Firebase 云文本识别

Firebase Cloud Text Recognition

当我尝试使用基于云的 API 进行文本识别时出现以下错误:

W/System.err: com.google.firebase.ml.common.FirebaseMLException: Internal error has occurred when executing Firebase ML tasks
        at com.google.android.gms.internal.firebase_ml.zzmy.zza(Unknown Source:35)
        at com.google.android.gms.internal.firebase_ml.zzmz.run(Unknown Source:2)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at com.google.android.gms.internal.firebase_ml.zze.dispatchMessage(Unknown Source:6)
        at android.os.Looper.loop(Looper.java:280)
        at android.os.HandlerThread.run(HandlerThread.java:65)
    Caused by: java.lang.NullPointerException: The input TextAnnotation can not be null
        at com.google.android.gms.common.internal.Preconditions.checkNotNull(Unknown Source:11)
        at com.google.android.gms.internal.firebase_ml.zzpj.zzb(Unknown Source:1)
        at com.google.android.gms.internal.firebase_ml.zzpf.zza(Unknown Source:38)
        at com.google.android.gms.internal.firebase_ml.zzoo.zza(Unknown Source:23)
        at com.google.android.gms.internal.firebase_ml.zznd.call(Unknown Source:4)
        at com.google.android.gms.internal.firebase_ml.zzmy.zza(Unknown Source:29)
        ... 6 more

我将检测器创建为

    private FirebaseVisionTextRecognizer cloudDetector = FirebaseVision.getInstance().getCloudTextRecognizer();

并使用以下方式调用检测器:

FirebaseVisionImage image = FirebaseVisionImage.fromBitmap(bm);
        Task<FirebaseVisionText> result =
                cloudDetector.processImage(image)
                        .addOnSuccessListener(new OnSuccessListener<FirebaseVisionText>() {
                            @Override
                            public void onSuccess(FirebaseVisionText firebaseVisionText) {
                                String text = firebaseVisionText.getText();
                                mFragment.setDetectedText(text);

                                // toggle isDetecting after 0.5 s. Do not want the textview to flickr to much
                                final Handler handler = new Handler();
                                handler.postDelayed(new Runnable() {
                                    @Override
                                    public void run() {
                                        isDetecting = false;
                                    }
                                }, delayTime);
                            }
                        })
                        .addOnFailureListener(
                                new OnFailureListener() {
                                    @Override
                                    public void onFailure(@NonNull Exception e) {
                                        // Task failed with an exception
                                        // ...
                                        Log.d("DETECTING", e.getMessage());
                                        e.printStackTrace();
                                    }
                                });

我在 Firebase 控制台中启用了云 API。此外,设备上的文本检测器运行良好。我也没有看到我的代码和示例代码之间有任何区别 here。有人经历过吗?

显然,与 deviceDetector 相比,Firebase 在 cloudDetector 中处理没有文本的图像的方式不同。

deviceDetctor 进入 onSuccess 但 cloudDetector 抛出 NullPtrException 并进入 onFailure。由于我在 onSuccess 中切换了一个布尔值,但在 onFailure 中没有切换,因此再也没有调用 cloudDetector。我现在也在 onFailure 中切换布尔值,并且有效。

话虽如此,对没有文字的图像采取不同的行为有点愚蠢。如果没有检测到文本,则没有任何问题,因此抛出异常似乎不合适。