Apply Average Filter on Image with just next-before 5 columns

I need to apply average filter but i should take just the average of next and before 5 columns and insert to center one.

I tried this but it doesn't look like worked:

a = imread("bridge.bmp");

j = mat2gray(a,[0 255]);

h = fspecial("average",[5 1]);

filtered = imfilter(j,h);

imshow(filtered);

Answer 1

[DGM]

Consider the example:

% a simple test image with a single white pixel in the center
inpict = zeros(13);
inpict(7,7) = 1;

% generate kernel such that target pixel is centered
fk = [1 1 1 1 1 1 1 0 0 0 0];
%               ^ this is the target pixel
fk = fk/sum(fk(:)); % sum-normalize

% apply filter
outpict = imfilter(inpict,fk,'replicate');

imshow(outpict)