How to apply a filter to an image?

So this is some hints that my professor gave us on our project, and I am stuck on the part where you are suppossed to apply the filter using imfilter.In part C there is the filter we used, that I made into an array, and I don't know how to apply said filter.

Answer 1

[Spectro]

First you need to declare and read your picture:

img = imread('your_picture.bmp');

If you have already created matrices according to the assignment C - i. And ii. and that would be something like this:

I = [1/9 1/9 1/9;1/9 1/9 1/9;1/9 1/9 1/9];
II = [-1 -1 0;-1 0 1;0 1 1];

Finally, you want to use an imfilter() to filter image separately with created filters (matrices):

filtered_img1 = imfilter(img, I);
filtered_img2 = imfilter(img, II);

And if you want to show filtered images both at the same time:

subplot(121)
imshow(filtered_img1)
subplot(122)
imshow(filtered_img2)