android - 如何在android中使用OCR从图像中读取文本

Question

我想在 Android 中实现 OCR。即从名片图像中获取文本。我使用了这里的代码。

但是当我运行这段代码时，我得到了以下错误：

java.lang.NoClassDefFoundError: org.apache.http.entity.mime.content.FileBody

我认为它指向以下行：

final FileBody image = new FileBody(new File(filePath));

类的OCRServiceAPI。我怎样才能解决这个问题？

Answer 1

无法猜测您的上述错误，但我通过在PHP服务器上使用OCR 的第三方应用程序ABBYY产品在Blackberry中完成了此任务。

在我长期的 R & DI 期间，我还研究了Github_Abbyy的以下链接。要使用此代码，您应该在此处创建一个免费帐户：ocrsdk.com

Answer 2

检查您是否获得了从图库中选择的图像的正确路径。

我也试过这个演示，它对我来说很好用。

在这里我发布我的代码：

• OCRServiceAPI.java

  public class OCRServiceAPI {  
  public final String m_serviceUrl = "http://api.ocrapiservice.com/1.0/rest/ocr";
  private final String m_paramImage = "image";
  private final String m_paramLanguage = "language";
  private final String m_paramApiKey = "apikey";
  private String m_apiKey, m_responseText;
  private int m_responseCode; 
  public OCRServiceAPI(final String p_apiKey) {
      this.m_apiKey = p_apiKey;
  }
  /*
   * Convert image to text.
   * 
   * @param language The image text language.
   * 
   * @param filePath The image absolute file path.
   * 
   * @return true if everything went okay and false if there is an error with
   * sending and receiving data.
   */
  public boolean convertToText(final String p_language,
          final String p_filePath) {
      try {
          sendImage(p_language, p_filePath);
          return true;
      } catch (ClientProtocolException e) {
          e.printStackTrace();
          return false;
      } catch (IOException e) {
          e.printStackTrace();
          return false;
      }
  }
  /*
   * Send image to OCR service and read response.
   * 
   * @param language The image text language.
   * 
   * @param filePath The image absolute file path.
   */
  private void sendImage(final String p_language, final String p_filePath)
          throws ClientProtocolException, IOException {
      final HttpClient m_httpclient = new DefaultHttpClient();
      final HttpPost m_httppost = new HttpPost(m_serviceUrl);
      final FileBody m_image = new FileBody(new File(p_filePath));
      final MultipartEntity m_reqEntity = new MultipartEntity();
      m_reqEntity.addPart(m_paramImage, m_image);
      m_reqEntity.addPart(m_paramLanguage, new StringBody(p_language));
      m_reqEntity.addPart(m_paramApiKey, new StringBody(getApiKey()));
      m_httppost.setEntity(m_reqEntity);
      final HttpResponse m_response = m_httpclient.execute(m_httppost);
      final HttpEntity m_resEntity = m_response.getEntity();
      final StringBuilder m_sb = new StringBuilder();
      if (m_resEntity != null) {
          final InputStream m_stream = m_resEntity.getContent();
          byte m_bytes[] = new byte[4096];
          int m_numBytes;
          while ((m_numBytes = m_stream.read(m_bytes)) != -1) {
              if (m_numBytes != 0) {
                  m_sb.append(new String(m_bytes, 0, m_numBytes));
              }
          }
      }
      setResponseCode(m_response.getStatusLine().getStatusCode());
      setResponseText(m_sb.toString());
  }
  public int getResponseCode() {
      return m_responseCode;
  }
  public void setResponseCode(int p_responseCode) {
      this.m_responseCode = p_responseCode;
  }
  public String getResponseText() {
      return m_responseText;
  }
  public void setResponseText(String p_responseText) {
      this.m_responseText = p_responseText;
  }
  public String getApiKey() {
      return m_apiKey;
  }
  public void setApiKey(String p_apiKey) {
      this.m_apiKey = p_apiKey;
  }   }
  

