#include "l_bitmap.h"

L_LTIMGCOR_API L_INT EXT_FUNCTION L_InvertedPageBitmap(pBitmap, bIsInverted, uFlags)


pointer to the bitmap handle

L_BOOL * bIsInverted;

address of a variable to be updated

L_UINT uFlags;


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

Parameter Description
pBitmap Pointer to the bitmap handle that references the bitmap.
bIsInverted Address of a 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 and how to do it. Possible values are:
  Value Meaning
  INVERTEDPAGE_PROCESS [0x00000000] Invert the image.
  INVERTEDPAGE_NOPROCESS [0x00000001] Do not invert the image. Generally this flag is used to find whether the image is inverted.
INVERTEDPAGE_EXCLUDE_BORDER [0x00000002] Excludes White or Black borders from the calculations.
INVERTEDPAGE_USE_ZONES [0x00000004] An advanced version that is able to detect figure images before inverting them. This option is slower than the other options. This flag cannot be used with INVERTEDPAGE_EXCLUDE_BORDER.



The function was successful.

< 1

An error occurred. Refer to Return Codes.


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


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


Win32, x64, Linux.

See Also


L_DespeckleBitmap, L_BlankPageDetectorBitmap, L_AutoLineRemove


Raster Image Functions: Filtering Images


Raster Image Functions: Document Imaging


Processing an Image


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  
   return SUCCESS; 
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