Question

我正在尝试在我的Android应用中实施面部检测，因此我尝试了官方文档提供的示例应用：Google's Face Detection Sample App 我设法让应用程序运行并显示图像，但不会出现与地标相对应的小圆圈。在我上面提到的关于在安装应用程序时下载的库的教程中实际上有一个注释，这意味着可能无法立即获得面部检测。

 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，但等了一会儿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，但截至目前没有任何工作。日志中没有其他任何内容。

这是app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>

以下是使用isOperational（）方法的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

我遇到了这个问题，这些是我解决它的步骤

确保设备或仿真器上的存储空间高达500MB。
将Google Play服务更新至最新版本。由于发现了一些错误但在版本9.2中重新启用了人脸检测已暂停一段时间。
确保您的互联网连接正常。没有办法检查下载所需的本机库的进度，但应该在几分钟后完成。

希望这能节省几个小时。干杯！

Answer 2

这个问题很旧，但根据我的经验看来仍然很重要。使用此跟踪器时，我还遇到了两个重要的附加问题：

如果图像数据旋转不正确，面部检测器将不会抱怨，但只会检测不到任何东西。有一些脸部方向自由（向侧面倾斜），但旋转90°或相似肯定太多了
如果使用的是自定义ROM，则手机可能不是
已获得Play商店使用认证-您可以在此处获得证书：
https://www.google.com/android/uncertified/（但您需要计算
首先列出您的设备ID，它）

Android - 人脸检测库未加载

2 个答案: