浏览图像和面部检测

Question

I am having some issues with detecting faces of a browsed image. I know the issue is that I do not know how to apply the face detection code I am testing out on an imported image. The example code I am testing was written for an image stored locally. I believe I am close but can you help me out?

First, I created a gallery method

    protected void gallery() {
    Intent intent = new Intent();
    intent.setType("image/*");
    intent.setAction("android.intent.action.GET_CONTENT");
    startActivityForResult(Intent.createChooser(intent, "Choose An Image"), 1);         
}

I am still learning about intents and such, but as far as I understand I needed to use the intent to use Android's gallery, and because I setAction to get content, I am also using the intent to pass information to it. With that said, I tried to then pass the information in the intent to a uri. So this is what I did next.

protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
    super.onActivityResult(requestCode, resultCode, intent);
    if(requestCode == 1 && resultCode == RESULT_OK)
    {
        Uri uri = intent.getData();
        try {
            InputStream is = getContentResolver().openInputStream(uri);
            Bitmap bitmap = BitmapFactory.decodeStream(is);
            ImageView image = (ImageView)findViewById(R.id.img_view);
            image.setImageBitmap(bitmap);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

So here is the confusing part for me. I guess InputStream has the image information? Well I tried to apply the face detection code inside this same try-catch. I figured that after image.setImageBitmap(bitmap) is completed, that is the time to apply face detection. Here is the face detection code.

protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
    super.onActivityResult(requestCode, resultCode, intent);
    if(requestCode == 1 && resultCode == RESULT_OK)
    {
        Uri uri = intent.getData();
        try {
            InputStream is = getContentResolver().openInputStream(uri);
            Bitmap bitmap = BitmapFactory.decodeStream(is);
            ImageView image = (ImageView)findViewById(R.id.image_view);
            image.setImageBitmap(bitmap);

            BitmapFactory.Options options = new BitmapFactory.Options();
            options.inPreferredConfig=Bitmap.Config.RGB_565;
            bitmap = BitmapFactory.decodeResource(getResources(), R.id.img_view, options);

            imageWidth = bitmap.getWidth();
            imageHeight = bitmap.getHeight();
            detectedFaces = new FaceDetector.Face[NUM_FACES];
            faceDetector= new FaceDetector(imageWidth, imageHeight, NUM_FACES);
            NUM_FACE_DETECTED = faceDetector.findFaces(bitmap, detectedFaces);
            mIL.invalidate();
        } catch (Exception e) {
            e.printStackTrace();
        }   
    }
}

I do not know how to change "mFaceBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.smilingfaces, options);" which is for local images, to the image that I think is stored inside the InputStream (or is it? Where is the selected image?) I came up with the idea to instead do the imageView layout, since the image is in the layout. I do not understand how that all transfers and works together. Anyway, that code snippet is suppose to detect faces. And then onDraw() draws squares around the detected faces. I am not sure where to put it, but I placed it outside of the onActivityResult()

protected void onDraw(Canvas canvas) {

    Paint myPaint = new Paint();
    myPaint.setColor(Color.RED);
    myPaint.setStyle(Paint.Style.STROKE);
    myPaint.setStrokeWidth(3);
    myPaint.setDither(true);

    for (int count = 0; count < NUM_FACE_DETECTED; count++) {
        Face face = detectedFaces[count];
        PointF midPoint = new PointF();
        face.getMidPoint(midPoint);

        eyeDistance = face.eyesDistance();
        canvas.drawRect(midPoint.x-eyeDistance, midPoint.y-eyeDistance, midPoint.x+eyeDistance, midPoint.y+eyeDistance, myPaint);   
    }
}

Any advice? I am very close to getting this to work!

Answer 1

I understood what you actually want. I will write you the complete code and just go along.

In this code i am taking an imageview in layout, and two classes , one activity class and other is imageview class.

I will create two buttons, where one button is used to select image from gallery and display it ( for face detection) and second button for detecting faces on the selected image.

firstly mainlayout.xml

<?xml version="1.0" encoding="utf-8"?>

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >

<com.simpleapps.facedetection.MyView
android:id="@+id/faceview"
android:layout_width="fill_parent" 
android:layout_height="fill_parent" 
/>

<LinearLayout 
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_gravity="top">

<ImageView
    android:id="@+id/gallery"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginRight="10dp"
    android:layout_weight="1"
   android:background="@drawable/gallery" />

<ImageView
    android:id="@+id/detectf"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginRight="10dp"
    android:layout_weight="1"
   android:background="@drawable/detect" />


</LinearLayout>
</FrameLayout>

now the activity class

MainActivity.java

 public class MainActivity extends Activity {

public MyView faceview;

public static Bitmap defaultBitmap;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
     requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);

        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

    setContentView(R.layout.activity_main);

     DisplayMetrics displaymetrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
        screenHeight = displaymetrics.heightPixels;  
        screenWidth = displaymetrics.widthPixels; 

          faceview = (MyView)findViewById(R.id.faceview);

             myGallery = (LinearLayout)findViewById(R.id.mygallery);





          gallery=(ImageView)findViewById(R.id.gallery);
          detectf=(ImageView)findViewById(R.id.detectf);



