A Scheme of Modulo-Based Capacity-improvement upon EMD Systems

To enlarge the capacity of the hidden secrete, a steganographic approach using modification pixels in conjunction with [1, -1] is proposed in this paper. The underlying concept of our scheme is that 3ⁿ variations of modification to n cover pixels correspond 3ⁿ possible values of a secret digit; and each secret digit is composed of k-bit binary strings, where k=lfloorlog₂ 3ⁿrfloor. Each secret is embedded into n cover pixels by modifying pixels of the least significant bit (1-LSB). Experimental results show that the maximum embedded ratio of our scheme is 1.59 times better than achieved by previous works. In other words, our scheme not only provides high capacity but also maintains stego-image quality equal to previous works.