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.
出处
《光电子．激光》
EI
CAS
CSCD
北大核心
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)
