如何在Android上实现人脸解锁？

时间：2019-11-20 05:54:28

标签： java android

我想使用系统用于打开设备的面部解锁来打开我的应用程序

没有尝试过任何东西，因为我没有从哪里开始的线索。

1 个答案:

答案 0 :(得分：0)

在应用程序的build.gradle文件中添加以下依赖项。 

 compile 'com.google.android.gms:play-services-vision:11.0.4'

添加此元数据清单： 

   <meta-data
        android:name="com.google.android.gms.vision.DEPENDENCIES"
        android:value="face"/>


  <uses-feature
    android:name="android.hardware.camera"
    android:required="true"/>
 <uses-permission
    android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>


 The code for the activity_main.xml layout file is given below.


<android.support.constraint.ConstraintLayout xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    tools:context="com.journaldev.facedetectionapi.MainActivity">

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="300dp"
        android:layout_height="300dp"
        android:layout_marginTop="8dp"
        android:src="@drawable/sample_1"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/btnProcessNext"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:text="PROCESS NEXT"
        app:layout_constraintHorizontal_bias="0.501"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/imageView" />

    <ImageView
        android:id="@+id/imgTakePic"
        android:layout_width="250dp"
        android:layout_height="250dp"
        android:layout_marginTop="8dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/txtSampleDescription"
        app:srcCompat="@android:drawable/ic_menu_camera" />

    <Button
        android:id="@+id/btnTakePicture"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:text="TAKE PICTURE"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/imgTakePic" />

    <TextView
        android:id="@+id/txtSampleDescription"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginTop="8dp"
        android:gravity="center"
        app:layout_constraintBottom_toTopOf="@+id/txtTakePicture"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/btnProcessNext"
        app:layout_constraintVertical_bias="0.0" />

    <TextView
        android:id="@+id/txtTakePicture"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:gravity="center"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/btnTakePicture" />

</android.support.constraint.ConstraintLayout>

MainActivity.java文件的代码如下所示。。

package com.journaldev.facedetectionapi;

 import android.Manifest;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
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.TextView;
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.File;
import java.io.FileNotFoundException;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

ImageView imageView, imgTakePicture;
Button btnProcessNext, btnTakePicture;
TextView txtSampleDesc, txtTakenPicDesc;
private FaceDetector detector;
Bitmap editedBitmap;
int currentIndex = 0;
int[] imageArray;
private Uri imageUri;
private static final int REQUEST_WRITE_PERMISSION = 200;
private static final int CAMERA_REQUEST = 101;

private static final String SAVED_INSTANCE_URI = "uri";
private static final String SAVED_INSTANCE_BITMAP = "bitmap";

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

    imageArray = new int[]{R.drawable.sample_1, R.drawable.sample_2, R.drawable.sample_3};
    detector = new FaceDetector.Builder(getApplicationContext())
            .setTrackingEnabled(false)
            .setLandmarkType(FaceDetector.ALL_CLASSIFICATIONS)
            .setClassificationType(FaceDetector.ALL_CLASSIFICATIONS)
            .build();

    initViews();

}

private void initViews() {
    imageView = (ImageView) findViewById(R.id.imageView);
    imgTakePicture = (ImageView) findViewById(R.id.imgTakePic);
    btnProcessNext = (Button) findViewById(R.id.btnProcessNext);
    btnTakePicture = (Button) findViewById(R.id.btnTakePicture);
    txtSampleDesc = (TextView) findViewById(R.id.txtSampleDescription);
    txtTakenPicDesc = (TextView) findViewById(R.id.txtTakePicture);

    processImage(imageArray[currentIndex]);
    currentIndex++;

    btnProcessNext.setOnClickListener(this);
    btnTakePicture.setOnClickListener(this);
    imgTakePicture.setOnClickListener(this);
}

