Saliency based image steganography with varying base SDS and multi-objective genetic algorithm

Hiding secret message into images is known as image steganography. A good image steganography method aims to minimize visual degradation while maximizing embedding capacity. In this paper, visual saliency is used to determine the number of bits which can be embedded in a pixel. The relation between the saliency of a pixel and the number of embedded bits is obtained by solving a multi-objective optimization problem. A genetic algorithm has been developed which gives the optimum relation between saliency values and the number of embedded bits in the pixels. A variation of Single Digit Sum (SDS) based steganography scheme has been used to embed the secret message bits where the base of computing SDS is estimated based on the number of bits being embedded in a pixel. Experimental results reveal that the proposed technique can boast of a good embedding capacity while controlling the visual degradation of stego image.