L_OcrPage_GetBitmap (original) (raw)

Summary

Gets the original or processing bitmap data of this page as a bitmap handle.

Syntax

#include "ltocr.h"

L_LTOCR_API L_INT EXT_FUNCTION L_OcrPage_GetBitmap(page, bitmapType, bitmapHandle, bitmapHandleSize)

Parameters

L_OcrPage page

Handle to the OCR page.

L_OcrPageBitmapType bitmapType

The page type to get.

BITMAPHANDLE* bitmapHandle

Address to BITMAPHANDLE variable to be updated with the page bitmap.

L_UINT bitmapHandleSize

Size of the BITMAPHANDLE structure, use sizeof(BITMAPHANDLE).

Returns

Comments

Each L_OcrPage contains two versions of the image used to create it: an original and an optional processing version. The processing version usually black/white and has uniform resolution (if the original image is FAX for example) and it gets passed to the internal OCR engine during the zoning and recognition process. The L_OcrPage_AutoPreprocess method also uses the B/W image to determine if the page is inverted, skewed, or has an orientation. However, it applies the correction to both the current and processing images.

You can use L_OcrPage_GetBitmap to get a copy of the processing image, but as for the original image this function returns a reference to the original bitmap handle (not a copy) so you should not call L_FreeBitmap on this bitmap type.

You cannot set the processing image of a page; it is created automatically by the engine.

If the original image is black and white and has uniform vertical and horizontal resolution, then the engine will not create a processing image, in other words, L_OcrPage_GetBitmap will return identical BITMAPHANDLE for both original and processing bitmap types.

If the original image has different horizontal and vertical resolution, such as a FAX image, the processing page will be have be resized to have uniform resolution.

Required DLLs and Libraries

• LTOCR
• For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

See Also

Functions

• L_OcrPage_Destroy
• L_OcrPage_FromBitmap
• L_OcrPage_SetBitmap
• L_OcrPage_GetOverlayBitmap
• L_OcrPage_SetOverlayBitmap
• L_OcrPage_SetBitmapChangedCallback
• L_OcrPage_IsInverted
• L_OcrPage_GetRotateAngle
• L_OcrPage_GetDeskewAngle
• L_OcrPage_AutoPreprocess
• L_OcrPage_AutoZone
• L_OcrPage_GetZoneCount
• L_OcrPage_InsertZone
• L_OcrPage_AddZone
• L_OcrPage_IndexOfZone
• L_OcrPage_GetZoneAt
• L_OcrPage_SetZoneAt
• L_OcrPage_RemoveZone
• L_OcrPage_RemoveZoneAt
• L_OcrPage_ClearZones
• L_OcrPage_GetZoneCells
• L_OcrPage_SetZoneCells
• L_OcrPage_HitTestZone
• L_OcrPage_IsRecognized
• L_OcrPage_Recognize
• L_OcrPage_Unrecognize
• L_OcrPage_GetRecognizeStatistics
• L_OcrPage_GetRecognizedCharacters
• L_OcrPage_SetRecognizedCharacters
• L_OcrPage_FreePageCharacters
• L_OcrPage_GetZoneWords
• L_OcrPage_FreeWords
• L_OcrPage_GetText
• L_OcrPage_ExtractZoneMICRData
• L_OcrPage_DetectLanguages
• L_OcrPage_LoadZonesFile
• L_OcrPage_SaveZonesFile
• L_OcrPage_SaveXml
• L_OcrPage_GetAutoPreprocessValues

Topics

• Programming with LEADTOOLS OCR Module - LEAD Engine
• Starting and Shutting Down the OCR Engine
• Recognizing OCR Pages
• Working With OCR Pages

Example

L_INT L_OcrPage_GetBitmapExample() { int bitsPerPixel = 0; int qualityFactor = 2; L_OcrEngine ocrEngine = NULL; L_OcrPage ocrPage = NULL; BITMAPHANDLE bitmap = {0}, exportPage = {0}; pLOADFILEOPTION loadOpts = NULL; pSAVEFILEOPTION saveOpts = NULL; pFILEINFO fileInfo = NULL; L_OcrProgressCallback callback = NULL; L_VOID* userData = NULL; // Create an instance of the engine L_INT retCode = L_OcrEngineManager_CreateEngine(L_OcrEngineType_LEAD, &ocrEngine); if(retCode != SUCCESS) return retCode; // Start the engine using default parameters retCode = L_OcrEngine_Startup(ocrEngine, NULL, OCR_LEAD_RUNTIME_DIR); if(retCode != SUCCESS) goto CLEANUP; // Load an image file retCode = L_LoadBitmap(MAKE_IMAGE_PATH(L_TEXT("Ocr1.tif")), &bitmap, sizeof(BITMAPHANDLE), bitsPerPixel, ORDER_RGB, loadOpts, fileInfo); if(retCode != SUCCESS) goto CLEANUP; // Add the raster image into the OCR page retCode = L_OcrPage_FromBitmap(ocrEngine, &ocrPage, &bitmap, L_OcrBitmapSharingMode_AutoFree, callback, userData); if(retCode != SUCCESS) { L_FreeBitmap(&bitmap); goto CLEANUP; } // At this point, we have a valid page and bitmap ownership has transfered, so, we do not need to free the bitmap anymore bitmap.Flags.Allocated = 0; retCode = L_OcrPage_GetBitmap(ocrPage, L_OcrPageBitmapType_Original, &exportPage, sizeof(BITMAPHANDLE)); if(retCode != SUCCESS) goto CLEANUP; // Save this image to disk bitsPerPixel = 24; L_SaveBitmap(MAKE_IMAGE_PATH(L_TEXT("OcrExported.jpg")), &exportPage, FILE_JPEG, bitsPerPixel, qualityFactor, saveOpts); CLEANUP: if(ocrPage != NULL) L_OcrPage_Destroy(ocrPage); if(L_OcrEngine_IsStarted(ocrEngine)) L_OcrEngine_Shutdown(ocrEngine); L_OcrEngine_Destroy(ocrEngine); return retCode; }