How can i extract the hidden message from 1st, 2nd and 3rd bit plane of cover image and store in another text file?

fp = fopen('C:\Users\hello\Documents\MATLAB\Full RSA Implement\plaintext.txt','r+'); 
SecretMsg=fread(fp,256*256*3/8);
fclose(fp);
SM=de2bi(SecretMsg);
SM1=reshape(SM,256*3,length(SM)*8/(256*3));
HS = logical(SM1);
I1 = HS(1:256,1:256);
I2 = HS(257:512,1:256);
I3 = HS(513:768,1:256);
II = logical(I8)*128+logical(I7)*64+logical(I6)*32+logical(I5)*16+logical(I4)*8+logical(I3)*4+logical(I2)*2+logical(I1);

Here i have done to hide a file inside the bit plane of cover image. Then i don't know hoe to retrieve same hidden file in another text file.

[Geoff Hayes]

Sanjeeb - where have you defined I4 through I8? To decode, wouldn't you just reverse the assignment for II?

[Sanjeeb Behera]

I can't understand. Can you explain me please

Sanjeeb

Answer 1

[Image Analyst]

See attached demo.