#include "ltocr.h"
L_LTOCR_API L_INT EXT_FUNCTION L_OcrZoneManager_GetOMROptions(zoneManager, value)
Gets the OMR options currently used by the engine.
Handle to the OCR engine zone manager.
Address to variable of type L_OcrOMROptions structure to be updated with the OMR options.
Value | Meaning |
---|---|
SUCCESS | The function was successful. |
< 1 | An error occurred. Refer to Return Codes. |
Gets the OMR options currently used by the engine.
OMR stands for Optical Mark Recognition. For more information refer to Using Using OMR in LEADTOOLS C API OCR.
With the L_OcrOMROptions, you can change the following OMR settings:
The OMR zones of a page have the L_OcrZone.ZoneType property set to L_OcrZoneType_OMR.
Currently LEADTOOLS OCR Module - LEAD Engine does not supports auto detection of OMR zones. Instead, you need to: add the OMR zones manually to the page by setting their boundary (through L_OcrZone.Bounds, the zone type through L_OcrZone.ZoneType and adding the zone to the page using the L_OcrPage_AddZone or L_OcrPage_InsertZone before calling L_OcrPage_Recognize.
To use OMR in LEADTOOLS, you need a special key to unlock the OMR capabilities. For more information, refer to Setting a Runtime License.
Required DLLs and Libraries
static void LogMessage(const wchar_t* message, ...)
{
const unsigned int bufferSize = 1024 * 4;
wchar_t buffer[bufferSize];
if(message != NULL)
{
va_list ap;
va_start(ap, message);
vswprintf_s(buffer, message, ap);
va_end(ap);
}
else
{
wcscpy_s(buffer, L"");
}
_tprintf(buffer);
}
L_INT L_OcrZoneManager_GetOMROptionsExample()
{
BITMAPHANDLE bitmap = { 0 };
L_OcrEngine ocrEngine = NULL;
L_OcrPage ocrPage = NULL;
L_OcrZoneManager zoneManager = NULL;
L_OcrDocumentManager ocrDocumentManager = NULL;
L_OcrDocument ocrDocument = NULL;
L_OcrOMROptions omrOptions = {0};
omrOptions.StructSize = sizeof(L_OcrOMROptions);
// Create an instance of the engine
L_INT retCode = L_OcrEngineManager_CreateEngine(L_OcrEngineType_Advantage, &ocrEngine);
if(retCode != SUCCESS)
return retCode;
// Start the engine using default parameters
L_OcrEngine_Startup(ocrEngine, NULL, OCR_ADVANTAGE_RUNTIME_DIR);
L_OcrEngine_GetZoneManager(ocrEngine, &zoneManager);
// Load an image to process
L_LoadBitmap(MAKE_IMAGE_PATH(L_TEXT("Mixed.tif")), &bitmap, sizeof(BITMAPHANDLE), 0, ORDER_RGB, NULL, NULL);
// Add the image to an OCR page
L_OcrPage_FromBitmap(ocrEngine, &ocrPage, &bitmap, L_OcrBitmapSharingMode_AutoFree, NULL, NULL);
// Transfer ownership to the OCR page
bitmap.Flags.Allocated = 0;
// Add the OMR zones. We calculated the 3 OMR zone boundaries for this image previously
L_RECT omrBounds[3] =
{
{ 484, 98, 84, 78 },
{ 494, 184, 70, 54 },
{ 498, 244, 76, 76 }
};
for(L_UINT i = 0; i < _countof(omrBounds); i++)
{
// Create a new OMR zone and add it to the page
L_OcrZone zone = {0};
L_OcrZone_Default(&zone);
zone.ZoneType = L_OcrZoneType_OMR;
zone.Bounds = omrBounds[i];
L_OcrPage_AddZone(ocrPage, &zone);
}
// Change the OMR options (Auto detection of frames with highest sensitivity)
L_OcrZoneManager_GetOMROptions(zoneManager, &omrOptions);
omrOptions.FrameDetectionMethod = L_OcrOMRFrameDetectionMethod_Auto;
omrOptions.Sensitivity = L_OcrOMRSensitivity_Highest;
L_OcrZoneManager_SetOMROptions(zoneManager, &omrOptions);
// Recognize the page
L_OcrPage_Recognize(ocrPage, NULL, NULL);
// Now show the OMR zone properties
L_UINT count = 0;
L_OcrPage_GetZoneCount(ocrPage, &count);
for (L_UINT i = 0; i < count; i++)
{
L_OcrPageCharacters pageCharacters = {0};
pageCharacters.StructSize = sizeof(L_OcrPageCharacters);
L_INT nRet = L_OcrPage_GetRecognizedCharacters(ocrPage, &pageCharacters);
if(nRet == SUCCESS)
{
if(pageCharacters.ZoneCharacterCount > 0)
{
L_OcrCharacter omrCharacter = pageCharacters.ZoneCharacters[i].Characters[0];
LogMessage(L"%u: State: %s, Confidence: %u", i + 1, omrCharacter.Code == omrOptions.StateRecognitionCharacters[1] ? L"Filled" : L"Unfilled", omrCharacter.Confidence);
}
// We should free the page characters
L_OcrPage_FreePageCharacters(&pageCharacters);
}
}
// Now save the result as PDF using the default characters representation for OMR states (0 for unfilled, 1 for filled)
L_TCHAR* pdfFileName1 = MAKE_IMAGE_PATH(L_TEXT("Omr_Results1.pdf"));
LogMessage(L"Saving to %s", pdfFileName1);
//Create an OCR document
L_OcrEngine_GetDocumentManager(ocrEngine, &ocrDocumentManager);
L_OcrDocumentManager_CreateDocument(ocrDocumentManager, &ocrDocument, L_OcrCreateDocumentOptions_AutoDeleteFile, NULL);
//Add OCR Page to OCR document
L_OcrDocument_AddPage(ocrDocument, ocrPage);
L_OcrDocument_Save(ocrDocument, pdfFileName1, DOCUMENTFORMAT_PDF, NULL, NULL);
// Change the character representation for the OMR states to Y for unfilled, and X for filled
omrOptions.StateRecognitionCharacters[0] = 'Y';
omrOptions.StateRecognitionCharacters[1] = 'X';
L_OcrZoneManager_SetOMROptions(zoneManager, &omrOptions);
L_TCHAR* pdfFileName2 = MAKE_IMAGE_PATH(L_TEXT("Omr_Results2.pdf"));
LogMessage(L"Saving to %s", pdfFileName2);
L_OcrDocument_Save(ocrDocument, pdfFileName2, DOCUMENTFORMAT_PDF, NULL, NULL);
//CLEANUP
if(bitmap.Flags.Allocated)
L_FreeBitmap(&bitmap);
if(ocrPage != NULL)
L_OcrPage_Destroy(ocrPage);
if(ocrDocument != NULL)
L_OcrDocument_Destroy(ocrDocument);
if(ocrEngine != NULL)
L_OcrEngine_Destroy(ocrEngine);
return SUCCESS;
}