Abstract: Watermarking is an effective method of multi-media copyright protection.This paper proposes a novel odd-even quantization watermarking algorithm，the quantization step is adaptively determined and controlled by Watson model and JPEG quantization table.The watermark is embedded in the mid-frequency coefficients of DCT.Because of odd-even quantization，watermark can be exacted very easily.Experimental results show the algorithm has good invisibility，and is robust to some common image processing and noise attacks.

Key words: digital watermarking, odd-even quantization, Watson model, JPEG quantization table

摘要： 数字水印是数字媒体版权保护的一种有效方法。提出了一种自适应的奇偶量化水印算法，其量化步长由Watson模型和JPEG量化表共同确定，并通过二者自适应地调节量化步长。水印在DCT的中频系数中嵌入，由于采用奇偶量化，水印提取方法简单。实验结果表明，该算法具有良好的不可见性，算法简单，并能抵抗常规的图像处理和噪声攻击，具有很强的鲁棒性。

关键词: 数字水印, 奇偶量化, Watson模型, JPEG量化表