i have this code to embed. How can i extract the secret message from the stego JPEG? also there is bright in the image when i apply the dct2 does anyone know how to solve it. here is my embedding process code :

3 vues (au cours des 30 derniers jours)
Zamzam
Zamzam le 28 Août 2014
Modifié(e) : Zamzam le 30 Août 2014
clear; clc;
a= imread ('lena.jpg'); I1=rgb2gray(a);
f = double(I1);
f= f-128; [mf, nf]= size(f); mb=mf/8; nb=nf/8;
% the input image
Ff = blkproc(f, [8 8],'dct2');
% customized Q table quanttable=1*[16 11 10 16 24 40 51 61; 12 12 14 19 26 58 60 55; 14 13 16 24 40 57 69 56; 14 17 22 29 51 87 80 62; 18 22 37 56 68 109 103 77; 24 35 55 64 81 104 113 92; 49 64 78 87 103 121 120 101; 72 92 95 98 112 100 103 99];
Fq= round (blkproc(Ff,[8 8], @(x)x./quanttable));
imwrite(Fq, 'Compressed.jpg'); RFf= round(blkproc (Ff,[8 8], @(x)x./quanttable)); invdct= @idct2; x= blkproc(RFf,[8 8],invdct);
Imwrite(x, 'cover.jpg');
Cover=imread('cover.jpg');
b=input('your words ? ');
c=double(b);
d=dec2bin(c);
[q w]=size(d);
siz=q*w;
%% first pixel
for i=1:siz, x=dec2bin(Cover(i)); x(8)=d(i); y=bin2dec(x); Cover(i)=y; end
Cover(256,256)=q;
%%
for i=1:siz, X=dec2bin(Cover(i)); D(i)=X(8); end
data=char(bin2dec(reshape(D,q,w))); data=data';
msgbox(data);
imwrite(Cover,'stego.jpg') Stegoimage=imread ('stego.jpg');
%%
subplot(211);imshow(Cover); subplot(212);imshow(Stegoimage);

Connectez-vous pour répondre à cette question.

Réponses (0)

Catégories

En savoir plus sur Image Transforms dans Help Center et File Exchange

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by