Z2Z4-ADDITIVE PERFECT CODES IN STEGANOGRAPHY

Steganography is an information hiding application which aims to hide secret data imperceptibly into a cover object. In this paper, we describe a novel coding method based on Z(2)Z(4)-additive codes in which data is embedded by distorting each cover symbol by one unit at most (+/- 1-steganography). This method is optimal and solves the problem encountered by the most efficient methods known today, concerning the treatment of boundary values. The performance of this new technique is compared with that of the mentioned methods and with the well-known rate-distortion upper bound to conclude that a higher payload can be obtained for a given distortion by using the proposed method