@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.btnProcessNext:
            imageView.setImageResource(imageArray[currentIndex]);
            processImage(imageArray[currentIndex]);
            if (currentIndex == imageArray.length - 1)
                currentIndex = 0;
            else
                currentIndex++;

            break;

        case R.id.btnTakePicture:
            ActivityCompat.requestPermissions(MainActivity.this, new
                    String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_WRITE_PERMISSION);
            break;

        case R.id.imgTakePic:
            ActivityCompat.requestPermissions(MainActivity.this, new
                    String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_WRITE_PERMISSION);
            break;
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    switch (requestCode) {
        case REQUEST_WRITE_PERMISSION:
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                startCamera();
            } else {
                Toast.makeText(getApplicationContext(), "Permission Denied!", Toast.LENGTH_SHORT).show();
            }
    }
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == CAMERA_REQUEST && resultCode == RESULT_OK) {
        launchMediaScanIntent();
        try {
            processCameraPicture();
        } catch (Exception e) {
            Toast.makeText(getApplicationContext(), "Failed to load Image", Toast.LENGTH_SHORT).show();
        }
    }
}

private void launchMediaScanIntent() {
    Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
    mediaScanIntent.setData(imageUri);
    this.sendBroadcast(mediaScanIntent);
}

private void startCamera() {
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    File photo = new File(Environment.getExternalStorageDirectory(), "photo.jpg");
    imageUri = Uri.fromFile(photo);
    intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
    startActivityForResult(intent, CAMERA_REQUEST);
}

@Override
protected void onSaveInstanceState(Bundle outState) {
    if (imageUri != null) {
        outState.putParcelable(SAVED_INSTANCE_BITMAP, editedBitmap);
        outState.putString(SAVED_INSTANCE_URI, imageUri.toString());
    }
    super.onSaveInstanceState(outState);
}


private void processImage(int image) {

    Bitmap bitmap = decodeBitmapImage(image);
    if (detector.isOperational() && bitmap != null) {
        editedBitmap = Bitmap.createBitmap(bitmap.getWidth(), bitmap
                .getHeight(), bitmap.getConfig());
        float scale = getResources().getDisplayMetrics().density;
        Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
        paint.setColor(Color.GREEN);
        paint.setTextSize((int) (16 * scale));
        paint.setShadowLayer(1f, 0f, 1f, Color.WHITE);
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeWidth(6f);
        Canvas canvas = new Canvas(editedBitmap);
        canvas.drawBitmap(bitmap, 0, 0, paint);
        Frame frame = new Frame.Builder().setBitmap(editedBitmap).build();
        SparseArray<Face> faces = detector.detect(frame);
        txtSampleDesc.setText(null);

        for (int index = 0; index < faces.size(); ++index) {
            Face face = faces.valueAt(index);
            canvas.drawRect(
                    face.getPosition().x,
                    face.getPosition().y,
                    face.getPosition().x + face.getWidth(),
                    face.getPosition().y + face.getHeight(), paint);


            canvas.drawText("Face " + (index + 1), face.getPosition().x + face.getWidth(), face.getPosition().y + face.getHeight(), paint);

            txtSampleDesc.setText(txtSampleDesc.getText() + "FACE " + (index + 1) + "\n");
            txtSampleDesc.setText(txtSampleDesc.getText() + "Smile probability:" + " " + face.getIsSmilingProbability() + "\n");
            txtSampleDesc.setText(txtSampleDesc.getText() + "Left Eye Is Open Probability: " + " " + face.getIsLeftEyeOpenProbability() + "\n");
            txtSampleDesc.setText(txtSampleDesc.getText() + "Right Eye Is Open Probability: " + " " + face.getIsRightEyeOpenProbability() + "\n\n");

            for (Landmark landmark : face.getLandmarks()) {
                int cx = (int) (landmark.getPosition().x);
                int cy = (int) (landmark.getPosition().y);
                canvas.drawCircle(cx, cy, 8, paint);
            }


        }

        if (faces.size() == 0) {
            txtSampleDesc.setText("Scan Failed: Found nothing to scan");
        } else {
            imageView.setImageBitmap(editedBitmap);
            txtSampleDesc.setText(txtSampleDesc.getText() + "No of Faces Detected: " + " " + String.valueOf(faces.size()));
        }
    } else {
        txtSampleDesc.setText("Could not set up the detector!");
    }
}

private Bitmap decodeBitmapImage(int image) {
    int targetW = 300;
    int targetH = 300;
    BitmapFactory.Options bmOptions = new BitmapFactory.Options();
    bmOptions.inJustDecodeBounds = true;

