Improving embedding efficiency by incorporating SDCS and WPC

Embedding efficiency, which is defined as the average number of secret data bits embedded per one embedding change, is an important attribute directly influencing the security of steganography. Higher embedding efficiency is usually expected to get more secure steganographic method. In this paper, by incorporating two previously introduced techniques: the ldquosum and difference covering setrdquo (SDCS) and the ldquowet paper coderdquo (WPC), a novel double-layered embedding method is presented. As compared with the original SDCS-based steganography, the novel method can embed more bits without introducing additional embedding distortion, therefore the embedding efficiency is improved. In summary, the proposed method provides some steganographic schemes with diverse embedding rates and good embedding efficiency.