Obtaining Higher Rates for Steganographic Schemes While Maintaining the Same Detectability

This paper focuses on modifying the decoder module for an active steganographic scheme to increase the effective data-rate without affecting the embedding module. Three techniques are suggested to improve the error correction framework, an essential component of an active steganographic scheme. The first involves puncturing where the code-length is increased by adding a suitable number of additional erasures. The second technique involves channel modeling and soft-decision decoding which is adaptive to the individual embeddable image coefficient. The third method adjusts the erasure threshold depending on the design hiding quantizer so as to achieve a higher data-rate. Combining these techniques, the effective data-rate is increased by 10%-50% for Yet Another Steganographic Scheme (YASS), a popular active steganographic scheme.