摘要： 提出了一种用于版权保护和版权跟踪的图像水印算法。选取分块HT 的变换系数作为水印嵌入的特征集，通过密钥控制下的具体区间的选择和多步长的量化嵌入，实现了多水印的不可感知性和鲁棒性的优化。对二值水印图像进行Arnold 变换，提高了水印的安全性和鲁棒性。水印的提取不需要原始图像。实验结果表明，该算法满足水印的隐蔽性，对常用的信号处理操作和几何失真具有鲁棒性。

关键词: 吉林大学通信工程学院，长春 130025

Abstract: A blind image watermarking algorithm is proposed which is used for copyright protection and tracing. The block HT coefficients are selected as the watermark embedding feature collections, and the tradeoff between the imperceptibility and robustness are achieved by the segments selection under control of the keys and quantization embedding for multi-step. The image watermark is firstly Arnold transformed to enhance the security and robustness. Experimental results show that the proposed algorithm maintains the quality of the original image and is robust to common signal processing operations and geometrical distortions.

Key words: Image watermarking; Copyright tracing; Hadamard transform; Arnold