HP110v3_Decoder.m

bcode = imread('HP110v3.png');%Barcode Image %loading
xn = bcode(250, :);% row 250 was chosen randomly to %process the barcode
difh = [1 -1];% difference filter
yn = conv (double(xn),double(difh));% Filtered xn
subplot(211), stem(xn)
subplot(212), stem(yn)
%The following for loop creates a threshold signal with %zeros and ones where one represents an edge.
for m =1:949
      if (abs(yn(1,m)) < 50) % Threshold value: =50
         dn(1,m) = 0;
      else
         dn(1,m) = 1;
      end
end
ln = find (dn);
stem (ln)
delta_n = conv(ln,difh);
subplot(211), stem (ln)
subplot(212), stem(delta_n)
% most of the values of the deltan are 8,16,24,32
sum = 0;
for n = 7:65
       sum = sum + delta_n(1,n);
end
divider = sum / 95; % divider = 7.8947368421052
for n = 1:71
      delta_n(1,n) = delta_n(1,n)/divider;
end
for n=1:71
    if (delta_n(1,n) >0.5 && delta_n(1, n) <= 1.5)
            delta_n(1,n) = 1;
    end
    if (delta_n(1,n) >1.5 && delta_n(1, n) <= 2.5)
           	delta_n(1,n) = 2;
    end
    if (delta_n(1,n) >2.5 && delta_n(1, n) <= 3.5)
           	delta_n(1,n) = 3;
    end
    if (delta_n(1,n) >3.5 && delta_n(1, n) <= 4.5)
           	delta_n(1,n) = 4;
    end
end
barcodearray = delta_n(1,7:65);
decodeUPC (barcodearray);