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。