基于新的失真代价函数的自适应JPEG隐写

为了提高隐写的安全性，提出了基于一种新失真代价函数的自适应JPEG 隐写算
法. 考虑到纹理区域更有利于信息嵌入，本算法通过非零量化DCT 系数的绝对值加权和来
度量DCT 子块的纹理程度，并引入均匀嵌入思想，设计出了一种新的失真代价度量函数；同
时利用STC（syndrome trellis codes）编码将嵌入修改均匀地分散在任意数量级的非零量化
DCT 系数上，实现了秘密信息自适应地嵌入到载体的纹理区域中. 实验结果表明，在同等低
嵌入率下，该方法的安全性优于同类隐写算法.

Adaptive JPEG Steganography Based on New Distortion Cost Function

To improve security of steganography, this paper proposes an adaptive steganographic
scheme for JPEG images based on a new distortion cost function. As texture areas
in a cover image are more suitable for information embedding, the sum of absolute values
of all non-zero quantized DCT coefficients in a DCT block is used to measure texture of
the block. Combining the previous uniform embedding scheme, a new distortion cost function
is defined. With syndrome trellis codes, embedding modification spreads uniformly
over DCT coefficients of all possible magnitudes, embedding secret data adaptively into
the texture areas in the cover. Experimental results show that the proposed scheme out
performs the prior arts in terms of security with the same low payload.