Firebase ML kit出现FirebaseMLException异常: 等待文本识别模型下载。请稍等。

Question

我正在使用Firebase ML Kit进行文本识别，但在模拟器和真实设备上都出现了这个异常。

W/System.err: com.google.firebase.ml.common.FirebaseMLException: Waiting for the text recognition model to be downloaded. Please wait.
    at com.google.android.gms.internal.firebase_ml.zzjz.zzc(Unknown Source)
    at com.google.android.gms.internal.firebase_ml.zzjz.zza(Unknown Source)
    at com.google.android.gms.internal.firebase_ml.zzic.call(Unknown Source)
    at com.google.android.gms.internal.firebase_ml.zzhx.zza(Unknown Source)
    at com.google.android.gms.internal.firebase_ml.zzhy.run(Unknown Source)
    at android.os.Handler.handleCallback(Handler.java:733)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at com.google.android.gms.internal.firebase_ml.zze.dispatchMessage(Unknown Source)
    at android.os.Looper.loop(Looper.java:136)
    at android.os.HandlerThread.run(HandlerThread.java:61)

这是我的代码

private fun MlProcessText(imageUri:Uri) {
    val bitmap = MediaStore.Images.Media.getBitmap(contentResolver, imageUri)
    val textVision = FirebaseVisionImage.fromBitmap(bitmap)
    val detector = FirebaseVision.getInstance().onDeviceTextRecognizer

    detector.processImage(textVision).addOnSuccessListener { it ->
        val blocks = it.textBlocks
        if (blocks.size == 0 ){

            tvVision.text = "NO TEXT"
        }else{
            blocks.forEach {
                tvVision.append(" ${it.text}")
            }
        }

    }.addOnFailureListener {
        it.printStackTrace() // this is the exception log
        tvVision.text = it.message
    }
}

我也尝试过:

1- 设置->应用->Google Play服务->存储->管理空间->清除所有数据

2- 检查可用空间（至少有1GB可用空间）

并添加元数据

 <meta-data
        android:name="com.google.firebase.ml.vision.DEPENDENCIES"
        android:value="ocr,text" />

但是还是出现同样的错误！

更新

在卡了几天之后，我试着使用了谷歌移动视觉

于是我将这个添加到我的依赖关系中

implementation 'com.google.android.gms:play-services-vision:17.0.2'

使用这篇文章进行OCR，在这段代码中。

    //Create the TextRecognizer
    final TextRecognizer textRecognizer = new TextRecognizer.Builder(getApplicationContext()).build();

    if (!textRecognizer.isOperational()) {
        Log.w(TAG, "Detector dependencies not loaded yet");
    } else {

        //Initialize camerasource to use high resolution and set Autofocus on.
        mCameraSource = new CameraSource.Builder(getApplicationContext(), textRecognizer)
                .setFacing(CameraSource.CAMERA_FACING_BACK)
                .setRequestedPreviewSize(1280, 1024)
                .setAutoFocusEnabled(true)
                .setRequestedFps(2.0f)
                .build();
     }

textRecognizer.isOperational() 总是返回 false，这意味着它也不起作用。 我认为这两个问题有共同点。

所以我还在为Android的文本识别器卡住了！

测试环境：Nox模拟器、Google Nexus 5X API 26模拟器、华为P10和三星Galaxy S7真实设备。

有没有什么想法可以解决这个问题？

- Radesh

Answer 1

TextRecognizer textRecognizer = new TextRecognizer.Builder(this).build();

    if(!textRecognizer.isOperational()) {
        // Note: The first time that an app using a Vision API is installed on a
        // device, GMS will download a native libraries 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 text,
        // barcodes, or faces.
        // isOperational() can be used to check if the required native libraries are currently
        // available.  The detectors will automatically become operational once the library
        // downloads complete on device.
        Log.w(LOG_TAG, "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,"Low Storage", Toast.LENGTH_LONG).show();
            Log.w(LOG_TAG, "Low Storage");
        }

- Sachin Kasaraddi

---

这是一个很好的检查存储空间的点，我会去做，并且 hasLowStorage 返回 false。 - Radesh

也可以像这个链接[link]（https://github.com/googlesamples/android-vision/issues/180）中建议的那样，在(!textRecognizer.isOperational)处等待一段时间。 - Sachin Kasaraddi

Answer 2

我注意到有时问题在于网络连接慢，只需要更多时间下载模型。 为了最小化糟糕的用户体验，我添加了这个热身方法并在应用启动时立即调用它，这样当实际识别发生时，模型已经被下载。

/**
 * We call that on startup with hope the needed model will be downloaded as soon as possible;
 * It is used to prevent: "Waiting for the text recognition model to be downloaded. Please wait."
 * exception when recognizing.
 */
public static void warmUp() {
    Bitmap image = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888);
    image.eraseColor(android.graphics.Color.GREEN);
    FirebaseVisionImage firebaseVisionImage = FirebaseVisionImage.fromBitmap(image);
    FirebaseVision.getInstance().getOnDeviceTextRecognizer()
            .processImage(firebaseVisionImage)
            .addOnSuccessListener(null)
            .addOnFailureListener(null);
}

- Trayan Momkov

Answer 3

尝试从 Google Play 服务中卸载更新。

- user8141496

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请进一步详细说明：为什么，如何，何处。 - m02ph3u5