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
