Abstract: Most of existing DCT based image watermark algorithms are non-blind, and they usually embed watermarks into middle and low frequencies, but excluding DC component, of a DCT. This paper proposes a blocked DCT and quantization based blind image watermark algorithm. The algorithm is simple to understand and can be easily realized. Experimental results show that the algorithm has a good transparence of the embedded watermark image and is robust against attacks such as resampling, dithering, smoothing, noise adding, and JPEG-compression.

Key words: Digital watermark, DCT, Quantization, Blind watermark

摘要： 当前基于离散余弦变换(DCT)的图像数字水印方法大多为非盲的，水印一般嵌入DCT的中低频系数中，但却把DC分量排除在外。该文提出了一个基于分块DCT和量化的图像盲水印算法，将水印根据量化策略嵌入块DCT系数的DC分量中。该算法思想简单，步骤简便、容易实现。实验结果表明，该算法对嵌入的水印具有很好的透明性，对常见攻击如重采样、颜色抖动、平滑、加噪声和JPEG压缩等具有很强的稳健性。

关键词: 数字水印, 离散余弦变换, 量化, 盲水印

CLC Number: 

• TP39