MATLAB: Manual median filter design

Question

Hello, I want to implement a simple median filter of window size '5' manually.I found a thread here

medain with blockpro(),nlfilter but when I tried with the help blockpro() and nlfilter() both showed nlfilter() and blockpro() not found. I don't have imageprocessing toolbox.

So,can anyone help me out in implementing the median filter manually.

Answer 1

Well if you don't have the Image Processing Toolbox, I'm afraid you won't be able to use blockproc. In that case, you would have to resort to something like this:

imout = zeros(size(im),class(im));
for m = 3 : size(im,1)-2
    for n = 3 : size(im,2)-2
        list = im(m-2:m+2,n-2:n+2);
        imout(m,n) = median(list(:));
    end
end

Note that this is the most naive way to do it. There are lots of better ways to do it, but this is the easiest to understand.