    BitmapFactory.decodeResource(getResources(), image,
            bmOptions);

    int photoW = bmOptions.outWidth;
    int photoH = bmOptions.outHeight;

    int scaleFactor = Math.min(photoW / targetW, photoH / targetH);
    bmOptions.inJustDecodeBounds = false;
    bmOptions.inSampleSize = scaleFactor;

    return BitmapFactory.decodeResource(getResources(), image,
            bmOptions);
}

private void processCameraPicture() throws Exception {
    Bitmap bitmap = decodeBitmapUri(this, imageUri);
    if (detector.isOperational() && bitmap != null) {
        editedBitmap = Bitmap.createBitmap(bitmap.getWidth(), bitmap
                .getHeight(), bitmap.getConfig());
        float scale = getResources().getDisplayMetrics().density;
        Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
        paint.setColor(Color.GREEN);
        paint.setTextSize((int) (16 * scale));
        paint.setShadowLayer(1f, 0f, 1f, Color.WHITE);
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeWidth(6f);
        Canvas canvas = new Canvas(editedBitmap);
        canvas.drawBitmap(bitmap, 0, 0, paint);
        Frame frame = new Frame.Builder().setBitmap(editedBitmap).build();
        SparseArray<Face> faces = detector.detect(frame);
        txtTakenPicDesc.setText(null);

        for (int index = 0; index < faces.size(); ++index) {
            Face face = faces.valueAt(index);
            canvas.drawRect(
                    face.getPosition().x,
                    face.getPosition().y,
                    face.getPosition().x + face.getWidth(),
                    face.getPosition().y + face.getHeight(), paint);


            canvas.drawText("Face " + (index + 1), face.getPosition().x + face.getWidth(), face.getPosition().y + face.getHeight(), paint);

            txtTakenPicDesc.setText("FACE " + (index + 1) + "\n");
            txtTakenPicDesc.setText(txtTakenPicDesc.getText() + "Smile probability:" + " " + face.getIsSmilingProbability() + "\n");
            txtTakenPicDesc.setText(txtTakenPicDesc.getText() + "Left Eye Is Open Probability: " + " " + face.getIsLeftEyeOpenProbability() + "\n");
            txtTakenPicDesc.setText(txtTakenPicDesc.getText() + "Right Eye Is Open Probability: " + " " + face.getIsRightEyeOpenProbability() + "\n\n");

            for (Landmark landmark : face.getLandmarks()) {
                int cx = (int) (landmark.getPosition().x);
                int cy = (int) (landmark.getPosition().y);
                canvas.drawCircle(cx, cy, 8, paint);
            }


        }

        if (faces.size() == 0) {
            txtTakenPicDesc.setText("Scan Failed: Found nothing to scan");
        } else {
            imgTakePicture.setImageBitmap(editedBitmap);
            txtTakenPicDesc.setText(txtTakenPicDesc.getText() + "No of Faces Detected: " + " " + String.valueOf(faces.size()));
        }
    } else {
        txtTakenPicDesc.setText("Could not set up the detector!");
    }
 }

 private Bitmap decodeBitmapUri(Context ctx, Uri uri) throws FileNotFoundException {
    int targetW = 300;
    int targetH = 300;
    BitmapFactory.Options bmOptions = new BitmapFactory.Options();
    bmOptions.inJustDecodeBounds = true;
    BitmapFactory.decodeStream(ctx.getContentResolver().openInputStream(uri), null, bmOptions);
    int photoW = bmOptions.outWidth;
    int photoH = bmOptions.outHeight;

    int scaleFactor = Math.min(photoW / targetW, photoH / targetH);
    bmOptions.inJustDecodeBounds = false;
    bmOptions.inSampleSize = scaleFactor;

    return BitmapFactory.decodeStream(ctx.getContentResolver()
            .openInputStream(uri), null, bmOptions);
}


@Override
protected void onDestroy() {
    super.onDestroy();
    detector.release();
 }
}

检测器使用以下代码段实例化： 

 FaceDetector detector = new FaceDetector.Builder( getContext() )
    .setTrackingEnabled(false)
    .setLandmarkType(FaceDetector.ALL_LANDMARKS)
    .setMode(FaceDetector.FAST_MODE)
    .build();

实际进行人脸检测的代码段是： 

  Frame frame = new Frame.Builder().setBitmap(editedBitmap).build();
        SparseArray faces = detector.detect(frame);

refer this link for more information

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