%%%%%%%%%%%%%%%%%%%%%%%%%%%%Image Not Modified%%%%%%%%%%%%%%%%%%%%%
%encrypt blue and insert into red componant at bit no. 2 and detect originalty of image 
%at time domain 
clc
clear all
tic;
% hash processing by SHA160 to get photo ID from camera ID 
CameraID='acef'
L=length(CameraID)
METH='SHA160';
[digest, MSG_RAW_512] = hash(L,METH,0,CameraID);
k1=[digest];
%figure (1), imshow(double(K1));
k=k1(1:16);%photo ID
%figure (2), imshow(uint8(K));
%----------------------------------------------------------------------------------------------------------------
I=imread('gastro.jpg');
R=I(:,:,1);
G=I(:,:,2);
B=I(:,:,3);
figure(1),imshow(R)
figure(2),imshow(G)
figure(3),imshow(B)
figure(4),imshow(I)
%% %To resize Red(R) matrix and no reminder element
[r,c]=size(R);
if (rem(r,8)~=0)
   r=r+ (8-rem(r,8));
end
if (rem(c,8)~=0)
   c=c+ (8-rem(c,8));
end
NewimgR=zeros(r,c);
NewimgR(1:size(R,1),1:size(R,2))=R;
RM=NewimgR;
figure(5), imshow (uint8(NewimgR));
%% %To resize Green(G) matrix and no reminder element 8*8
[r,c]=size(G);
if (rem(r,8)~=0)
   r=r+ (8-rem(r,8));
end
if (rem(c,8)~=0)
   c=c+ (8-rem(c,8));
end
NewimgG=zeros(r,c);
NewimgG(1:size(G,1),1:size(G,2))=G;
GM=NewimgG;
figure(6), imshow (uint8(GM));
%To resize Blue(B) matrix for encryption processing by AES 4*4
[r,c]=size(B);
if (rem(r,8)~=0)
   r=r+ (8-rem(r,8));
end
if (rem(c,8)~=0)
   c=c+ (8-rem(c,8));
end
NewimgB=uint8(zeros(r,c));
NewimgB(1:size(B,1),1:size(B,2))=B;
BM=NewimgB;
figure(7), imshow (uint8(BM));
%----------------------------------------------------------------------------------------------------------------
%Encryption process by AES for blue componant
for i=1:4:r
    for j=1:4:c
        pb=NewimgB(i:i+3, j:j+3);
        plaintext= pb;
        ssi;
        %plaintext=['A' 'B' 'C' 'D' 'E' 'F' 'G' 'H' 'I' 'J' 'K' 'L' 'M' 'N' 'O' 'P'];
        plain=reshape(plaintext,4,4);
        plain = double(abs (plain));
        %key = ['0' '0' '6' '0' 'b' '9' '0' 'a' 'f' 'm' 'h' 'l' 'f' 'a' 'k' 'n'];%key = Photo ID
        key=k;%Photo ID
        key=abs(key);
        w = key_expansion (key, s_box, rcon);
        ciphertext = cipher (plain, w, s_box, poly_mat,ind_matleft);
%         ciphertext = reshape(ciphertext,1,16);
        cb(i:i+3, j:j+3)=ciphertext;
    end
end
ciphertext = char(cb);
Newimgcb=cb;
EBmidsb=bitget ((cb),2);%extraction bit no. 2 of encrypted blue
figure (8),imshow(uint8(cb));
%figure (9),imshow(uint8(db));
RMmidsb=bitget ((RM),2);%extraction bit no. 2 of  red coponanet 
NRM=bitset(RM,2,EBmidsb);%modified red componanet which substituted by bit no. 2 of encrypted blue
db=dec2bin (EBmidsb);
dRM=dec2bin(RM);
dNRM=dec2bin(NRM);
figure (9),imshow(uint8(EBmidsb));
%bm=dec2mvl(BM);%bb=dec2bin(BM);%bb1=bitget((BM),1);%bg=dec2bin(GM);%bg1=bitget((GM),1);
%bm2=bitget((BM), 8);%bf=bitset(BM,2,GM);%bf1=dec2bin(bf);
figure(10),imshow(uint8(NRM));%red modified
%to get resized original image without prints
[rR,cR]=size(NewimgR);
NI(:,:,1)=(NewimgR(1:rR,1:cR));
[rG,cG]=size(GM);
NI(:,:,2)=(GM(1:rG,1:cG));
[rB,cB]=size(BM);
NI(:,:,3)=(BM(1:rB,1:cB));
figure(11),imshow(uint8(NI))
%To get image with prints
[rR,cR]=size(NRM);
NewI(:,:,1)=(NRM(1:rR,1:cR));
[rG,cG]=size(GM);
NewI(:,:,2)=(GM(1:rG,1:cG));
[rB,cB]=size(BM);
NewI(:,:,3)=(BM(1:rB,1:cB));
figure(12),imshow(uint8(NewI));
Y=sum(abs(sum(NRM-NewimgR)))/(r*c);%mean absolute error between red with prints and original resized red
figure (13),imshow(uint8(Y));
Y1=sum(abs(sum(NewI-NI)))/(3*r*c);%mean absolute error between image with prints and original resized red
figure (14),imshow(uint8(Y1));
toc;
