Android开发人脸识别统计人脸数

本文实例为大家分享了Android开发人脸识别统计的具体代码，供大家参考，具体内容如下

最近项目需求是统计当前摄像头中的人脸个数，安卓有提供现成的Api，最终实现效果如上图。

分析思路和步奏：

主要使用到的类：SurfaceView、CameraManager、CameraDevice.StateCallback、CameraCaptureSession.StateCallback。

1.通过SurfaceView展示预览区。
2.在SurfaceView创建成功后通过CameraManager获取当前设备可用的摄像头。
3.检测摄像头权限。
4.通过CameraManager打开摄像头。
5.在打开成功的回调中通过CameraDevice创建会话。
6.在会话创建成功的回调方法中创建预览请求。
7.在预览请求的回调方法onCaptureCompleted()方法中获取预览界面中返回的人脸数。

以下是实现步骤：

1.xml

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

 <SurfaceView
  android:id="@+id/sv"
  android:layout_width="match_parent"
  android:layout_height="0dp"
  android:layout_weight="1" />
</LinearLayout>

java

cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
  surfaceHolder = sv.getHolder();
  surface = surfaceHolder.getSurface();

//获取可用的相机列表
     String[] cameraIdList = cameraManager.getCameraIdList();

if (checkSelfPermission(Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
      // TODO: Consider calling
      // Activity#requestPermissions
      // here to request the missing permissions, and then overriding
      // public void onRequestPermissionsResult(int requestCode, String[] permissions,
      //           int[] grantResults)
      // to handle the case where the user grants the permission. See the documentation
      // for Activity#requestPermissions for more details.
      return;
     }

//获取开启相机的相关参数
     CameraCharacteristics characteristics = cameraManager.getCameraCharacteristics(cameraIdList[1]);
     //可用于判断是否支持人脸检测，以及支持到哪种程度
     faceDetectModes = characteristics.get(CameraCharacteristics.STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES);//支持的人脸检测模式
     cameraManager.openCamera(cameraIdList[1], mStateCallback, null);

camera.createCaptureSession(Arrays.asList(surface), new CameraCaptureSession.StateCallback() {
     @Override
     public void onConfigured(@NonNull CameraCaptureSession session) {
      
     }

     @Override
     public void onConfigureFailed(@NonNull CameraCaptureSession session) {

     }
    }, new Handler());

CaptureRequest.Builder captureRequest = camera.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
       captureRequest.addTarget(surface);
       captureRequest.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
       captureRequest.set(CaptureRequest.STATISTICS_FACE_DETECT_MODE, getFaceDetectMode());
       session.setRepeatingRequest(captureRequest.build(),captureCallback,new Handler());

 /**
  * 预览回调
  */
 private CameraCaptureSession.CaptureCallback captureCallback = new CameraCaptureSession.CaptureCallback() {
  @Override
  public void onCaptureStarted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, long timestamp, long frameNumber) {
   super.onCaptureStarted(session, request, timestamp, frameNumber);
  }

  @Override
  public void onCaptureProgressed(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull CaptureResult partialResult) {
   super.onCaptureProgressed(session, request, partialResult);
  }

  @Override
  public void onCaptureCompleted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {
   super.onCaptureCompleted(session, request, result);
   Face faces[] = result.get(CaptureResult.STATISTICS_FACES);
   if (faces.length != face) {
    Log.e("lee", faces.length + "张脸");
   }
  }

  @Override
  public void onCaptureFailed(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull CaptureFailure failure) {
   super.onCaptureFailed(session, request, failure);
  }

  @Override
  public void onCaptureSequenceCompleted(@NonNull CameraCaptureSession session, int sequenceId, long frameNumber) {
   super.onCaptureSequenceCompleted(session, sequenceId, frameNumber);
  }

  @Override
  public void onCaptureSequenceAborted(@NonNull CameraCaptureSession session, int sequenceId) {
   super.onCaptureSequenceAborted(session, sequenceId);
  }

  @Override
  public void onCaptureBufferLost(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull Surface target, long frameNumber) {
   super.onCaptureBufferLost(session, request, target, frameNumber);
  }
 };

以下就是所有代码：

MainActivity.java

package com.zg.lcddemo;

import android.Manifest;
import android.content.ContentValues;
import android.content.Context;
import android.content.pm.PackageManager;
import android.content.res.Configuration;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.ImageFormat;
import android.graphics.Rect;
import android.graphics.SurfaceTexture;
import android.hardware.Camera;
import android.hardware.camera2.CameraAccessException;
import android.hardware.camera2.CameraCaptureSession;
import android.hardware.camera2.CameraCharacteristics;
import android.hardware.camera2.CameraDevice;
import android.hardware.camera2.CameraManager;
import android.hardware.camera2.CameraMetadata;
import android.hardware.camera2.CaptureFailure;
import android.hardware.camera2.CaptureRequest;
import android.hardware.camera2.CaptureResult;
import android.hardware.camera2.TotalCaptureResult;
import android.hardware.camera2.params.Face;
import android.hardware.camera2.params.SessionConfiguration;
import android.hardware.camera2.params.StreamConfigurationMap;
import android.media.FaceDetector;
import android.media.ImageReader;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Message;
import android.provider.MediaStore;
import android.util.Log;
import android.util.Size;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.Semaphore;

public class MainActivity extends AppCompatActivity {
 private SurfaceView sv;
 private SurfaceHolder surfaceHolder;
 private CameraManager cameraManager;
 private Surface surface;
 int[] faceDetectModes;
 int face;
 List<Bitmap> bitmaps = new ArrayList<>();

