close all
clear all
clc

I=imread('concordorthophoto.png');
[row col band]=size(I);

%% Vector
tic
I1=I(:);
m=row*col;  % m=length(I1);
box1=zeros(1,256);
for i=1:m
    con=I1(i)+1;
    box1(1,con)=box1(1,con)+1  ;
end
time_method1=toc;
name1='time for method 1 is= ';
name2=num2str(time_method1);
name3=' --> Vector';
name4=cat(2,name1,name2,name3);

%% matrix
tic
[row col band]=size(I);
box2=zeros(1,256);
for i=1:row
    for j=1:col
        con=I(i,j)+1;
        box2(1,con)=box2(1,con)+1  ;
    end
end
time_method2=toc;
name5='time for method 2 is= ';
name6=num2str(time_method2);
name7=' --> Matrix';
name8=cat(2,name5,name6,name7);

%% show
figure('name','Histogram');
subplot(2,2,1),imshow(I);title('Orginal Image')
subplot(2,2,2);plot(box1,'g');title(name8)
subplot(2,2,3),imhist(I);title('Matlab Histogram')
subplot(2,2,4);plot(box2,'r');title(name4)