摘要
提出一种新的图像水印算法。首先运用正态隶属云模型优化载体图像分布,然后利用标准μ-律压扩函数把优化后的图像信号变换到对数域、进行均匀量化,再经反变换函数使量化结果回到原始域。算法根据载体信号分布计算最优量化参数μ,通过可控抖动调制引入水印安全密钥。还对算法性能进行分析,并基于著名测试图像仿真验证分析结果。算法是对现有对数量化方法的实质性改进,获得了更好的鲁棒性与不可感知性。
A new watermarking algorithm for images is proposed. The scheme applies normal membership cloud model to improve the distribution of cover images and then employs standard μ-law companding function to transform the improved image signal into a logarithmic domain, quantizes it uniformly and uses the reverse function to let the result signal return the original domain. The best μ-value can be calculated according to the distribution features of cover signals. The secure watermark keys can be introduced through controlled dither modulation. The performance of the proposed scheme is analyzed and simulation experiments are made based on 10 well-known test images. The previous logarithmic quantization methods improved scheme essentially and get better robustness and fidelity are obtained in the proposed scheme.
出处
《科学技术与工程》
北大核心
2013年第27期8027-8031,共5页
Science Technology and Engineering
基金
河北省科技计划项目(12210721)资助
关键词
图像水印
正态隶属云
对数量化
量化索引调制（QIM）
image-watermarking normal cloud logarithmic quantization quantization index modulation（QIM）
