基于DCT的自适应盲数字水印

目的为提高彩色图像数字水印的抗攻击性能,提出一种新的、鲁棒性强的DCT自适应水印算法。方法算法中利用Arnold变换对水印图像进行预处理,自适应选择强度因子。根据DCT变换原理,并利用其DC系数的形成过程,不需进行DCT变换,在空域中便可计算出8×8分块的DC系数。根据DC系数修改量的分布特点,直接在空域中完成水印的嵌入。结果该数字水印算法具有良好的透明性和稳健性,同时对涂抹、旋转、剪切、叠加噪声等常见攻击具有较强的鲁棒性。结论该算法在保证水印隐蔽性的同时能够抵抗一定程度的攻击,满足版权保护和数字防伪的需要。

Self-Adaptive Blind Digital Watermarking Based on DCT

The work aims to put forward a new DCT self-adaptive watermarking algorithm with strong robustness to improve the anti-attack performance of color image digital watermarking. In the algorithm, Arnold transform was used to preprocess the watermark image, and the intensity factor was adaptively selected. According to the principle of DCT transform and by means of the formation process of its DC coefficient, DCT transform was not required and 8×8 blocked DC coefficient could be calculated in the spatial domain. According to the distribution characteristics of DC coefficient modifiers, the watermark embedding was directly completed in the spatial domain. The digital watermarking algorithm had good transparency and robustness, and it also had strong robustness regarding painting, rotation, cutting, superimposed noise and other common assaults. The algorithm can ensure watermark concealment and it is also able to resist a certain level of attacks, which meets the needs of copyright protection and digital anti-counterfeit.