Android - 人脸检测库不加载

Question

我想在我的Android应用程序中实现人脸检测，所以我尝试了这里的官方文档提供的示例应用程序：Google's Face Detection Sample App 我确实设法让应用程序运行并显示图像，但与地标相对应的小圆圈不会出现。实际上，我在上面提到的教程中提到了有关安装应用程序时下载的库的说明，这意味着可能无法立即使用人脸检测。

if (!safeDetector.isOperational()) { 
     // Note: The first time that an app using face API is installed on a device, GMS will 
     // download a native library to the device in order to do detection. Usually this 
     // completes before the app is run for the first time. But if that download has not yet 
     // completed, then the above call will not detect any faces. 
     // 
     // isOperational() can be used to check if the required native library is currently 
     // available. The detector will automatically become operational once the library 
     // download completes on device. 
     Log.w(TAG, "Face detector dependencies are not yet available."); 

我的日志包含上面的行，但等待一段时间后，我仍然没有得到任何东西。我尝试关闭并重新打开应用程序，并重新安装它，但目前没有任何工作。日志中没有其他内容。

这里是应用程序的的build.gradle：

apply plugin: 'com.android.application' 

android { 
    compileSdkVersion 23 
    buildToolsVersion "22.0.1" 

defaultConfig { 
    applicationId "com.google.android.gms.samples.vision.face.photo" 
    minSdkVersion 9 
    targetSdkVersion 23 
    versionCode 1 
    versionName "1.0" 
} 
buildTypes { 
    release { 
     minifyEnabled false 
     proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' 
    } 
    } 
} 

dependencies { 
    compile fileTree(dir: 'libs', include: ['*.jar']) 
    compile 'com.android.support:appcompat-v7:23.0.0' 
    compile 'com.google.android.gms:play-services:8.4.0' 
} 

这里是清单：

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
    package="com.google.android.gms.samples.vision.face.photo" 
    android:installLocation="auto" 
    android:versionCode="1" 
    android:versionName="1" > 

<uses-sdk 
    android:minSdkVersion="9" 
    android:targetSdkVersion="21" /> 

<application 
    android:hardwareAccelerated="true" 
    android:label="FacePhotoDemo" 
    android:allowBackup="true" 
    android:icon="@drawable/icon"> 

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

    <activity 
     android:name=".PhotoViewerActivity" 
     android:icon="@drawable/icon" 
     android:label="@string/title_activity_photo_viewer" 
     android:theme="@android:style/Theme.Black.NoTitleBar" 
     android:screenOrientation="fullSensor"> 
     <intent-filter> 
      <action android:name="android.intent.action.MAIN" /> 
      <category android:name="android.intent.category.LAUNCHER" /> 
     </intent-filter> 
    </activity> 
</application> 

这里是其是当使用isOperational（）方法PhotoViewerActivity：

/* 
* Copyright (C) The Android Open Source Project 
* 
* Licensed under the Apache License, Version 2.0 (the "License"); 
* you may not use this file except in compliance with the License. 
* You may obtain a copy of the License at 
* 
*  http://www.apache.org/licenses/LICENSE-2.0 
* 
* Unless required by applicable law or agreed to in writing, software 
* distributed under the License is distributed on an "AS IS" BASIS, 
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
* See the License for the specific language governing permissions and 
* limitations under the License. 
*/ 
package com.google.android.gms.samples.vision.face.photo; 

import android.app.Activity; 
import android.content.Intent; 
import android.content.IntentFilter; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.os.Bundle; 
import android.util.Log; 
import android.util.SparseArray; 
import android.widget.Toast; 

import com.google.android.gms.samples.vision.face.patch.SafeFaceDetector; 
import com.google.android.gms.vision.Detector; 
import com.google.android.gms.vision.Frame; 
import com.google.android.gms.vision.face.Face; 
import com.google.android.gms.vision.face.FaceDetector; 

import java.io.InputStream; 

/** 
* Demonstrates basic usage of the GMS vision face detector by running face landmark detection on a 
* photo and displaying the photo with associated landmarks in the UI. 
*/ 
public class PhotoViewerActivity extends Activity { 
    private static final String TAG = "PhotoViewerActivity"; 

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

     InputStream stream = getResources().openRawResource(R.raw.face); 
     Bitmap bitmap = BitmapFactory.decodeStream(stream); 

     // A new face detector is created for detecting the face and its landmarks. 
     // 
     // Setting "tracking enabled" to false is recommended for detection with unrelated 
     // individual images (as opposed to video or a series of consecutively captured still 
     // images). For detection on unrelated individual images, this will give a more accurate 
     // result. For detection on consecutive images (e.g., live video), tracking gives a more 
     // accurate (and faster) result. 
     // 
     // By default, landmark detection is not enabled since it increases detection time. We 
     // enable it here in order to visualize detected landmarks. 
     FaceDetector detector = new FaceDetector.Builder(getApplicationContext()) 
       .setTrackingEnabled(false) 
       .setLandmarkType(FaceDetector.ALL_LANDMARKS) 
       .build(); 

     // This is a temporary workaround for a bug in the face detector with respect to operating 
     // on very small images. This will be fixed in a future release. But in the near term, use 
     // of the SafeFaceDetector class will patch the issue. 
     Detector<Face> safeDetector = new SafeFaceDetector(detector); 

     // Create a frame from the bitmap and run face detection on the frame. 
     Frame frame = new Frame.Builder().setBitmap(bitmap).build(); 
     SparseArray<Face> faces = safeDetector.detect(frame); 

     if (!safeDetector.isOperational()) { 
      // Note: The first time that an app using face API is installed on a device, GMS will 
      // download a native library to the device in order to do detection. Usually this 
      // completes before the app is run for the first time. But if that download has not yet 
      // completed, then the above call will not detect any faces. 
      // 
      // isOperational() can be used to check if the required native library is currently 
      // available. The detector will automatically become operational once the library 
      // download completes on device. 
      Log.w(TAG, "Face detector dependencies are not yet available."); 

      // Check for low storage. If there is low storage, the native library will not be 
      // downloaded, so detection will not become operational. 
      IntentFilter lowstorageFilter = new IntentFilter(Intent.ACTION_DEVICE_STORAGE_LOW); 
      boolean hasLowStorage = registerReceiver(null, lowstorageFilter) != null; 

      if (hasLowStorage) { 
       Toast.makeText(this, R.string.low_storage_error, Toast.LENGTH_LONG).show(); 
       Log.w(TAG, getString(R.string.low_storage_error)); 
      } 
     } 

     FaceView overlay = (FaceView) findViewById(R.id.faceView); 
     overlay.setContent(bitmap, faces); 

     // Although detector may be used multiple times for different images, it should be released 
     // when it is no longer needed in order to free native resources. 
     safeDetector.release(); 
    } 
} 

Answer 1

我有这个问题，这些是我采取的解决它的步骤

1. 确保设备或模拟器上有多达500MB的存储空间。
2. 将Google Play服务更新到最新版本。由于发现了一些在9.2版本中重新启用的错误，脸部检测已被禁用了一段时间。
3. 确保您的互联网连接正常工作。没有办法检查所需的本地库的下载进度，但应在几分钟后完成。

希望这可以节省几个小时。 干杯！