change border type for medianBlur to BORDER_ISOLATED

modules/imgproc/src/smooth.cpp

@@ -3162,7 +3162,7 @@ void cv::medianBlur( InputArray _src0, OutputArray _dst, int ksize )
     }
     else
     {
-        cv::copyMakeBorder( src0, src, 0, 0, ksize/2, ksize/2, BORDER_REPLICATE );
+        cv::copyMakeBorder( src0, src, 0, 0, ksize/2, ksize/2, BORDER_REPLICATE|BORDER_ISOLATED);
 
         int cn = src0.channels();
         CV_Assert( src.depth() == CV_8U && (cn == 1 || cn == 3 || cn == 4) );