l_invertedpagebitmap

#include "l_bitmap.h"

L_LTIMGCOR_API L_INT EXT_FUNCTION L_InvertedPageBitmap(pBitmap, bIsInverted, uFlags)

pBITMAPHANDLE pBitmap;	/* pointer to the bitmap handle */
L_BOOL * bIsInverted;	/* address of the variable to be updated */
L_UINT uFlags;	/* flags */

Detects if the image (page) is inverted (white text and black background), and invert it if it is not.

Parameter	Description
pBitmap	Pointer to the bitmap handle that references the bitmap.
bIsInverted	Address of the variable to be updated with the detection result. Possible values are:
	Value	Meaning
	TRUE	The image is inverted.
	FALSE	The image is not inverted.
uFlags	Flags that indicate whether to invert the image. Possible values are:
	Value	Meaning
	INVERTEDPAGE_PROCESS	[0x00000000] Invert the image.
	INVERTEDPAGE_NOPROCESS	[0x00000001] Don't invert the image. Generally this flag is used to find whether the image is inverted.

Returns

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

Comments

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.

If uFlags contains INVERTEDPAGE_NOPROCESS, the function will update bIsInverted with the result, without inverting the image.

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

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 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

Win32, x64.

See Also

Functions:	L_DespeckleBitmap, L_BlankPageDetectorBitmap
Topics:	Raster Image Functions: Filtering Images
	Raster Image Functions: Document Imaging
	Processing an Image

Example

#define MAKE_IMAGE_PATH(pFileName) TEXT("C:\\Users\\Public\\Documents\\LEADTOOLS Images\\")pFileName


#if defined (LEADTOOLS_V16_OR_LATER)
L_INT InvertedPageBitmapExample(L_VOID)
{
   L_INT nRet;
   BITMAPHANDLE LeadBitmap;   /* Bitmap handle to hold the loaded image. */
   L_BOOL IsInverted; /* the boolean  that will hold the value of (Is the page inverted or not) */
   /* Load the bitmap, keeping the bits per pixel of the file */
   nRet = L_LoadBitmap (MAKE_IMAGE_PATH(TEXT("OCR1.TIF")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL);
   if(nRet !=SUCCESS)
      return nRet;

   nRet = L_InvertedPageBitmap(&LeadBitmap, &IsInverted, INVERTEDPAGE_PROCESS);
   if(nRet !=SUCCESS)
      return nRet;

   nRet = L_SaveBitmap(MAKE_IMAGE_PATH(TEXT("Result.BMP")), &LeadBitmap, FILE_BMP, 24, 0, NULL);
   if(nRet !=SUCCESS)
      return nRet;
   //free bitmap 
   if(LeadBitmap.Flags.Allocated)  
      L_FreeBitmap(&LeadBitmap);  
   return SUCCESS;
}
#endif // LEADTOOLS_V16_OR_LATER