clc;
clear ;
tic;
input_image=imread('test3.bmp');
input_image = rgb2gray(input_image);
%input_image = double(input_image);
a=uint8(2);
beta=uint8(2);
sum1=0;
cnt = uint8(0);
difference = uint64(0);
histogram_of_image = zeros(1,256); %creata an array for histogram
[width,height] = size(input_image); %width and heigth of image

figure;
plot(imhist(input_image));
title('Original Histogram');
histogram_of_image = imhist(input_image);

modified_histogram = zeros(1,256);

for i=1:256
  modified_histogram(i)  = (log( histogram_of_image(i)+double(a)))^double(beta);
end

figure('Name','Modified Histogram');
plot(modified_histogram);


for i=1:256
    if(modified_histogram(i)~=0)
        sum1 = sum1 + (modified_histogram(i));
        cnt = cnt + 1;
    end
end

tcl = sum1/cnt;

clipped_histogram = zeros(1,256);
for i=1:256
    if((modified_histogram(i)) >= tcl)
    clipped_histogram(i) = tcl;
    else
    clipped_histogram(i) = (modified_histogram(i));
   end
end

   figure('Name','Clipped Modified Histogram');
   plot(clipped_histogram);

PDa = zeros(1,256);
for i=1:256
 PDa(i) = clipped_histogram(i) / (sum(clipped_histogram));
end

CDa = zeros(1,256);  %create CDa in formula
CDa(1) = PDa(1) ;
for i=2:256
     CDa(i) =  PDa(i) +  CDa(i-1);
end


value_after_enhancement =  zeros(1,256);
for i=1:256
     value_after_enhancement(i) = (255 * CDa(i));
end


b=uint8(0);
output_image=zeros(width,height);
for i=1:width %map new value
    for j=1:height
            b = input_image(i,j);
            output_image(i,j) =   value_after_enhancement(b);
    end
end


original_result=imread('testsonuc3.bmp');
original_result=double(rgb2gray(original_result));
image_of_dif= zeros(width,height);
for i=1:width %map new value
    for j=1:height
        d = (output_image(i,j));
        e = (original_result(i,j));
        difference = difference + uint64(abs(d-e));
       piksel_farki=e-d;
        %i has casted to uint64, because type of difference is also uint64
        image_of_dif(i,j)= abs(d-e);

    end
end

figure;
imshow(uint8(output_image));
title('My Result');


figure;
imshow(uint8(original_result));
title('Original Result');

figure;
imshow(uint8(image_of_dif));
title('Difference of original result and my result');
toc;