Working with Pages Using LEADTOOLS OCR Module - LEAD Engine

To create and run a program that demonstrates how to add pages to an OCR document using Ltocr.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_Ltocr.
2. Copy everything in the SimpleLoad directory (copy only folders content) into the OCR_Ltocr 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\\CDLLVC10\\x64\\Ltocr_x.lib")   
   #pragma comment(lib, "..\\..\\..\\Lib\\CDLLVC10\\Win32\\Ltocr_u.lib")   
#endif // #if defined(WIN64) 

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

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

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

#define IDM_INSERT_PAGE 200   
#define IDM_SAVE_ADDED_PAGE 300   
L_OcrEngine hEngine;                  /* OCR Engine handle */   
L_OcrPage hPage;                      /* OCR Page handle */   
L_OcrDocumentManager hDocumentManager; /* OCR Document Manager handle */   
L_OcrDocument hDocument;              /* OCR Document handle */ 

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

L_SetLicenseFile(TEXT("MyLicenseFile"), TEXT("DeveloperKey"));   
L_INT nRet = L_OcrEngineManager_CreateEngine(L_OcrEngineType_LEAD, &hEngine);   
if(nRet != SUCCESS)   
   return 0;   
nRet = L_OcrEngine_Startup(hEngine, NULL, NULL);   
if(nRet != SUCCESS)   
   return 0;   
nRet = L_OcrEngine_GetDocumentManager(hEngine, &hDocumentManager);   
if(nRet != SUCCESS)   
   return 0;   
nRet = L_OcrDocumentManager_CreateDocument(hDocumentManager, &hDocument, L_OcrCreateDocumentOptions_AutoDeleteFile, NULL);   
if(nRet != SUCCESS)   
   return 0; 

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


9. Edit EZFUNC.RC file in the OCR_Ltocr directory and add the following lines:

#include "EZFUNC.H"   
   MENUITEM "Insert Page"        IDM_INSERT_PAGE   
   MENUITEM "Save Added Page"    IDM_SAVE_ADDED_PAGE   

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

wcWindowClass.lpszMenuName = NULL; 


wcWindowClass.lpszMenuName = TEXT("MAIN_MENU"); 

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

Demos_CombinePath(szImagesDirectory, L_TEXT("Image1.cmp"), szFilename, _countof(szFilename));  


Demos_CombinePath(szImagesDirectory, L_TEXT("ocr1.tif"), szFilename, _countof(szFilename)); 

12. 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*/ 

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, 
   &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 */ 
      // Create the OCR page from the loaded bitmap 
      nRet = L_OcrPage_FromBitmap(hEngine, &hPage, &LeadBitmap, L_OcrBitmapSharingMode_AutoFree, NULL, NULL); 
      if (nRet != SUCCESS) 
         MessageBox (NULL, TEXT("Error creating OCR page"), TEXT("Error"), MB_OK); 
         /* We have an error, so post WM_DESTROY */ 
         PostMessage (hWnd, WM_DESTROY, 0, 0); 
         return (FALSE); 
      // Add the created OCR page into the file-based OCR document 
      nRet = L_OcrDocument_AddPage(hDocument, hPage); 
      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); 
      /* Force paint palette creation */ 
      SendMessage (hWnd, WM_QUERYNEWPALETTE, 0, 0L); 
      wsprintf (achBuff, TEXT("Page Width = %d\nPage Height = %d\nPage Bits Per Pixel = %d\n"), 
      MessageBox (NULL, achBuff, TEXT("Page Info"), MB_OK); 
      BITMAPHANDLE ExportBmp; 
      L_InitBitmap(&ExportBmp, sizeof(BITMAPHANDLE), 0, 0, 1); 
      nRet = L_OcrPage_GetBitmap(hPage, L_OcrPageBitmapType_Original, &ExportBmp, sizeof(BITMAPHANDLE)); 
      if (nRet != SUCCESS) 
         MessageBox(NULL, TEXT("Cannot retrieve page bitmap to save"), TEXT("Error!"), MB_OK); 
         return 0; 
      L_TCHAR szFileName[MAX_PATH] = {0}; 
      lstrcpy(szFileName, TEXT("c:\\test.tif")); 
      nRet = L_SaveBitmap(szFileName, ExportBmp, FILE_TIF, ExportBmp.BitsPerPixel, 0, NULL); 
      if(nRet != SUCCESS) 
         wsprintf (achBuff, TEXT("Error %d saving OCR page bitmap to %s"), nRet, szFileName); 
         MessageBox(NULL, achBuff, TEXT("Error!"), MB_OK); 
         return 0; 
         wsprintf (achBuff, TEXT("OCR page bitmap was saved to %s"), szFileName); 
         MessageBox(NULL, achBuff, TEXT("Error!"), MB_OK); 
         return 0; 
return 0; 
/*Add code above*/ 

14. Delete or comment out the following lines from WM_DESTROY message since L_OcrPage_Destroy call will free the bitmap since the OCR page owns the bitmap handle and you don't own it any more and this is because we passed L_OcrBitmapSharingMode_AutoFree for the sharingMode parameter of the L_OcrPage_FromBitmap function.

/* Free the image, if there is one */   
if (LeadBitmap.Flags.Allocated)   
   L_FreeBitmap (&LeadBitmap); 

15. On the Build menu, select Build SimpleLoad.exe.
16. 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. 17. Save this project to use it for testing other code samples.

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