Applying Median Filter

void medianBlur(InputArray src, OutputArray dst, int ksize)

Parameters:

• src – input 1-, 3-, or 4-channel image; when ksize is 3 or 5, the image depth should be CV_8U, CV_16U, or CV_32F, for larger aperture sizes, it can only be CV_8U.
• dst – destination array of the same size and type as src.
• ksize – aperture linear size; it must be odd and greater than 1, for example: 3, 5, 7 ...

You can find a nice example in OpenCV Documentation. 

 Example:

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#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"

using namespace std;
using namespace cv;

int main( int argc, char** argv )
 {

     Mat src = imread( "salt.tif", 1 );
     Mat dst;

     //Apply median filter
     medianBlur ( src, dst, 15 );
     imshow("source", src);
     imshow("result", dst);  

     waitKey(0);
     return 0;
 }

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