medianBlur smoothes an image using a median filter, i.e.
the value of each pixel is replaced by the median value of all the pixels in
its neighborhood.
The half-size in pixels of the kernel (default: 5).
in_place
A logical indicating whether the change should be applied to
the image itself (TRUE, faster but destructive) or to a copy of it (FALSE,
the default, slower but non destructive).
Value
An Image object if in_place=FALSE. Otherwise, it
returns nothing and modifies image in place.