3 x 3 mean and meadian replacement

Never used matlab so it is all new to me. I have to compute the mean and medain of the pixels by 3x3 neighborhoods around all the pixels. I did mean part, not sure if correct. And for the median I have no clue.

I = normrnd(128,8,[256,256]);
imshow(I,[0,255]); % Pick indices to repalce with black and white
Iv = reshape(l,[],1);
histogram(Iv);
---------------
[m,n] = size(I) ; 
X = randperm(m*n,round(m*n*10/100)) ; 
X1 = randsample(X,length(X)/2) ; 
X2 = setdiff(X,X1); 
I(X1) = 0 ; % black
I(X2) = 255 ; % white 
imshow(I,[0,255])
Xv = reshape(I,[],1);
histogram(Xv);                    (credit to @KSSV)
-----------------
output1 = 1/3*ones(3,1);
    H = output1*output1';                             This is my mean attempt, not too sure if correct
    imfilt = filter2(H,I);
    imshow(imfilt,[0,255]);
    histogram(imfilt);
------------------------------
p = medfilt2(outout1);              I have tried this for the median, but i keep getting a dimension 2 error
    imshow(p,[0,255]);

Answer 1

[Matt J]

medfilt2 is the correct thing to use. Perhaps the problem is the argument "outout1" which seems to be misspelled.

[Rafael Rivas]

Missed that but no the message I get is "Undefined function 'medfilt2' for input arguments of type 'double'."

[Matt J]

That likely means you do not have the Image Processing Toolbox installed.

[Rafael Rivas]

wow spent two hours just for something so simple. thank you.