thress.m

clc; 
clear all; 
close all; 

img = (imread('deer1.jpg')); 
T = input('Input Threshold'); 

T1 = uint32(0); 
T2 = uint32(0); 
T1n = 0; 
T2n = 0; 
T1mean = 0; 
T2mean = 0; 
Tdiff = 21;
[x y] = size(img); 
val = uint64(0);
while(~(Tdiff < 5 && Tdiff > -5))
    for i = 1:x
        for j = 1:y
            val = uint32(img(i,j)); 
            if val < T
                T1 = T1 + val;
                T1n = T1n + 1; 
            else
                T2 = T2 + val;
                T2n = T2n + 1;
            end
        end
    end
    T1mean = (T1/T1n);
    T2mean = (T2/T2n);
    Tnew  = (T1mean + T2mean)/2;
    Tdiff = abs(int32(Tnew) - int32(T));
    disp(sprintf('Tdiff = %d', Tdiff));
    if Tdiff > 5
        T = Tnew; 
        disp(sprintf('New value of T = %d', T));
    end
    T1 = 0;T1n = 0;T2 = 0;T2n = 0;
end
im2 = img; 
for i= 1:x
    for j= 1:y
        if(img(i,j) > T)
            im2(i,j) = 255;
        else
            im2(i,j) = 0;
        end
    end
end
[level EM]  = graythresh(img);
img2 = im2bw(img,level); 

subplot(3,1,1); 
imshow(img), title('Orignal image'); 
subplot(3,1,2); 
imshow(img2), title('Threshold image inbuilt function');
subplot(3,1,3);
imshow(im2),title('Thr');