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L_GaussianFilterBitmap

Summary

Smooths or blurs an image by applying a Gaussian filter to the specified bitmap.

Syntax

#include "l_bitmap.h"

L_LTIMGEFX_API L_INT L_GaussianFilterBitmap(pBitmap, nRadius, uFlags)

Parameters

pBITMAPHANDLE pBitmap

Pointer to a bitmap handle that references the bitmap to process with the Gaussian filter.

L_INT nRadius

Value that indicates the radius of the neighborhood on which the filter is applied.

Returns

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

Comments

Each pixel in the bitmap is blurred based on neighborhood pixels. The parameter nRadius determines the size of the neighborhood to consider when blurring a pixel. The result is a blurred version of the original image.

The amount of blur is controlled by specifying the size of the neighborhood used for blurring or smoothing. The value of the nRadius parameter determines the size and values of the mask.

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.

Gaussian Filter Function - Before

Gaussian Filter Function - After

View additional platform support for this Gaussian Filter function.

Required DLLs and Libraries

LTIMGEFX
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, Linux.

Example

This example loads a bitmap and applies the Gaussian filter

L_INT GaussianFilterBitmapExample(L_VOID) 
{ 
   L_INT nRet; 
   BITMAPHANDLE LeadBitmap; 
   nRet = L_LoadBitmap(MAKE_IMAGE_PATH(TEXT("IMAGE1.CMP")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if (nRet != SUCCESS) 
      return nRet; 
 
   nRet = L_GaussianFilterBitmap(&LeadBitmap, 20, 0); 
   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; 
}