An Adaptive JPEG Steganographic Scheme Based on the Block Entropy of DCT Coefficients

Minimizing the embedding impact is a practically feasible philosophy in designing steganographic systems. The development of steganographic systems can be formulated as the construction of distortion profile reflecting the embedding impact and the design of syndrome coding based on a certain code. The authors devise a new distortion profile exploring both the block complexity and the distortion effect due to flipping and rounding errors, and incorporate it in the framework of syndrome trellis coding (STC) to propose a new JPEG steganographic scheme. The STC provides multiple candidate solutions to embed messages to a block of coefficients while the constructed content-adaptive distortion profile guides the determination of the best solution with minimal distortion effect. The total embedding distortion or impact would be significantly reduced and lead to the less detectability of steganalysis. Extensive experimental results demonstrate that the proposed JPEG steganographic scheme greatly increases the secure embedding capacity against steganalysis and shows significant superiority over some existing JPEG steganographic approaches.