clear all;
close all;
clc

Image = imread('Lenna.png');
%Image = imread('k.jpg');
Gray = rgb2gray(Image);
GrayFFT = fft(Gray);
dim = length (GrayFFT);
sample = zeros(3);

mask = [ 0,-1, 0;
        -1, 4,-1;
         0,-1, 0];

%co tu powinno być?
Masked = Gray;

for row = 2:dim -1
    for col = 2:dim-1
    sample = GrayFFT((row-1):(row+1),(col-1):(col+1));
    sample = sample .* mask;
    Masked(row,col) = sum(sum(sample));
    end
end;

Out = ifft(Masked);

imwrite(real(Out),'Out.png');

imshow(real(Out), [real(min(Out(:))) real(max(Out(:)))] );

% Comparison = [Gray,Out];
% imwrite(Comparison,'Comparison.png');
% imshow(Comparison);