 /**
  * 获取支持的最高人脸检测级别
  *
  * @return
  */
 private int getFaceDetectMode() {
  if (faceDetectModes == null) {
   return CaptureRequest.STATISTICS_FACE_DETECT_MODE_FULL;
  } else {
   return faceDetectModes[faceDetectModes.length - 1];
  }
 }

 @RequiresApi(api = Build.VERSION_CODES.M)
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  sv = findViewById(R.id.sv);
  cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
  surfaceHolder = sv.getHolder();
  surface = surfaceHolder.getSurface();
  surfaceHolder.addCallback(new SurfaceHolder.Callback() {
   @RequiresApi(api = Build.VERSION_CODES.M)
   @Override
   public void surfaceCreated(SurfaceHolder holder) {
    try {
     //获取可用的相机列表
     String[] cameraIdList = cameraManager.getCameraIdList();
     if (checkSelfPermission(Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
      // TODO: Consider calling
      // Activity#requestPermissions
      // here to request the missing permissions, and then overriding
      // public void onRequestPermissionsResult(int requestCode, String[] permissions,
      //           int[] grantResults)
      // to handle the case where the user grants the permission. See the documentation
      // for Activity#requestPermissions for more details.
      return;
     }
     //获取开启相机的相关参数
     CameraCharacteristics characteristics = cameraManager.getCameraCharacteristics(cameraIdList[1]);
     //可用于判断是否支持人脸检测，以及支持到哪种程度
     faceDetectModes = characteristics.get(CameraCharacteristics.STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES);//支持的人脸检测模式
     cameraManager.openCamera(cameraIdList[1], mStateCallback, null);
    } catch (CameraAccessException e) {
     e.printStackTrace();
    }
   }

   @Override
   public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

   }

   @Override
   public void surfaceDestroyed(SurfaceHolder holder) {

   }
  });

 }

 /**
  * 相机状态回调
  */
 private CameraDevice.StateCallback mStateCallback = new CameraDevice.StateCallback() {
  @Override
  public void onOpened(@NonNull final CameraDevice camera) {
   //打开成功，可以获取CameraDevice对象
   try {
    camera.createCaptureSession(Arrays.asList(surface), new CameraCaptureSession.StateCallback() {
     @Override
     public void onConfigured(@NonNull CameraCaptureSession session) {
      try {
       CaptureRequest.Builder captureRequest = camera.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
       captureRequest.addTarget(surface);
       captureRequest.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
       captureRequest.set(CaptureRequest.STATISTICS_FACE_DETECT_MODE, getFaceDetectMode());
       session.setRepeatingRequest(captureRequest.build(),captureCallback,new Handler());
      } catch (CameraAccessException e) {
       e.printStackTrace();
      }
     }

     @Override
     public void onConfigureFailed(@NonNull CameraCaptureSession session) {

     }
    }, new Handler());
   } catch (CameraAccessException e) {
    e.printStackTrace();
   }

  }

  @Override
  public void onDisconnected(@NonNull CameraDevice camera) {
   //断开连接
   Toast.makeText(MainActivity.this, "onDisconnected", Toast.LENGTH_SHORT).show();
  }

  @Override
  public void onError(@NonNull CameraDevice camera, final int error) {
   //发生异常
   Toast.makeText(MainActivity.this, "onError", Toast.LENGTH_SHORT).show();
  }
 };


 /**
  * 预览回调
  */
 private CameraCaptureSession.CaptureCallback captureCallback = new CameraCaptureSession.CaptureCallback() {
  @Override
  public void onCaptureStarted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, long timestamp, long frameNumber) {
   super.onCaptureStarted(session, request, timestamp, frameNumber);
  }

  @Override
  public void onCaptureProgressed(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull CaptureResult partialResult) {
   super.onCaptureProgressed(session, request, partialResult);
  }

  @Override
  public void onCaptureCompleted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {
   super.onCaptureCompleted(session, request, result);
   Face faces[] = result.get(CaptureResult.STATISTICS_FACES);
   if (faces.length != face) {
    Log.e("lee", faces.length + "张脸");
    face = faces.length;  
   }
  }

  @Override
  public void onCaptureFailed(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull CaptureFailure failure) {
   super.onCaptureFailed(session, request, failure);
  }

  @Override
  public void onCaptureSequenceCompleted(@NonNull CameraCaptureSession session, int sequenceId, long frameNumber) {
   super.onCaptureSequenceCompleted(session, sequenceId, frameNumber);
  }

  @Override
  public void onCaptureSequenceAborted(@NonNull CameraCaptureSession session, int sequenceId) {
   super.onCaptureSequenceAborted(session, sequenceId);
  }

  @Override
  public void onCaptureBufferLost(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull Surface target, long frameNumber) {
   super.onCaptureBufferLost(session, request, target, frameNumber);
  }
 };
}

xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:orientation="vertical">

 <SurfaceView
  android:id="@+id/sv"
  android:layout_width="match_parent"
  android:layout_height="0dp"
  android:layout_weight="1" />
</LinearLayout>

以上就能实现统计当前摄像头下有多少个人脸。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。