东南大学学报（自然科学版）2011，Vol.41Issue(2)：312-316,5.DOI:10.3969/j.issn.1001-0505.2011.02.019
基于共轭对称列率复数哈达玛变换的水印算法
Waterma rking algorithm based on conjugate symmetric sequency-ordered complex hadamard transform
摘要
Abstract
To improve the robustness and computation efficiency of watermark, a watermarking algorithm based on conjugate symmetric sequency-ordered complex hadamard transform (CS-SCHT)is proposed. In this algorithm, the host image is decomposed into blocks which are selected to find suitable blocks for watermark. Before embedding, the selected blocks are classified into two classes,flat or textured, corresponding to different quantization step for better robustness. Finally, the binary meaningful watermark is embedded into the phases of the blocks by quantization and spread spectrum technique. In order to resist de-synchronization attacks, a strategy to judge affine transformation by relying on the relationship between geometric moments before and after attacks is put forward. The transformation parameters can be computed and then applied to restore the synchronization of the host image. Experimental results show that the extracting watermark suffered attacks is still legible, indicating that the new algorithm has good robustness when transparence is satisfied. Meanwhile, whether the host image suffers de-synchronization attacks existence and what the attacks are can be exactly judged.关键词
共轭对称列率复数哈达玛变换/共轭对称/去同步攻击/仿射变换/检测阈值Key words
conjugate symmetric sequency-ordered complex hadamard transform (CS-SCHT)/ conjugate symmetric/ de-synchronization attack/ afline transformation/ detection threshold分类
信息技术与安全科学引用本文复制引用
张悦,舒华忠..基于共轭对称列率复数哈达玛变换的水印算法[J].东南大学学报（自然科学版）,2011,41(2):312-316,5.基金项目
国家自然科学基金资助项目(60873048)、江苏省自然科学基金资助项目(BK2008279). （60873048）
