--- a
+++ b/Code/ostu.m
@@ -0,0 +1,43 @@
+function ostu_img=ostu(B);
+
+%Image contains 2 classes of pixels, foreground and background pixels.
+%Calculate optimal threshold such that inter-class variance is maximum
+B = imresize(B, [256, 256]);
+[r,c] = size(B);
+  
+ % Calculation of the normalized histogram
+    n = 256;
+    h = hist(B(:), n);        
+    h = h/(length(B(:))+1);
+    
+    % Calculation of the cumulated histogram and the mean values
+    cumSum = cumsum(h);
+    mu = zeros(n, 1); 
+    mu(1) = h(1);
+    for i=2:n
+        mu(i) = mu(i-1) + i*h(i);
+    end    
+         
+    % Initialisation of the values used for the threshold calculation
+    w0 = cumSum(1);
+    w1 = 1-w0;
+    mu0 = mu(1)/w0;
+    mu1 = (mu(end)-mu(1))/w1;
+    max = w0*w1*(mu1-mu0)*(mu1-mu0);
+    lev = 1;
+    
+    for i = 2:n
+        w0 = cumSum(i);
+        w1 = 1-w0;
+        mu0 = mu(i)/w0;
+        mu1 = (mu(end)-mu(i))/w1;
+        s = w0*w1*(mu1-mu0)*(mu1-mu0);
+        if (s > max)
+            max = s;
+            lev = i;
+        end
+    end
+    
+    % Normalisation of the threshold        
+    lev = lev/n;
+    ostu_img = imbinarize(uint8(B),lev);