提出了一种基于改进的扩频（improved spread spectrum，ISS）技术的盲水印算法，针对ISS技术局部嵌入失真不可控制的缺点，结合人类视觉系统模型（HVS模型）建立一个限失真的数学模型实现水印自适应最优嵌入。实验结果表明，提出的算法克服了ISS算法中局部失真大的问题，并且有比ISS算法更好的鲁棒性。水印图像在JPEG压缩、各种噪声、常见滤波的攻击下能够提取出水印信息，表现较强的鲁棒性。

In this paper, an ISS algorithm with adaptive parameters has been proposed. It takes into account the features of human visual system(HVS) and thus can limit the local distortion of the watermarked images. By doing this way, the watermarking scheme has better transparency and stronger robustness. Experimental results demonstrate that the proposed algorithm overcomes big local distortion existed in ISS scheme, and is robust enough against many kinds of image processing such as JPEG compression, noise filtering.