          BitmapFactory.Options bitmapFatoryOptions=new BitmapFactory.Options();
            bitmapFatoryOptions.inPreferredConfig=Bitmap.Config.RGB_565;

          defaultBitmap=BitmapFactory.decodeResource(getResources(), R.drawable.face,bitmapFatoryOptions);

            faceview.setImage(defaultBitmap);

          gallery.setOnClickListener(new OnClickListener() {

                public void onClick(View v) {
                    // TODO Auto-generated method stub

                    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
                    intent.setType("image/*");
                    startActivityForResult(intent, 0 );

                }
            });

          detectf.setOnClickListener(new OnClickListener() {

                public void onClick(View v) {
                    // TODO Auto-generated method stub


                    faceview.facedetect();

                }
            });

  }

 @Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {

    super.onActivityResult(requestCode, resultCode, data);

    if (resultCode == Activity.RESULT_OK) {

        if(requestCode==0){

        imageURI = data.getData(); 

        try {

             BitmapFactory.Options bitmapFatoryOptions=new BitmapFactory.Options();
            bitmapFatoryOptions.inPreferredConfig=Bitmap.Config.RGB_565;

            Bitmap b =  
                       BitmapFactory.decodeStream(getContentResolver().openInputStream(imageURI), null,  
                               bitmapFatoryOptions);


            faceview.myBitmap=b;


        } catch (FileNotFoundException e) {
//               TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
//               TODO Auto-generated catch block  
            e.printStackTrace();
        }


        faceview.invalidate(); 

        }

        faceview.invalidate(); 
    } else {
        System.exit(0);
        Log.e("result", "BAD");
    }
 }
 }

now the view class.

MyView.java

public class MyView extends View {

private FaceDetector.Face[] detectedFaces;
private int NUMBER_OF_FACES=10;
private FaceDetector faceDetector;
private int NUMBER_OF_FACE_DETECTED;
private float eyeDistance;

public Paint myPaint;

public Bitmap resultBmp;

public Bitmap myBitmap,HairBitmap;

public PointF midPoint1;

public MyView(Context context, AttributeSet attrs) {
    super(context,attrs);
    // TODO Auto-generated constructor stub
    BitmapFactory.Options bitmapFatoryOptions=new BitmapFactory.Options();
    bitmapFatoryOptions.inPreferredConfig=Bitmap.Config.RGB_565;

}

public void setImage(Bitmap bitmap) {
    myBitmap = bitmap;

invalidate();
}


public void facedetect(){

     myPaint = new Paint();
        myPaint.setColor(Color.GREEN);
        myPaint.setStyle(Paint.Style.STROKE); 
        myPaint.setStrokeWidth(3);

    detectedFaces=new FaceDetector.Face[NUMBER_OF_FACES];
    faceDetector=new FaceDetector(resultBmp.getWidth(),resultBmp.getHeight(),NUMBER_OF_FACES);
    NUMBER_OF_FACE_DETECTED=faceDetector.findFaces(resultBmp, detectedFaces);

    System.out.println("faces detected are"+NUMBER_OF_FACE_DETECTED);

    Canvas facec=new Canvas();

    for(int count=0;count<NUMBER_OF_FACE_DETECTED;count++)
   {

    if(count==0){

         face1=detectedFaces[count];
        midPoint1=new PointF();
        face1.getMidPoint(midPoint1);

        eyeDistance=face1.eyesDistance();


    }

   }

    invalidate();

    if(NUMBER_OF_FACE_DETECTED==0){

    Toast.makeText(getContext(), "no faces detected", Toast.LENGTH_LONG).show(); 

    }else if(NUMBER_OF_FACE_DETECTED!=0){

        Toast.makeText(getContext(), "faces detected "+NUMBER_OF_FACE_DETECTED, Toast.LENGTH_LONG).show(); 

    }
}

protected void onDraw(Canvas canvas)
{

    if(myBitmap!=null)
    {



     w = myBitmap.getWidth();
     h = myBitmap.getHeight();
     resultBmp = null;

     int widthofBitMap  = MainActivity.screenWidth ;
     int heightofBitMap = widthofBitMap*h/w;

    resultBmp = Bitmap.createScaledBitmap(myBitmap, widthofBitMap, heightofBitMap, true);  
    canvas.drawBitmap(resultBmp, (MainActivity.screenWidth-widthofBitMap)/2,(MainActivity.screenHeight-heightofBitMap)/2, null);


    }

} 

@Override

  public boolean onTouchEvent(MotionEvent event) {
   // TODO Auto-generated method stub

   int action = event.getAction();



   switch(action){
   case MotionEvent.ACTION_MOVE:
    x = event.getX();
    y = event.getY();





    break;
   case MotionEvent.ACTION_DOWN:
    x = event.getX();
    y = event.getY();





    break;
   case MotionEvent.ACTION_UP:
   default:


}
   invalidate();
   return true;
  }


  }

I took some time to write this code. I hope it helps. If you get some error just ask.