基于视觉特性的多比特量化水印方案  

Quantization Scheme Based on HVS for Multi-bit Watermarking

作　　者：张新鹏[1] 王朔中[1] 张开文[1] 

机构地区：[1]上海大学通信与信息工程学院,上海200072

出　　处：《光电子．激光》2003年第11期1179-1182,共4页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金资助项目(60072030);上海市重点学科建设资助项目(2001 44)

摘　　要：基于人类视觉特性(VHS),提出了一种新的量化水印方案。水印信息以量化方式嵌入在二层变换系数上,这些二层变换系数是由小波系数乘以不同权重、混洗后再进行离散余弦变换生成的。其中权值根据视觉特性确定,使得水印信号在高、低频部分的能量合理分配以保证较小的视觉失真。这种方法在无视觉失真的条件下可以保证较好的嵌入量和稳键性。定量地分析了信息量、隐蔽性和稳健性三者的关系,并用模拟实验验证了这些结果。Multi-bit watermarks can be embedded into host media using quantization index modulation (QIM). A novel watermarking technique in which coefficients in the double-layered transform domain were modified using an HVS-based quantization scheme. The double-layered transform coefficients were generated by discrete-cosine transforming (DCT) the weighted and pseudo-randomly permuted wavelet components. The weights were obtained according to the human visual system so that the watermark energy is properly distributed in different frequency bands leading to a lower visual distortion. This technique can provide a good robustness and high capacity of embedded mark without any visual distortion. Relations between embedding capacity, imperceptibility and robustness were analyzed and verified with simulation results.

关 键 词：视觉特性 数字水印 量化 二层变换系数 离散余弦变换 权值 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]