#include "l_bitmap.h"

L_LTIMGCLR_API L_INT L_SegmentBitmap(pBitmap, uThreshold, uFlags)

Divides the bitmap into segments where each segments pixels have approximately the same color (homogenous color).



Pointer to the bitmap handle referencing the bitmap to be changed.

L_UINT uThreshold

The tolerance value of each segment. Valid values for this parameter are:

L_UINT uFlags

Flag that indicates the color space used in the segmentation.  Possible values are:

Value Meaning
SGM_RGB [0x00001] Comparison done on red, green and blue difference.
SGM_Y [0x00002] Comparison done on Y channel difference of YUV space.
SGM_U [0x00003] Comparison done on U channel difference of YUV space.
SGM_V [0x00004] Comparison done on V channel difference of YUV space.
SGM_UV [0x00005] Comparison done on U and V channels difference of YUV space.
SGM_NGTV_UV [0x00010] Consider negative values of U and V of YUV color space. This flag is used only with the SGM_U or SGM_V flags.


Value Meaning
SUCCESS 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.

This function divides the images into segments according to its pixel values. The segment shapes will be arbitrary. Adjacent pixels with approximately the same values are put together into homogenous segments. The function may be performed on the RGB and YUV color spaces.  

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

This function supports 12 and 16-bit grayscale and 48 and 64-bit color images. Support for 12 and 16-bit grayscale and 48 and 64-bit color images is available in the Document and Medical Imaging toolkits.

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


Win32, x64, Linux.

See Also




This example loads a bitmap and segmentation function.

L_INT SegmentBitmapExample(L_VOID) 
   L_INT nRet; 
   BITMAPHANDLE LeadBitmap;   /* Bitmap handle to hold the loaded image. */ 
   /* Load the bitmap, keeping the bits per pixel of the file */ 
   nRet = L_LoadBitmap (MAKE_IMAGE_PATH(TEXT("PDFSegmentation.pdf")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL);  
   if(nRet !=SUCCESS) 
      return nRet; 
   /* segment the bitmap */ 
   nRet = L_SegmentBitmap (&LeadBitmap, 20,  SGM_RGB); 
   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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