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Devmax。