Discrete Fourier Transform-Based Steganography

Abstract

In this chapter, discrete Fourier transform (DFT)-based steganographic process has been discussed in details. The generalized DFT and IDFT equation pair is given from where sub-image-based (small nonoverlapping window) reversible computations using DFT and IDFT is done. Numerical examples are given for both 1D and 2D DFT and IDFT transform computation for confirmation of reversibility. LSB encoding on 8 x 4 sub-image is also given completely with flow diagram. A complete algorithm of DFT-based steganography is given with a capacity of embedding payload of 0.75bpB along with its implementation results and analysis.