A unified audio and image steganography by spectrum modification

A method of embedding information in the spectral domain of a cover audio and a cover image that can be extended to video frames is proposed. The technique exploits the imperceptibility of human auditory and visual systems at low levels of spectral changes. By selectively altering the spectrum at a pair of one-dimensional frequencies by a small percentage of the average power of a segment of audio or image, the psychoacoustical or psychovisual masking property enables unnoticeable embedding with a large payload. Initial studies on the effect of Gaussian noise added to the stego demonstrate the robustness of the technique to noise in both the stego audio and image. The imperceptibility of the technique combined with high payload, robustness of embedded data and accurate data retrieval renders the proposed steganography suitable for covert communication and secure data transmission applications.