嵌入式数字水印图像仿真研究

Simulation of Embedded Digital Watermark Image

数字水印问题的研究中,在充分考虑图像失真与水印嵌入信息量的基础上,为了保证图像水印的稳健性和安全性,提出一种基于JND门限的水印嵌入算法,在嵌入水印时,将宿主图像与水印图像作适当层次的小波分解,将宿主图像的小波变换系数做基于门限值的修改,为了避免小系数对图像处理产生的PSNR的影响,对PSNR的计算公式采用阈值化处理,在提高水印嵌入冗余的同时保证水印的隐蔽性。考虑到灰度水印嵌入的水印信息量大,通过合理设计强度因子,在不影响水印透明性的情况下最大化嵌入水印的强度和信息量。应用本算法进行仿真。结果表明,对常见图像作水印嵌入处理能够得到很好的鲁棒性和隐蔽性,得到很好的水印嵌入效果。

Taking full account of the image distortion and the watermark embedding based on the amount of information,JND threshold is proposed based on the watermark embedding algorithm.In the embedded watermark,the appropriate level of wavelet decomposition is carried out with the host image and watermark image The host image wavelet coefficients changes based on threshold to modify the coefficients of the location and parameters.In order to avoid the small coefficient generated by the impact of PSNR in the image processing,the formula for calculating PSNR threshold processing is used.The watermark embedding redundancy is increased while ensuring the invisibility of the watermark.Taking into account the fact that gray watermark has the largest embedding information,through the rational design of strength factor,the intensity and the amount of information embedded in the watermark are maximized under the condition that watermark transparency does not be affected.Experimental results show that the proposed algorithm for watermark embedding of common image is of very good robustness and invisibility.The watermark embedding effect is well.