• SampleActivity.java

  public class SampleActivity extends Activity implements OnClickListener {
  private final int RESPONSE_OK = 200;
  private final int IMAGE_PICKER_REQUEST = 1;
  private TextView m_tvPicNameText;
  private EditText m_etLangCodeField, m_etApiKeyFiled;
  private String m_apiKey; // T7GNRh7VmH
  private String m_langCode; // en
  private String m_fileName;
  @Override
  public void onCreate(Bundle p_savedInstanceState) {
      super.onCreate(p_savedInstanceState);
      getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
              WindowManager.LayoutParams.FLAG_FULLSCREEN);
      setContentView(R.layout.main);
      m_tvPicNameText = (TextView) findViewById(R.id.imageName);
      m_etLangCodeField = (EditText) findViewById(R.id.lanuageCode);
      m_etApiKeyFiled = (EditText) findViewById(R.id.apiKey);
      m_etApiKeyFiled.setText("T7GNRh7VmH");
      final Button m_btnPickImage = (Button) findViewById(R.id.picImagebutton);
      m_btnPickImage.setOnClickListener(new OnClickListener() {
          public void onClick(View v) {
              // Starting image picker activity
              startActivityForResult(
                      new Intent(
                              Intent.ACTION_PICK,
                              android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI),
                      IMAGE_PICKER_REQUEST);
          }
      });
      final Button m_btnConvertText = (Button) findViewById(R.id.convert);
      m_btnConvertText.setOnClickListener(this);
  }
  public void onClick(View p_v) {
      m_apiKey = m_etApiKeyFiled.getText().toString();
      m_langCode = m_etLangCodeField.getText().toString();
      // Checking are all fields set
      if (m_fileName != null && !m_apiKey.equals("")
              && !m_langCode.equals("")) {
          final ProgressDialog m_prgDialog = ProgressDialog.show(
                  SampleActivity.this, "Loading ...", "Converting to text.",
                  true, false);
          final Thread m_thread = new Thread(new Runnable() {
              public void run() {
                  final OCRServiceAPI m_apiClient = new OCRServiceAPI(
                          m_apiKey);
                  m_apiClient.convertToText(m_langCode, m_fileName);
                  // Doing UI related code in UI thread
                  runOnUiThread(new Runnable() {
                      public void run() {
                          m_prgDialog.dismiss();
                          // Showing response dialog
                          final AlertDialog.Builder m_alert = new AlertDialog.Builder(
                                  SampleActivity.this);
                          m_alert.setMessage(m_apiClient.getResponseText());
                          m_alert.setPositiveButton("OK",
                                  new DialogInterface.OnClickListener() {
                                      public void onClick(
                                              DialogInterface p_dialog,
                                              int p_id) {
                                      }
                                  });
                          // Setting dialog title related from response code
                          if (m_apiClient.getResponseCode() == RESPONSE_OK) {
                              m_alert.setTitle("Success");
                          } else {
                              m_alert.setTitle("Faild");
                          }
                          m_alert.show();
                      }
                  });
              }
          });
          m_thread.start();
      } else {
          Toast.makeText(SampleActivity.this, "All data are required.",
                  Toast.LENGTH_SHORT).show();
      }
  }
  @Override
  protected void onActivityResult(int p_requestCode, int p_resultCode,
          Intent p_data) {
      super.onActivityResult(p_requestCode, p_resultCode, p_data);
      if (p_requestCode == IMAGE_PICKER_REQUEST && p_resultCode == RESULT_OK) {
          m_fileName = getRealPathFromURI(p_data.getData());
          m_tvPicNameText.setText("Selected: en"
                  + getStringNameFromRealPath(m_fileName));
      }
  }
  /*
   * Returns image real path.
   */
  private String getRealPathFromURI(final Uri p_contentUri) {
      final String[] m_proj = { MediaStore.Images.Media.DATA };
      final Cursor m_cursor = managedQuery(p_contentUri, m_proj, null, null,
              null);
      int m_columnIndex = m_cursor
              .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
      m_cursor.moveToFirst();
      return m_cursor.getString(m_columnIndex);
  }
  /*
   * Cuts selected file name from real path to show in screen.
   */
  private String getStringNameFromRealPath(final String bucketName) {
      return bucketName.lastIndexOf('/') > 0 ? bucketName
              .substring(bucketName.lastIndexOf('/') + 1) : bucketName;
  }   }
  

Answer 3

默认情况下，并非所有 Apache 软件包都在 Android 中可用，因此您必须从 Apache 存储库下载它们并自己包含它们。请参阅问题Android library not found以及答案中提供的链接。

编辑：具体不包括 org.apache.http.entity 的子包，只包括实体包本身。

在 OCR API 给出的示例项目中，他们将 mime 包放在lib 文件夹中的 jar 中。