#include "l_bitmap.h"

L_LTIMGCOR_API L_INT L_RemoveSaltPepperNoise(pBitmap)


pointer to the bitmap handle

Removes the salt and pepper noise from the specified bitmap.

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


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


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.

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.

See Also

Functions: L_DespeckleBitmap, L_MedianFilterBitmap, L_BinaryFilterBitmap, L_MaxFilterBitmap, L_MinFilterBitmap, L_DlgAddNoise, L_AddBitmapNoise, L_AgingBitmap, L_MaskConvolutionBitmap, L_MaxFilterBitmap, L_MinFilterBitmap, L_AverageFilterBitmap, L_AddBitmaps, L_AddWeightedBitmaps, L_AnisotropicDiffusionBitmap, L_HighPassFilterBitmap, L_GaussianFilterBitmap, L_SRADAnisotropicDiffusion, L_TADAnisotropicDiffusion, L_AutoPageSplitter, L_DeinterlaceBitmap, L_SignalToNoiseRatio, L_PerspectiveDeskew, L_SmoothEdgesBitmap, L_BlurDetection, L_ExpandPage, L_GlareDetection, L_MICRDetection, L_MRZDetection, L_DynamicBinaryBitmap, L_MeanShiftFilterBitmap, L_TissueEqualizeBitmap, L_SigmaFilterBitmap, L_AnisotropicDiffusionBitmap
Topics: Raster Image Functions: Filtering Images
Removing Noise


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) 
	return SUCCESS; 

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