Image steganography based on DWT integer coefficients

Question

I am trying to code DWT based steganography to hide an image inside another image. I am getting coefficients of subbands as float. How can I make them integers so that I can use lsb embedding?

Answer 1

This is also known as Integer Wavelet Transform. In Matlab this is achieved using lifting schemes. Define a lifting scheme with liftwave and use lwt2 and ilwt2 for the transformations.

lshaar = liftwave('haar','int2int');

[cA cH cV cD] = lwt2(x,lshaar);            % x is your data
ilwt2(cA,cH,cV,cD,lshaar);