在分析人类视觉系统(HVS)特征的基础上,提出了一种新型的分层数字水印技术.利用HVS对不同区域、不同局部特征的噪声敏感性不同,设置相应的区域水印权重和局部水印权重,将水印按照设置的分层权重嵌入到静态小波变换(SWT)后的细节子带中.利用所提出的新型多分辨率检测器,通过与传统的水印方法比较表明,该方法具有较好透明性和盲检测性;对于常见的压缩、中值滤波等图像处理攻击,该方法表现了很好的稳健性.
A novel hierarchical digital watermarking method, based on the properties of human visual system, is proposed. First the region watermark weights and local watermark weights are appropriately set based on the noise sensitivity properties of human visual system to different regions and local features. Watermark is then embedded into decomposed detail subbands of static wavelet transform. A new multiresolution detector is proposed for watermark detection. Experimental results and comparisons with other techniques operated in the wavelet domain prove the effectiveness of the new algorithm,including superior imperceptibility and robustness to common attacks such as image compression and median filtering.