How to read text from an image using OCR in android

Question

I want to implement OCR in Android. I.e. getting texts from a business card image. I used code from here.

But when I run this code I got the following error:

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

I think it points to the following line:

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

of the OCRServiceAPI class. How can I fix this?

Answer 1

Checkout that whether you are getting correct path of the image which are selecting from the gallery.

I have also tried this demo and its working fine for me.

Here I'm posting my code:

• 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 2

Can't guess about your above error but I have done this task in Blackberry by using third party application ABBYY product of OCR on PHP server.

During my long R & D I have also worked on the below link of Github_Abbyy. For using this code you should create a free account here: ocrsdk.com

Answer 3

Not all the Apache packages are available by default in Android, so you will have to download them from the Apache repositories and include those yourself. See the question Android libraries not found and the links provided in the answer there.

Edit: Specifically the sub-packages of org.apache.http.entity are not included, only the entity package itself.

In the example project given by the OCR API they have placed the mime package in a jar in the lib folder.