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L_RemoveSaltPepperNoise

Summary

Removes the salt and pepper noise from the specified bitmap.

Syntax

#include "l_bitmap.h"

L_LTIMGCOR_API L_INT L_RemoveSaltPepperNoise(pBitmap)

Parameters

pBITMAPHANDLE pBitmap

Pointer to the bitmap handle that references the bitmap on which to apply the effect.

Returns

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

Comments

This function works only on 8-bit images. It removes salt (pixels having a value of 255) and pepper (pixels having a value of 0) and replaces them with the median value of the non-noisy pixels around them.

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.

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

Salt and Pepper Removal Function - Before

Salt and Pepper Removal Function - After

View additional platform support for this Salt and Pepper Removal 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.

Example

This example loads a bitmap and removes the salt and pepper noise from it (check the before and after images, and focus on the area in the middle).

L_INT L_RemoveSaltPepperNoiseExample(L_VOID) 
{ 
   L_INT nRet; 
   BITMAPHANDLE LeadBitmap;   /* Bitmap handle for the image */ 
 
   /* Load a bitmap at its own bits per pixel  */ 
   nRet = L_LoadBitmap(MAKE_IMAGE_PATH(TEXT("cannon_noisy.png")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if (nRet != SUCCESS) 
      return nRet; 
 
   /* Apply the function to the image*/ 
   nRet = L_RemoveSaltPepperNoise(&LeadBitmap); 
   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 the bitmap  
   if (LeadBitmap.Flags.Allocated) 
      L_FreeBitmap(&LeadBitmap); 
 
   return SUCCESS; 
}