clear;clc;
F = 3;
Nrows = 7;
Ncols = 7;
P = 0;
S = 2;
Orows = (Nrows+2*P+S-F)/S;
Ocols = (Ncols+2*P+S-F)/S;
%
input = ones(Nrows,Ncols);
filter = 1:1:(F*F);
filter = reshape(filter,F,F);
new_filter = zeros(size(input,1)+2*P,size(input,2));
new_filter(1:size(filter,1),1:size(filter,2))=filter;
new_filter_vector = new_filter(:); %reshape(new_filter,size(new_filter,1)*size(new_filter,2),1)
nfv_long = zeros((Nrows+2*P)*(Ncols+2*P),1);
nfv_long(1:size(new_filter_vector,1))=new_filter_vector;
new_filter_vector = nfv_long;
%
weight_matrix = zeros(Orows*Ocols,Nrows*Ncols);
new_filter_vector_shifted = new_filter_vector;

for i=1:Orows*Ocols   
    [i,j];
    for j=0:Nrows-1
        j*Ncols+1:j*Ncols+Ncols;
        new_filter_vector_shifted((Ncols+2*P)*(j+P)+P+1:(Ncols+2*P)*(j+P)+P+Ncols);
        weight_matrix(i,j*Ncols+1:j*Ncols+Ncols) = new_filter_vector_shifted((Ncols+2*P)*(j+P)+P+1:(Ncols+2*P)*(j+P)+P+Ncols);
    end 
    new_filter_vector_shifted = circshift(new_filter_vector_shifted,1);
    new_filter_vector_shifted(1)=0;
    if(~mod(i,Orows))
        new_filter_vector_shifted = circshift(new_filter_vector,(Ncols+2*P)*i/Orows);
        new_filter_vector_shifted(1:(Ncols+2*P)*i/Orows)=0;
    end
end