function Y=mcut(I,level);
% Median Cut renk kuantalayici
% I, RGB renkli bir goruntu
% level, goruntuyu ifade etmek istediginiz renk sayisi
% Y, kuantalanmis uint8 goruntu
%
% Yazan  : Seyhan AGAOGLU   
% seyhan_eng@yahoo.com
% SAKARYA UNIVERISTESI

I = double(I);
R = I(:,:,1);
G = I(:,:,2);
B = I(:,:,3);

m = size(I,1);
n = size(I,2);
num = 1;

for i=1:m
    for j=1:n
        DR(num)=R(i,j);
        DG(num)=G(i,j);
        DB(num)=B(i,j);
        num = num + 1;
    end
end

for i=1:m*n
    indice(i)=i;
end

data = [DR; DG; DB; indice];
divider = size(indice,2);
step = log2(level);
for i=1:step
    [data,divider,color]=stepmcut(data,divider);
end

Data = sortrows(data',4);
data = Data';

x=1;
y=1;
for i=1:size(indice,2)
    f = data(5,i);
    Y(x,y,1) = color(f,1);
    Y(x,y,2) = color(f,2);
    Y(x,y,3) = color(f,3);
   
    y = y + 1;
   
    if y == n+1
        x = x + 1;
        y = 1;
    end
end

% end of function

function [sdata,sdivider,color]=stepmcut(Data,divider);
% Median Cut renk kuantalayici
%
% Yazan  : Seyhan AGAOGLU   
% seyhan_eng@yahoo.com
% SAKARYA UNIVERISTESI

data(1:4,:)=Data(1:4,:);

sub_number = size(divider,2);
a = 1;
start = 1;
old_start = 1;
to_end = divider(1);
old_end = divider(1);
new_data = data;

for indice=1:sub_number
    s_count = 0;
    for i=start:to_end
        Temp(:,s_count+1) = data(:,i);
        s_count = s_count + 1;
    end   
   
    maxR = max(Temp(1,:));
    minR = min(Temp(1,:));
    maxG = max(Temp(2,:));
    minG = min(Temp(2,:));
    maxB = max(Temp(3,:));
    minB = min(Temp(3,:));

    l(1) = maxR - minR;
    l(2) = maxG - minG;
    l(3) = maxB - minB;
    f = find (l(:)==max(l));

    S = sortrows(Temp',f);
    S = S';

    lenght = size(S,2);
    l1 = round(lenght/2);
    l2 = lenght - l1;
       
    new_divider(a)=l1;
    if l2~=0
        new_divider(a+1)=l2;
        a = a + 2;
    else
        a = a + 1;
    end
   
    i_count = 0;
    for i=start:to_end
        new_data(:,i) = S(:,i_count+1);
        i_count = i_count + 1;
    end
   
    if indice~=sub_number
        start = old_start + s_count;
        old_start = start;
        to_end = old_end + divider(indice+1);
        old_end = to_end;
    end
   
    Temp = [0;0;0;0];
end

sdivider = new_divider;
sdata = new_data;
new_data = double(new_data);

old_j = 0;
sum = double([0;0;0;0]);
for i=1:size(sdivider,2)
    c_count = sdivider(i);
    for j=1:c_count
        sum = sum + new_data(:,j+old_j);
        sdata(5,j+old_j) = i;
    end
    color(1:3,i) = sum(1:3,:)/c_count;
    old_j = old_j + c_count;
    sum = double([0;0;0;0]);
end

color = uint8(round(color))';

% end of function