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:

Create a new directory in the \Examples\CDLL directory called OCR_Ltdoc2.
Copy everything in the SimpleLoad directory (copy only folders content) into the OCR_Ltdoc2 directory.
Compile the project as it is and run SimpleLoad.exe to familiarize yourself with the basic program.

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 */

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"

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

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

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);

Add the following after the GetMessage() loop before return statement.

       L_Doc2DeleteSettingsCollection(hDoc, nSId); 
       L_Doc2ShutDown(&hDoc);

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

In Ezfunc.cpp in InitApplication, change the line:

wcWindowClass.lpszMenuName = NULL;

to:

wcWindowClass.lpszMenuName = TEXT("MAIN_MENU");

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));

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*/

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;

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*/

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); 
         } 
      } 
   } 
}

Also, add the following statement before the MainWndProc function.
```
void RemoveDocumentPages(); 
```
On the Build menu, select Build SimpleLoad.exe.
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).
Save this project to use it for testing other code samples.

Download our FREE evaluation

Help Version 20.0.2020.4.2

LEADTOOLS OCR Module - OmniPage Engine C API Help

Introduction

Version History

Getting Started with LEADTOOLS Character Recognition

Redistributables/Files To Be Included With Your Application

LEADTOOLS OCR Module - OmniPage Engine Features

LEADTOOLS ICR Add-On

LEADTOOLS OMR Add-On

LEADTOOLS PDF OCR Add-On

Quick Reference

Tutorials

Function References