Working with Pages Using LEADTOOLS OCR Module - OmniPage Engine

To create and run a program that demonstrates how to add pages to an OCR document using Ltdoc2.h. This program will allow page insertion and to save the inserted page:

  1. Create a new directory in the \Examples\CDLL directory called OCR_Ltdoc2.

  2. Copy everything in the SimpleLoad directory (copy only folders content) into the OCR_Ltdoc2 directory.

  3. Compile the project as it is and run SimpleLoad.exe to familiarize yourself with the basic program.

  4. In the Imports.cpp, add the following lines:

    #if defined(WIN64) 
       #pragma comment(lib, "..\\..\\..\\Lib"L_VER_DESIGNATOR"\\CDLL\\x64\\Ltdoc2_x.lib") 
    #else 
       #pragma comment(lib, "..\\..\\..\\Lib"L_VER_DESIGNATOR"\\CDLL\\Win32\\Ltdoc2_u.lib") 
    #endif // #if defined(WIN64) 
    /* L_VER_DESIGNATOR is a macro that defines the version. For example for version 16 uses LTVXX_CONFIG. To set it in Visual Studio 2005, go to the main menu.  Add in Project->Property->Configuration Properties->C/C++->Preprocessor: WIN32;_DEBUG;LTVXX_CONFIG */ 

  5. Add the following line in StdAfx.h in the OCR_Ltdoc2 directory:

    /* LEADTOOLS main OCR document header file */ 
    #include "..\..\..\include\ltdoc2.h" 
    #include "..\..\..\include\ltdlg.h" 

  6. Define the following global variables in Ezfunc.h in the OCR_Ltdoc2 directory:

    L_HDOC2 hDoc; /* OCR Document handle */ 
    PAGEINFO2 PageInfo; 
    DOC2_LANGIDS LangId[1]; 
    L_BOOL bPageAdded; 
    L_INT nSId; 
    #define IDM_INSERT_PAGE        200 
    #define IDM_SAVE_ADDED_PAGE    300 

  7. Add the following statements in Ezfunc.cpp in the WinMain function as follows:

    1. Add the following before calling InitInstance() statement.
            /* Note that this is a sample key, which will not work in your toolkit. You should replace the sample key */ 
            L_SetLicenseFile (TEXT("MyLicenseFile", TEXT("TestKey")); 
            if (L_Doc2StartUp(&hDoc, NULL) != SUCCESS) 
               return 0; 
       
            L_Doc2CreateSettingsCollection(hDoc, -1, &nSId); 
            L_Doc2SetActiveSettingsCollection(hDoc, nSId); 
    2. Add the following after the GetMessage() loop before return statement.
             L_Doc2DeleteSettingsCollection(hDoc, nSId); 
             L_Doc2ShutDown(&hDoc); 
  8. Edit EZFUNC.RC file in the OCR_Ltdoc2 directory and add the following lines:

    #include "EZFUNC.H" 
    MAIN_MENU   MENU 
    BEGIN 
       MENUITEM "Insert Page"        IDM_INSERT_PAGE 
       MENUITEM "Save Added Page"    IDM_SAVE_ADDED_PAGE 
    END 

  9. In Ezfunc.cpp in InitApplication, change the line:

    wcWindowClass.lpszMenuName = NULL; 

    to:

    wcWindowClass.lpszMenuName = TEXT("MAIN_MENU"); 

  10. In Ezfunc.cpp in MainWndProc, change the line:

    Demos_CombinePath(szImagesDirectory, L_TEXT("Image1.cmp"), szFilename, _countof(szFilename)); 
    To:
    Demos_CombinePath(szImagesDirectory, L_TEXT("ocr1.tif"), szFilename, _countof(szFilename)); 

  11. In Ezfunc.cpp in InitInstance, change the menu parameter (tagged as /* Use the window class menu */) in CreateWindow from NULL to LoadMenu(hInstance, MAKEINTRESOURCE("MAIN_MENU")), /*Main Menu*/

  12. In Ezfunc.cpp under WM_CREATE, add the following code after L_LoadBitmap() if(){}:

    /*After code below*/ 
    nRet = L_LoadBitmap (szFilename, &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
    if (nRet != SUCCESS) 
    { 
       wsprintf (achBuff, TEXT("Error %d loading %s"), nRet, (LPTSTR) szFilename); 
       MessageBox (NULL, achBuff, TEXT("Error"), MB_OK); 
       /* We have an error, so post WM_DESTROY */ 
       PostMessage (hWnd, WM_DESTROY, 0, 0); 
       return (FALSE); 
    } 
     
    /*After code above*/ 
    /*Add code below*/ 
    bPageAdded = FALSE; 

  13. In Ezfunc.cpp after WM_PAINT and before WM_DESTROY, add a new switch statement called WM_COMMAND:

    /*After code below*/ 
    case WM_PAINT: 
    /* Get the handle to the device context */ 
    hdc = BeginPaint (hWnd, &ps); 
    if (LeadBitmap.Flags.Allocated)  /* Do we have an image? */ 
    { 
       if (hpalPaint) /* If we have a paint palette, select it */ 
       { 
          hPalette = SelectPalette (hdc, hpalPaint, TRUE); 
          /* Uncomment this if you do not process WM_QUERYNEWPALETTE */ 
          /* RealizePalette (hdc); */ 
       } 
     
