correlation analysis of two adjacent pixels

I had an color image and an encrypted version of the same. I need to find the horizontal vertical and diagonal correlation coefficient of each channels R G and B of both plain image and cipher image. Help me with code for the same.

[omar A.alghafoor]

are there any solution ?

if yes , I want this code .

Answer 1

[KSSV]

Read about corr2.

https://in.mathworks.com/help/images/ref/corr2.html

[omar A.alghafoor]

I have this code

% Finding correlation analysis of an image

% ----------------------------------------------

function corr(a,b)

a=imresize(a,[512,512]);

% Decompose in to R,G,B

%---------------------------------------

R=a(:,:,1);

G=a(:,:,2);

B=a(:,:,3);

%---------------------------------------

% Finding the correlation of adjacent pixels-------------Red

%----------------------------------------

A=double(R);

% Horizontal

x1 = A(:,1:end-1);

y1 = A(:,2:end);

fprintf(sprintf('%s Red:',b));

horizontal_values=corrcoef(x1,y1);

pause(1);

% Vertical

x2 = A(1:end-1,:);

y2 = A(2:end,:);

fprintf(sprintf('%s Red:',b));

vertical_vlaues=corrcoef(x2,y2)

pause(1);

% Diagonal,

x3 = A(1:end-1,1:end-1);

y3 = A(2:end,2:end);

fprintf(sprintf('%s Red:',b));

Diagonal_values=corrcoef(x3,y3)

%----------------------------------------

pause(4);

%----------------------------------------

% Correlation Figures

figure;

% plot(1,1),cor_figure(x1,y1,1),title(sprintf('%s Horizontal Red',b));

% plot(1,1),cor_figure(x2,y2,1),title(sprintf('%s Vertical Red',b));

% plot(1,1),cor_figure(x3,y3,1),title(sprintf('%s Diagonal Red',b));

subplot(131)

plot(x1,y1,'r'), title(sprintf('%s Horizontal Red',b));

subplot(132)

plot(x2,y2,'r'),title(sprintf('%s Vertical Red',b));

subplot(133)

plot(x3,y3,'r'),title(sprintf('%s Diagonal Red',b));

%----------------------------------------

pause(2);

%---------------------------------------

% Finding the correlation of adjacent pixels-------------Green

%----------------------------------------

A=double(G);

% Horizontal

x1 = A(:,1:end-1);

y1 = A(:,2:end);

fprintf(sprintf('%s Green:',b));

horizontal_values=corrcoef(x1,y1)

pause(1);

% Vertical

x2 = A(1:end-1,:);

y2 = A(2:end,:);

fprintf(sprintf('%s Green:',b));

vertical_vlaues=corrcoef(x2,y2)

pause(1);

% Diagonal,

x3 = A(1:end-1,1:end-1);

y3 = A(2:end,2:end);

fprintf(sprintf('%s Green:',b));

Diagonal_values=corrcoef(x3,y3)

%----------------------------------------

pause(1);

%----------------------------------------

% Correlation Figures

figure;

% plot(1,1),cor_figure(x1,y1,2),title(sprintf('%s Horizontal Green',b));

% plot(1,1),cor_figure(x2,y2,2),title(sprintf('%s Vertical Green',b));

% plot(1,1),cor_figure(x3,y3,2),title(sprintf('%s Diagonal Green',b));

subplot(131)

plot(x1,y1,'g'),title(sprintf('%s Horizontal Green',b));

subplot(132)

plot(x2,y2,'g'),title(sprintf('%s Vertical Green',b));

subplot(133)

plot(x3,y3,'g'),title(sprintf('%s Diagonal Green',b));

%----------------------------------------

pause(2);

%---------------------------------------

% Finding the correlation of adjacent pixels-------------Blue

%----------------------------------------

A=double(B);

% Horizontal

x1 = A(:,1:end-1);

y1 = A(:,2:end);

fprintf(sprintf('%s Blue:',b));

horizontal_values=corrcoef(x1,y1)

pause(1);

% Vertical

x2 = A(1:end-1,:);

y2 = A(2:end,:);

fprintf(sprintf('%s Blue:',b));

vertical_vlaues=corrcoef(x2,y2)

pause(1);

% Diagonal,

x3 = A(1:end-1,1:end-1);

y3 = A(2:end,2:end);

fprintf(sprintf('%s Blue:',b));

Diagonal_values=corrcoef(x3,y3)

%----------------------------------------

pause(1);

%----------------------------------------

% Correlation Figures

figure;

% plot(1,1),cor_figure(x1,y1,3),title(sprintf('%s Horizontal Blue',b));

% plot(1,1),cor_figure(x2,y2,3),title(sprintf('%s Vertical Blue',b));

% plot(1,1),cor_figure(x3,y3,3),title(sprintf('%s Diagonal Blue',b));

subplot(131)

plot(x1,y1,'b'),title(sprintf('%s Horizontal Blue',b));

subplot(132)

plot(x2,y2,'b'),title(sprintf('%s Vertical Blue',b));

subplot(133)

plot(x3,y3,'b'),title(sprintf('%s Diagonal Blue',b));

%----------------------------------------

end

%----------------------------------------

but plot for image encryption not accept

Answer 2

[Hyderkkk]

IA=rgb2gray(im2double(A));

c_diag = corrcoef(IA(1:end-1, 1:end-1), IA(2:end, 2:end));

c_vert = corrcoef(IA(1:end-1, :), IA(2:end, :));

c_horz = corrcoef(IA(:, 1:end-1, :), IA(:, 2:end));

figure;

subplot(3,3,1)

plot(IA(1:end-1, 1:end-1), IA(2:end, 2:end),'b'),title(sprintf('%s Horizontal Orginal image',b));

subplot(3,3,2)

plot(IA(1:end-1, :), IA(2:end, :),'b'),title(sprintf('%s Vertical Orginal image',b));

subplot(3,3,3)

plot(IA(:, 1:end-1, :), IA(:, 2:end),'b'),title(sprintf('%s Diagonal Orginal image',b));

IAA=rgb2gray(im2double(im12));

c_diage = corrcoef(IAA(1:end-1, 1:end-1), IAA(2:end, 2:end))

c_verte = corrcoef(IAA(1:end-1, :), IAA(2:end, :))

c_horze = corrcoef(IAA(:, 1:end-1, :), IAA(:, 2:end))

subplot(3,3,4)

plot(IAA(1:end-1, 1:end-1), IAA(2:end, 2:end),'r'),title(sprintf('%s Horizontal chiphered image ',b));

subplot(3,3,5)

plot(IAA(1:end-1, :), IA(2:end, :),'r'),title(sprintf('%s Vertical chiphered image',b));

subplot(3,3,6)

plot(IAA(:, 1:end-1, :), IA(:, 2:end),'r'),title(sprintf('%s Diagonal chiphered image',b));