l_autozonebitmap

L_AutoZoneBitmap

#include "l_bitmap.h"

L_LTIMGCOR_API L_INT EXT_FUNCTION L_AutoZoneBitmap(pBitmap, phZones, puCount, uFlags, pCallback, pUserData)

pBITMAPHANDLE pBitmap;	/* pointer to the bitmap handle */
HGLOBAL * phZones;	/* pointer of a handle to be updated with the detected zones */
L_UINT32 * puCount;	/* the count of detected zones */
L_UINT32 uFlags;	/* flags */
AUTOZONECALLBACK pCallback;	/* optional callback function */
L_VOID * pUserData;	/* pointer to more parameters for the callback */

Detects different zone types (Text, Graphic and Table) in an image automatically. This is an important feature for OCR pre-processing to improve the recognition results. This function is useful for any application that needs to automatically separate images, tables and text within mixed raster content (MRC) images.

Parameter	Description
pBitmap	Pointer to the bitmap handle referencing the bitmap in which the zones will be detected.
phZones	Pointer to a handle to be updated with the detected zones. To retrieve data of the detected zones cast the phZones to pLEADZONE and call GlobalLock function.
puCount	Pointer to a variable to be updated with the number of detected zones.
uFlags	Flags that indicate the detection behavior of the function. The following flags indicate the type of zones to be detected. You can combine values when appropriate by using a bitwise OR ( \| ). Possible values are:
	Value	Meaning
	AUTOZONE_DETECT_TEXT	[0x0001] Detects text zones.
	AUTOZONE_DETECT_GRAPHIC	[0x0002] Detects graphic zones.
	AUTOZONE_DETECT_TABLE	[0x0004] Detects table zones.
	AUTOZONE_DETECT_ALL	[0x0007] Detects all zone types (Text, Graphics and tables).
	Flags indicate whether to allow overlapping among zones:
	Value	Meaning
	AUTOZONE_DONT_ALLOW_OVERLAP	[0x0000] Dont allow zones to overlap.
	AUTOZONE_ALLOW_OVERLAP	[0x0010] Allow zones to overlap.
	Flags indicate the merging type among text zones:
	Value	Meaning
	AUTOZONE_ACCURATE_ZONES	[0x0000] Dont merge text zones and keep them separated (paragraphs).
	AUTOZONE_GENERAL_ZONES	[0x0100] Merge text zones to the maximum.
	Flags indicate the table zones detection options:
	Value	Meaning
	AUTOZONE_DONT_RECOGNIZE_ONE_CELL_TABLE	[0x0000] Ignore one-cell tables (borders), and detect what inside.
	AUTOZONE_RECOGNIZE_ONE_CELL_TABLE	[0x1000] Consider borders as one-cell tables.
	Flags indicate whether to use multi-threading:
	Value	Meaning
	AUTOZONE_USE_MULTITHREADING	[0x00000000] Use multi-threading (that will be faster with a multi-core CPUs).
	AUTOZONE_DONTUSE_MULTITHREADING	[0x80000000] Dont Use multi-threading (that will be used with a single-core CPUs)
pCallback	Optional callback function for additional processing.
	If you do not provide a callback function, use NULL as the value of this parameter.
	If you do provide a callback function, use the function pointer as the value of this parameter.
	The callback function must adhere to the function prototype described in AUTOZONECALLBACK Function.
pUserData	Void pointer that you can use to pass one or more additional parameters that the callback function needs.
	To use this feature, assign a value to a variable or create a structure that contains as many fields as you need. Then, in this parameter, pass the address of the variable or structure, casting it to L_VOID . The callback function, which receives the address in its own pUserData* parameter, can cast it to a pointer of the appropriate data type to access your variable or structure.
	If the additional parameters are not needed, you can pass NULL in this parameter.

Returns

SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

After using this function the phZones should be freed using the L_FreeZoneData function.

To update a status bar or detect a user interrupt during execution of this function, see the L_SetStatusCallback function.

This function does not support 12 and 16-bit grayscale and 48 and 64-bit color images. If the image is 12 and 16-bit grayscale and 48 and 64-bit color, the function will not return an error.

This function does not support signed data images. It returns the error code ERROR_SIGNED_DATA_NOT_SUPPORTED if a signed data image is passed to this function.

This function does not support 32-bit grayscale images. It returns the error code ERROR_GRAY32_UNSUPPORTED if a 32-bit grayscale image is passed to this function.

Required DLLs and Libraries

LTIMGCOR

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

Platforms

Windows 95 / 98 / Me, Windows 2000 / XP

See Also

Functions:	L_FreeZoneData, L_DespeckleBitmap, L_WindowLevel, L_ApplyTransformationParameters, L_GetMarksCenterMassBitmap, L_GetTransformationParameters, L_IsRegMarkBitmap, L_SearchRegMarksBitmap
Topics:	Raster Image Functions: Document Imaging
	Raster Image Functions: Processing an Image
	Processing an Image

Example

Detects the image zones and return the results.

 L_INT AutoZoneBitmapExample(L_VOID)
{
   L_INT nRet;
   BITMAPHANDLE LeadBitmap;   /* Bitmap handle to hold the loaded image. */
   HGLOBAL pointer = NULL;
   L_UINT32 count;
   L_INT TextZonesCount = 0;
   L_INT GraphicZonesCount = 0;
   L_INT TableZonesCount = 0;
   L_INT CellsCount = 0;
   L_UINT i;

   nRet = L_LoadBitmap (TEXT("C:\\Program Files\\LEAD Technologies\\LEADTOOLS 16\\Images\\Clean.tif"), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL);
   if(nRet !=SUCCESS)
      return nRet;

   nRet = L_AutoZoneBitmap(
      &LeadBitmap,
      &pointer,
      &count,
      0,
      NULL,
      NULL);

   if(nRet !=SUCCESS)
      return nRet;


   LEADZONE * pZone = (LEADZONE *)GlobalLock(pointer);

   for(i=0; i<count; i++)
   {
      if (pZone[i].uZoneType == LEAD_ZONE_TYPE_TEXT)
      {
         TextZonesCount++;
      }
      if (pZone[i].uZoneType == LEAD_ZONE_TYPE_GRAPHIC)
      {
         GraphicZonesCount++;
      }
      if (pZone[i].uZoneType == LEAD_ZONE_TYPE_TABLE)
      {
         TableZonesCount++;
         TABLEZONE * pTable = (TABLEZONE *)GlobalLock(pZone[i].pZoneData);
         CellsCount = pTable->Rows * pTable->Columns;
         GlobalUnlock(pTable);
      }
   }       

   nRet = L_FreeZoneData(pointer, count);

   if(nRet !=SUCCESS)
      return nRet;

   GlobalUnlock(pointer);

   if(LeadBitmap.Flags.Allocated)  
      L_FreeBitmap(&LeadBitmap); 

   return SUCCESS;
}