基于混沌映射的鲁棒性公开水印

提出了一种新的DCT(discrete cosine transform)域鲁棒性公开水印算法.该算法利用混沌随机性好和容易再生的特性,首先用散列处理后的混沌序列置乱水印,而后基于混沌序列在宿主图像DCT域的中频带随机选择少量参考点,并在其邻域内用奇偶量化法批量嵌入乱序水印比特.多级混沌密钥的使用与频域系数修改的隐蔽性,加强了水印信息的保密性,在保证隐藏较大容量的有意义二值水印图像的同时,实现了水印信息的盲提取,并在水印的不可见性与鲁棒性之间达到了合理的折衷.

Robust Public Watermarking Based on Chaotic Map

A new robust public watermarking algorithm in DCT (discrete cosine transform) domain is presented. Due to good randomness and easy reproducibility of chaos, the watermark is firstly permuted by the hashed chaotic sequence, then a small number of reference points are randomly selected in the middle frequency bands of the DCT domain based on the chaotic sequences, and the batch-type disorder watermark bits are embedded into the neighborhood of every reference point using odd-even quantization. The usefulness of multilevel chaotic keys and privacy of modification to frequency coefficients enhance the security of watermark information. The blind extraction of watermarking information is realized under guaranteeing that a larger capacity and significant binary watermark is hidden. Moreover, a reasonable trade-off between the invisibility and robustness is obtained.