一种基于超混沌系统的立体图像零水印算法

为了在不改变立体图像质量的前提下对立体图像实施版权保护,提出了一种基于超混沌离散系统的立体图像零水印算法. 该算法利用立体图像左右视点小波变换域低频子带视差的稳定性以及离散余弦变换直流系数稳定的特点构造了一种视差零水印. 在水印构造过程中,利用了超混沌离散系统的初始值敏感性、参数密钥空间大和动力学行为复杂等特性映射视差零水印的 位置信息,从而增强了水印算法的安全性.此外,还分析了水印安全性与水印容量之间的关系. 实验结果表明,该立体图像视差零水印算法对加噪、滤波、压缩、剪切、图像放大和缩小等各种对称和非对称攻击表现出了 较强的鲁棒性.

A zero-watermarking algorithm of stereoscopic image based on hyperchaotic system

In order to protect the copyright of stereoscopic images in the condition of the image quality, a zero-watermarking stereoscopic image algorithm is presented based on hyperchaotic system. In the proposed algorithm, disparity zero-watermark is constructed according to the stability of disparity between low frequency bands of wavelet decomposition of the left and the right views and direct coefficients of discrete cosine transform; in the process of zero-watermark construction, the zero-watermark position mapping according to the features of the sensitivity of hyperchaotic discrete system initial value, ampleness of parameter key space and complexity of dynamic behavior, enhances the security of algorithm. The relationship between security and watermark capacity is also analyzed. Experimental results show that the proposed algorithm is strong robust to noise, filtering, compression, and the shearing of asymmetrical and symmetrical attacks.