Floating Signal Constellations for Multimedia Steganography

Conventional spread spectrum communication methods essentially map a discrete symbol from an alphabet to a length-N real valued sequence, which represents a point in the N-dimensional signal constellation. The real valued sequence is in turn transmitted over a communications channel. However, communication schemes for the purpose of multimedia steganography (or data hiding) have to transmit the real valued sequence corresponding to a point in the signal constellation superimposed on the original or cover content (without affecting the fldelity of the original content noticeably). The detector therefore, has to estimate the origin of the signal constellation, and thereafter proceed to decode the transmitted symbol. In this paper, we explore some efflcient solutions for signaling methods employing floating signal constellations.