MATLAB: Convolution of a matrix

Question

I've tried to code some of the problem and it is working for a 3*3 filter

Answer 1

Check conv2() to avoid for loop. Following correct the mistake in your code

clc;
clear all;
close all;
im=double(imread('cameraman.tif'));
w=[1 1 1 1 1;1 1 1 1 1;1 1 1 1 1;1 1 1 1 1;1 1 1 1 1;];
k = floor(size(w,1)/2);
[M,N]=size(im);
g = zeros(M, N);
for i=k+1:M-k
    for j=k+1:N-k
        g(i,j)=sum(im(i-k:i+k,j-k:j+k).*w, 'all');
    end
end
figure,imshow(im,[]);
figure,imshow(g,[]);

A simple version with conv2

im=im2double(imread('cameraman.tif'));
w=ones(5);
g = conv2(im, w, 'same');
figure,imshow(im,[]);
figure,imshow(g,[]);