Changes the color of each pixel in the class objects bitmap to the median color of pixels in its neighborhood. This is similar to the LBitmap::AverageFilter function, but it is used for noise reduction, rather than a blur effect.


#include "ltwrappr.h"

virtual L_INT LBitmap::MedianFilter(uDim=3, uFlags = 0)



Dimensions of the neighborhood used for filtering (uDim x uDim), in pixels.

L_UINT32 uFlags

Reserved for future use. Must be 0.


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


You control the effect by specifying the size of the neighborhood that is used for calculating the median value. For 8x8, pass 8 in the uDim parameter.

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

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 only in the Document/Medical toolkits.

If the class objects bitmap has a region, this function works only on the region. If the bitmap does not have a region, the function works on the entire bitmap.

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.

Median Function - Before

Median Function - Before

Median Function - After

Median Function - After

View additional platform support for this Median function.

Required DLLs and Libraries


Win32, x64.

See Also




L_INT LBitmap__MedianFilterExample() 
   L_INT nRet; 
   LBitmap LeadBitmap; 
   nRet =LeadBitmap.Load(MAKE_IMAGE_PATH(TEXT("ImageProcessingDemo\\NaturalFruits.jpg")), 0,ORDER_BGR); 
   if(nRet !=SUCCESS) 
      return nRet; 
   nRet =LeadBitmap.MedianFilter(); 
   if(nRet !=SUCCESS) 
      return nRet; 
   return SUCCESS; 
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