       /* Paint the image */ 
       L_PaintDC (hdc, 
       &LeadBitmap, 
       &rLeadSource,   /* Source rectangle */ 
       NULL,           /* Default source clip area */ 
       &rLeadDest,     /* Destination rectangle */ 
       &ps.rcPaint,    /* Dest clip set by WM_PAINT */ 
       SRCCOPY);       /* Normal Paint */ 
       if (hpalPaint)         /* Return old palette */ 
          SelectPalette (hdc, hPalette, TRUE); 
    } 
     
    EndPaint (hWnd, &ps);     /* Return DC */ 
    return (0); 
    /*After code Above*/ 
    /*Add code below*/ 
    case WM_COMMAND: 
    switch(LOWORD(wParam)) 
    { 
       case IDM_INSERT_PAGE: 
       { 
          nRet = L_Doc2AddPage(hDoc, &LeadBitmap, 1); 
          if (nRet != SUCCESS) 
          { 
             wsprintf (achBuff, TEXT("Error %d adding page at index 0"), nRet); 
             MessageBox (NULL, achBuff, TEXT("Error"), MB_OK); 
             /* We have an error, so post WM_DESTROY */ 
             PostMessage (hWnd, WM_DESTROY, 0, 0); 
             return (FALSE); 
          } 
     
          bPageAdded = TRUE; 
          L_Doc2SetActivePage(hDoc, 0); 
          memset(&PageInfo, 0, sizeof(PAGEINFO2)); 
          nRet = L_Doc2GetPageInfo (hDoc, 0, &PageInfo, sizeof(PAGEINFO2)); 
          if (nRet == SUCCESS) 
          { 
             L_INT nPageCount = 0; 
             L_Doc2GetPageCount(hDoc, &nPageCount); 
             L_Doc2SetActivePage(hDoc, nPageCount - 1); 
             /* Force paint palette creation */ 
             SendMessage (hWnd, WM_QUERYNEWPALETTE, 0, 0L); 
             RedrawWindow(hWnd,0,0,256); 
             wsprintf (achBuff, TEXT("Page Width = %d\nPage Height = %d\nPage Bits Per Pixel = %d\nPages Inserted = %d"), 
             PageInfo.nWidth, 
             PageInfo.nHeight, 
             PageInfo.nBitsPerPixel, 
             nPageCount); 
             MessageBox (NULL, achBuff, TEXT("Pages Info"), MB_OK); 
          } 
     
          LangId[0] = DOC2_LANG_ID_ENGLISH; 
          nRet = L_Doc2SelectLanguages(hDoc, LangId, 1); 
          if (nRet != SUCCESS) 
          { 
             wsprintf (achBuff, TEXT("Error %d Setting English as the default language."), nRet); 
             MessageBox (NULL, achBuff, TEXT("Error"), MB_OK); 
             RemoveDocumentPages(); 
             /* We have an error, so post WM_DESTROY */ 
             PostMessage (hWnd, WM_DESTROY, 0, 0); 
             return (FALSE); 
          } 
       } 
       break; 
     
       case IDM_SAVE_ADDED_PAGE: 
       { 
          L_INT nPageCount=0; 
          L_INT nRet = L_Doc2GetPageCount(hDoc, &nPageCount); 
          if (nRet != SUCCESS) 
          { 
             MessageBox(NULL, TEXT("Cannot get pages count"), TEXT("Error!"), MB_OK); 
             return 0; 
          } 
          if (nPageCount <=0) 
          { 
             MessageBox(NULL, TEXT("No added pages, please add pages first"), TEXT("Error!"), MB_OK); 
             return 0; 
          } 
          BITMAPHANDLE ExportBmp; 
          L_InitBitmap(&ExportBmp, sizeof(BITMAPHANDLE), 0, 0, 1); 
          nRet = L_Doc2ExportPage(hDoc, &ExportBmp, sizeof(BITMAPHANDLE), 0); 
          if (nRet != SUCCESS) 
          { 
             MessageBox(NULL, TEXT("Cannot export page to save"), TEXT("Error!"), MB_OK); 
             return 0; 
          } 
          nRet = L_SaveBitmap(TEXT("c:\\test.tif"), 
          &ExportBmp, 
          FILE_TIF, 
          ExportBmp.BitsPerPixel, 
          0, 
          NULL); 
          L_FreeBitmap(&ExportBmp); 
       } 
       break; 
    } 
     
    return 0; 
    /*Add code above*/ 

  14. Add the following function in EZFUNC.CPP in OCR_Ltdoc2 directory, add it at the end after void CalcDisplay() function:

    void RemoveDocumentPages() 
    { 
       L_INT nPageCount = 0; 
       L_INT i, nRet; 
       L_TCHAR szBuffer[1024]; 
       nRet = L_Doc2GetPageCount(hDoc, &nPageCount); 
       if (nRet == SUCCESS) 
       { 
          for (i=0; i<nPageCount; i++) 
          { 
             L_Doc2CleanupPages(hDoc, TRUE); 
             nRet = L_Doc2RemovePage(hDoc, i); 
             if (nRet == SUCCESS) 
             { 
                wsprintf(szBuffer, TEXT("The page # %d was removed successfully"), i); 
                MessageBox(NULL, szBuffer, TEXT("Notice!"), MB_OK); 
             } 
          } 
       } 
    } 

  15. Also, add the following statement before the MainWndProc function.

    void RemoveDocumentPages(); 

  16. On the Build menu, select Build SimpleLoad.exe.

  17. On the Build menu, select Execute SimpleLoad.exe.

    ✎ NOTE

    Before building project, clean solution and project files. In Build, select Clean Solution and Clean SimpleLoad).

  18. Save this project to use it for testing other code samples.

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LEADTOOLS OCR Module - OmniPage Engine C API Help