An Efficient(k,p) Notational System Transform Algorithm

多进制编码和混合进制编码广泛应用于信息隐藏领域,影响其编码性能的一个关键因素是进制转换效率.针对任意k进制序列到P进制序列的相互转换,提出一种高效的进制转换算法,并根据信息论证明了其最优性.利用新算法改进了kT-lEX文本隐写系统、网页等价标记隐写术、图着色编码和APPM编码等多种基于混合进制编码和分组多进制编码的隐写术,有效提高了原方法的隐写性能.理论分析和实验结果均表明了该算法的有效性.Muti-ary codes and mix-ary codes are widely used in information hiding, while the transfer efficiency between notational systems is an important factor of coding efficiency.An effective notational system transfer algorithm based on double-coding method is proposed for transforming arbitrary k-ary sequences to p-ary sequences.It is proved that the proposed notational system transform algorithm is optimal.The method is applied to improve embedding efficiency of several kinds of steganographic algorithms based on mix-ary codes or grouped multi-ary codes, including KT-Lex steganographic system, webpage steganography based on equal tag, grid coloring codes and APPM codes.Both theory analysis and experimental results show that the proposed method is effective.国家自然科学基金(No.60803155;No.60970141;No.60902102;No.61274133); 中国科学院战略性先导专项课题基金(No.XDA06030601); 国家重大科技专项基金(No.2010ZX03004-003); 郑州市科技创新团队项目基金(No.10CXTD150)资

An Efcient Adaptive Image Steganographic Method for ± k Embedding

自适应隐写可避免修改载体的敏感区域,有效提高隐写术的安全性.总结分析了现有自适应隐写的边信息同步方法.通过推广单调纹理函数思想,构造一种基于自由度的纹理保序函数,实现了自适应隐写边信息的快速同步.结合湿纸编码和多层嵌入思想,提出自适应±1和±2隐写算法.新算法既保证通信双方能快速同步边信息,同时具有很高的抗检测性能.理论分析和实验结果均表明了算法的有效性.Adaptive steganography which avoids changing the sensitive area in carrier, can efectively improve the security of steganography.Firstly, the schemes of side information synchronization in adaptive steganography are summarized and analyzed.Secondly, using the freedom degree which is extented by the previous one-way texture functions, a new orderpreserving texture function as side information of adaptive steganography is constructed.Finally, by combining wet paper codes and the method of multi-layered embedding, ± 1 algorithm and ± 2 algorithm are proposed.The proposed scheme can efciently enhance the security of adaptive steganography while maintaining fast side information synchronization between communicators.Theoretical analysis and experimental results show the efciency of the proposed scheme.国家自然科学基金(60803155;61170234;60970141;60902102;61274133); 郑州市科技创新团队项目(10CXTD150); 中国科学院战略性先导专项课题(XDA06030601); 国家重大科技专项(2010ZX03004003)资助~