

        imgView.setImageDrawable(new BitmapDrawable(getResources(), tempBitmap));

        if(somebodySmiling){
            Toast.makeText(MainActivity.this,
                    "Done - somebody is Smiling",
                    Toast.LENGTH_LONG).show();
        }else{
            Toast.makeText(MainActivity.this,
                    "Done - nobody is Smiling",
                    Toast.LENGTH_LONG).show();
        }
        
    }
}

Other files, AndroidManifest.xml and layout/activity_main.xml, refer to the post "Face Detection with Google Play services, Mobile Vision API".