随着信息技术的迅猛发展，数字作品的知识产权保护和信息的安全性愈来愈越重要。本文提出一种基于小波变换的图像双水印算法，首先运用HAAR小波对原始图像亮度分量进行三层离散小波变换，并运用Arnold 变换和二维超混沌模型对识别水印进行混沌加密；然后结合小波域内的JND模型，在低频分量中嵌入识别水印，并运用同一密钥在水平分量中嵌入确认水印。实验结果表明,该双水印算法具有良好的不可见性、鲁棒性和安全性，能有效提高图像版权的认证、保护能力。

With the rapid development of information technology, digital media intellectual property protection and information security are more and more important. In this paper, an image dual watermarking algorithm based on wavelet transform is proposed.First, the luminance component of original image is subjected to three discrete wavelet transforms (DWT) by HAAR wavelet. And the watermark is identified for chaotic encryption by Arnold transform and two-dimensional hyper-chaotic model. Then, the watermark is embedded in the low frequency component according to the JND model. And the watermark is embedded in the horizontal component according to the same key. The experimental results show that the double watermarking algorithm has good invisibility,robustness and security, and can effectively improve the image copyright authentication and protection ability.