






The Median filter smoothes images using a fast median algorithm.
The median algorithm is particularly good at removing "salt and
pepper" noise from images without removing too much fine
detail.














Name


Default


Description










Width 

3 pixels 

The width of the median filter to be applied. 









Height 

3 pixels 

The height of the median filter to be applied. 









X 

2 pixels 

The horizontal center of the filter in pixels from top
left. 









Y 

2 pixels 

The vertical center of the filter in pixels from top left. 


















The median filter replaces each pixel with the median of its
neighbors. The Median has a number of advantages over the Mean.
Firstly unrepresentative pixels do not unduly influence the outcome
of the final pixel level  this is why the filter is good at
removing "salt and pepper" noise. Secondly, because the final pixel
must actually be the value of one of its neighbors, edges are
preserved more faithfully.
The image below show the neighboring pixels polled in a 4 by 3
Median Filter.








The following example images show the effect of a Median filter
applied to a noisy picture at different width and height
settings.



Original Image before Median Filter



Width = 3, Height = 3, X = 2, Y = 2



Width = 5, Height = 5, X = 3, Y = 3



Width = 9, Height = 9, X = 4, Y = 4



