摘要
提出了一种新的矢量量化(VQ)数字图像水印算法。该算法所采用的矢量量化器基于关联的双码书结构,双码书分别是传统的基本码书和带标记位的新型扩展码书。在扩展码书中引入了表示水印信息位段的开始与结束标志,可以为每个水印像素动态地分配不等长的字符串。对于信道误差引起的含水印索引丢失,该算法具有良好的鲁棒性。同时,在嵌入以小像素值居多的非二值水印时,可以减少媒体图像块的需求,从而减少了因嵌入水印带来的额外失真。实验结果表明该算法具有良好的性能。
A novel VQ-based digital image watermarking algorithm is proposed.The algorithm uses the new vector quantizer based on associated dual codebooks composed of basic codebook and novel extended codebook with signs.Since two signs are introduced to indicate the beginning and ending of every segment of watermark information,the length of the character string assigned to every watermark pixel can be unequal.The method is robust against the channel error,thus causing loss of watermarked indices.Meanwhile,most pixel values are small for nonbinary watermark,so the total number of demanded image blocks and the extra distortion of the watermarked image can be decreased.Experimental results demonstrate the effectiveness of the algorithm.
出处
《数据采集与处理》
CSCD
北大核心
2008年第2期146-152,共7页
Journal of Data Acquisition and Processing
基金
中国科学技术大学青年基金(KB2506)资助项目
关键词
数字水印
矢量量化
信道误差
鲁棒性
digital watermarking
vector quantization
channel error
robustness
