test-mean-filter.m

%{  Filters
% near 2 | 4 | 6
% 
% mean 
% (4,4)   (4,5)   (4,6)
% (5,4)   (5,5)   (5,6)
% (6,4)   (6,5)   (6,6)
% 
% %}

function SI = meanFilter(I)
[R,C] = size(I);
SI = uint8(zeros(R,C));
for r=1:R
    for c=1:C
        total = 0.0;
        counter = 0;
        for i=-1:1
            for j=-1:1
                if(((r+i)>0) && ((c+j)>0) && ((r+i)<=R) && ((c+j)<=C))
                    total = total + double(I(r+i,c+j));
                    counter = counter + 1;
                end
            end
        end
        SI(r,c)= total/counter;
    end
end