Image Steganography via Fully Exploiting Modification Direction
Xuejing Niu, Meng Ma, Rui Yin Tang, Zhaoxia Yin · International Journal of Security and Its Applications · 2015
Embedding bits by replacing pixel's least-significant bit (LSB) is a simple but great idea.Nevertheless, this method is not safe enough.Afterwards, a series of effective and safe algorithms which are based on LSB substitution method were proposed such as EMD (exploiting modification direction) and EMD-2.EMD, modifying at most one of n pixels' LSB to embed a 21 n -ary notational system number, achieved higher embedding efficiency than LSB method.EMD-2 modifys at most two of a group n pixels to embed a notational system number, making embedding capacity improved compared with EMD.To improve embedding capacity further, we proposed a new method EMD-3 exploiting modification direction fully.EMD-3 modifys a group of n pixels by 1 to embed a secret digit in 3 n -ary notational system.The experimental results demonstrate that EMD-3 can improve embedding capacity and preserve good image quality at the same time.Besides, EMD-3 is as secure as EMD and EMD-2.