安卓 OCR : Cannot resolve error for getBoundingBox

Question

我是一名学生，也是 android 开发的初学者，需要为我的学校项目的联系人管理应用程序执行 android OCR 功能。这是为了将名片中的图像转换为文本。

我在许多论坛上搜索了有关这方面的信息，并找到了几个很好的例子。

目前我在网上找到了一个开源代码，不需要设置ndk和环境变量等来设置。然而，当我将它实现到 eclipse(juno) 中时，出现了一个小错误，我不确定如何解决。

我在谷歌上搜索了很长时间，没有任何结果。因此，决定在这里问问。以下是有错误的代码。

    final class OcrRecognizeAsyncTask extends AsyncTask<Void, Void, Boolean> {

  //  private static final boolean PERFORM_FISHER_THRESHOLDING = false; 
  //  private static final boolean PERFORM_OTSU_THRESHOLDING = false; 
  //  private static final boolean PERFORM_SOBEL_THRESHOLDING = false; 

  private CaptureActivity activity;
  private TessBaseAPI baseApi;
  private byte[] data;
  private int width;
  private int height;
  private OcrResult ocrResult;
  private long timeRequired;

  OcrRecognizeAsyncTask(CaptureActivity activity, TessBaseAPI baseApi, byte[] data, int width, int height) {
    this.activity = activity;
    this.baseApi = baseApi;
    this.data = data;
    this.width = width;
    this.height = height;
  }

  @Override
  protected Boolean doInBackground(Void... arg0) {
    long start = System.currentTimeMillis();
    Bitmap bitmap = activity.getCameraManager().buildLuminanceSource(data, width, height).renderCroppedGreyscaleBitmap();
    String textResult;

    //      if (PERFORM_FISHER_THRESHOLDING) {
    //        Pix thresholdedImage = Thresholder.fisherAdaptiveThreshold(ReadFile.readBitmap(bitmap), 48, 48, 0.1F, 2.5F);
    //        Log.e("OcrRecognizeAsyncTask", "thresholding completed. converting to bmp. size:" + bitmap.getWidth() + "x" + bitmap.getHeight());
    //        bitmap = WriteFile.writeBitmap(thresholdedImage);
    //      }
    //      if (PERFORM_OTSU_THRESHOLDING) {
    //        Pix thresholdedImage = Binarize.otsuAdaptiveThreshold(ReadFile.readBitmap(bitmap), 48, 48, 9, 9, 0.1F);
    //        Log.e("OcrRecognizeAsyncTask", "thresholding completed. converting to bmp. size:" + bitmap.getWidth() + "x" + bitmap.getHeight());
    //        bitmap = WriteFile.writeBitmap(thresholdedImage);
    //      }
    //      if (PERFORM_SOBEL_THRESHOLDING) {
    //        Pix thresholdedImage = Thresholder.sobelEdgeThreshold(ReadFile.readBitmap(bitmap), 64);
    //        Log.e("OcrRecognizeAsyncTask", "thresholding completed. converting to bmp. size:" + bitmap.getWidth() + "x" + bitmap.getHeight());
    //        bitmap = WriteFile.writeBitmap(thresholdedImage);
    //      }

    try {     
      baseApi.setImage(ReadFile.readBitmap(bitmap));
      textResult = baseApi.getUTF8Text();
      timeRequired = System.currentTimeMillis() - start;

      // Check for failure to recognize text
      if (textResult == null || textResult.equals("")) {
        return false;
      }
      ocrResult = new OcrResult();
      ocrResult.setWordConfidences(baseApi.wordConfidences());
      ocrResult.setMeanConfidence( baseApi.meanConfidence());
      ocrResult.setRegionBoundingBoxes(baseApi.getRegions().getBoxRects());
      ocrResult.setTextlineBoundingBoxes(baseApi.getTextlines().getBoxRects());
      ocrResult.setWordBoundingBoxes(baseApi.getWords().getBoxRects());
      ocrResult.setStripBoundingBoxes(baseApi.getStrips().getBoxRects());

      // Iterate through the results.
      final ResultIterator iterator = baseApi.getResultIterator();
      int[] lastBoundingBox;
      ArrayList<Rect> charBoxes = new ArrayList<Rect>();
      iterator.begin();
      do {
          lastBoundingBox =iterator.getBoundingBox(PageIteratorLevel.RIL_SYMBOL);
          Rect lastRectBox = new Rect(lastBoundingBox[0], lastBoundingBox[1],
                  lastBoundingBox[2], lastBoundingBox[3]);
          charBoxes.add(lastRectBox);
      } while (iterator.next(PageIteratorLevel.RIL_SYMBOL));
      iterator.delete();
      ocrResult.setCharacterBoundingBoxes(charBoxes);

    } catch (RuntimeException e) {
      Log.e("OcrRecognizeAsyncTask", "Caught RuntimeException in request to Tesseract. Setting state to CONTINUOUS_STOPPED.");
      e.printStackTrace();
      try {
        baseApi.clear();
        activity.stopHandler();
      } catch (NullPointerException e1) {
        // Continue
      }
      return false;
    }
    timeRequired = System.currentTimeMillis() - start;
    ocrResult.setBitmap(bitmap);
    ocrResult.setText(textResult);
    ocrResult.setRecognitionTimeRequired(timeRequired);
    return true;
  }

  @Override
  protected void onPostExecute(Boolean result) {
    super.onPostExecute(result);

    Handler handler = activity.getHandler();
    if (handler != null) {
      // Send results for single-shot mode recognition.
      if (result) {
        Message message = Message.obtain(handler, R.id.ocr_decode_succeeded, ocrResult);
        message.sendToTarget();
      } else {
        Message message = Message.obtain(handler, R.id.ocr_decode_failed, ocrResult);
        message.sendToTarget();
      }
      activity.getProgressDialog().dismiss();
    }
    if (baseApi != null) {
      baseApi.clear();
    }
  }
}

错误在于 do 和 while 循环:

do {
          lastBoundingBox = iterator.***getBoundingBox***(PageIteratorLevel.RIL_SYMBOL);
          Rect lastRectBox = new Rect(lastBoundingBox[0], lastBoundingBox[1],
                  lastBoundingBox[2], lastBoundingBox[3]);
          charBoxes.add(lastRectBox);
      } while (iterator.next(PageIteratorLevel.RIL_SYMBOL));
      iterator.***delete***();
      ocrResult.setCharacterBoundingBoxes(charBoxes);

在上面加粗的代码中， getBoundingBox 和 delete 有如下错误:

“未为 ResultIterator 类型定义方法 getBoundingBox(int)”

“未为 ResultIterator 类型定义方法 getBoundingBox(int)”

我尝试了几种方法，但就是无法解决问题。 如果有任何解决方案，请帮助我，非常感谢。

Answer 1

@SebastianRoth 是对的:您使用的预编译库已过时。我建议安装 NDK 并遵循 build instructions对于 OCR 引擎。这将重新编译库，包括它的 getBoundingBox 方法。