%Metrics block for performance measurement
MAE = mae(uint8(NewI),uint8(NI));%the mean of absolute errors 
fprintf('\n The mean-absolute error is %0.4f\n', MAE);
MSE = immse (uint8(NewI), uint8(NI));%mean square error between Stego-image and cover(original) image
fprintf('\n The mean-squared error is %0.4f\n', MSE);
PSNR= psnr(uint8(NewI), uint8(NI));% peak signal to noise Ratio for the image with prints, with the original image as the reference 
[PSNR, snr] = psnr(uint8(NewI), uint8(NI));
fprintf('\n The Peak-SNR value is %0.4f', PSNR);
fprintf('\n The SNR value is %0.4f \n', snr);
ssimval = ssim(uint8(NewI), uint8(NI));%computes the Structural Similarity Index (SSIM) value for NewI image(image with print) using NI(original image) as the reference image
fprintf('The SSIM value is %0.4f.\n',ssimval);
corr=corr2(uint8(NRM),uint8(NewimgR));%loss of correlation between image with print signs and original image.
fprintf('\n The loss of correlation is %0.4f\n', corr);
m1=mean2 (uint8(NewI));%Mean or avarage for image with prnt signs
m2=mean2 (uint8(NI));%Mean or avarage for original image 
LD=2*(m1.*m2)./((m1.^2)+(m2.^2));%luminance distortion
fprintf('\n The luminance distortion is %0.4f\n', LD);
s1=std2 (uint8(NewI));%standard division for image with prnt signs 
s2=std2 (uint8(NI));%standard division for image with prnt signs 
CD=2*((s1.*s2)./((s1.^2)+(s2.^2)));%contrast distortion
fprintf('\n The contrast distortion is %0.4f\n', CD);
Q=corr*LD*CD% Universal Image Quality Index (UIQI):
fprintf('\n The Universal Image Quality Index (UIQI) is %0.4f\n', Q);
%++++++++++++++++++++++++++++++++**************************************===========================================
%++++++++++++++++++++++++++++++++**************************************===========================================
%++++++++++++++++++++++++++++++++**************************************===========================================
%reverse algorithm to detect any manuipolation
I1=NewI;
R1=NewI(:,:,1);
G1=NewI(:,:,2);
B1=NewI(:,:,3);
figure(15),imshow(uint8(R1))
figure(16),imshow(uint8(G1))
figure(17),imshow(uint8(B1))
figure(18),imshow(uint8(I1))
NewimgB1=B1;
%---------------------------------------------------------------------------------------------------------------
%Encrytion processing for blue componant 
for i=1:4:r
    for j=1:4:c
        pb=NewimgB1(i:i+3, j:j+3);
        plaintext= pb;
        ssi;
        %plaintext=['A' 'B' 'C' 'D' 'E' 'F' 'G' 'H' 'I' 'J' 'K' 'L' 'M' 'N' 'O' 'P'];
        plain=reshape(plaintext,4,4);
        plain = double(abs (plain));
        %key = ['0' '0' '6' '0' 'b' '9' '0' 'a' 'f' 'm' 'h' 'l' 'f' 'a' 'k' 'n'];%key = photo ID
        key=k;%Photo ID
        key=abs(key);
        w = key_expansion (key, s_box, rcon);
        ciphertext = cipher (plain, w, s_box, poly_mat,ind_matleft);
%         ciphertext = reshape(ciphertext,1,16);
        cb1(i:i+3, j:j+3)=ciphertext;
    end
end
ciphertext = char(cb1);
Newimgcb1=cb1;
figure (19),imshow(uint8(cb1));
% to extract bit no. 2 from encrypted matrix which compared with red modified
EBmidsb1=bitget((cb1),2);
NRM1=bitget((R1),2);
db1=dec2bin (EBmidsb1);
dNRM1=dec2bin(NRM1);
figure(20),imshow(uint8(EBmidsb1));
figure(21),imshow(uint8(NRM1));
X1=sum(sum(abs(NRM1-EBmidsb1)));%varation between original image and manuipolated image
X=corr2 (uint8(NRM1), uint8(EBmidsb1));% correlation between Extracted print signs and Calculated print signs
if X==1
        disp('<<<<<<<<<<<<<<Original>>>>>>>>>>>>>>>');
else
        disp('<<<<<<<<<<<<<<<<<NOt Original>>>>>>>>>>>>>');
end
figure (22),imshow (uint8(X));
toc;