简洁的JPEG图像隐写DCT系数选择方案和安全性增强策略

根据图像JPEG压缩的特点，提出了一种简洁有效的DCT系数选择方案，不仅充分利用了非零交流DCT系数，而且还用到部分零值DCT系数；此外，通过改变系数的嵌入顺序，优先考虑低频系数，改善了算法的安全性。实验表明，将2种典型的空域隐写算法（EPES和APPM）应用到所提出的算法框架，获得了比3种经典压缩域隐写算法（JSteg、F5和nsF5）和新近提出的基于STC框架的DCT域隐写算法（LPD）更大的嵌入容量及更好的安全性。所提出的 DCT 系数选择和嵌入框架可有效提升嵌入容量和抗隐写分析的性能，且所提方案具有通用性，可应用于不同隐写算法。

Succinct scheme of DCT coefficient selection towards enhanced security of JPEG image steganography

Based on the characteristics of JPEG compression,a succinct and effective scheme of DCT coefficients selection was proposed,in which not only the non-zero AC coefficients but also part of the zero coefficients were exploited.Moreover,the scheme embedded messages in a different order than the conventional practice and gave priority to the low frequency coefficients so as to achieve enhanced security.The embedding manners of two typical steganographic algorithms(EPES and APPM)were extended from the spatial to the compression domain and the proposed scheme was applied to them for coefficient selection and embedding.Experimental results showed that larger capacity and better security were achieved compare to three classical steganographic algorithms(JSteg,F5 and nsF5)and one current steganographic algorithm based on STC framework(LPD).The proposed coefficient se-lection and embedding scheme can effectively improved the performance of some classic DCT domain steg-anographic methods in terms of capacity and security.The scheme was general and could be easily applied to dif-ferent steganography methods.