Barni M, Bartolini F, Piva A
Dept. of Inf. Eng., Siena Univ., Italy.
IEEE Trans Image Process. 2001;10(5):783-91. doi: 10.1109/83.918570.
A watermarking algorithm operating in the wavelet domain is presented. Performance improvement with respect to existing algorithms is obtained by means of a new approach to mask the watermark according to the characteristics of the human visual system (HVS). In contrast to conventional methods operating in the wavelet domain, masking is accomplished pixel by pixel by taking into account the texture and the luminance content of all the image subbands. The watermark consists of a pseudorandom sequence which is adaptively added to the largest detail bands. As usual, the watermark is detected by computing the correlation between the watermarked coefficients and the watermarking code, and the detection threshold is chosen in such a way that the knowledge of the watermark energy used in the embedding phase is not needed, thus permitting one to adapt it to the image at hand. Experimental results and comparisons with other techniques operating in the wavelet domain prove the effectiveness of the new algorithm.
提出了一种在小波域中运行的水印算法。通过一种根据人类视觉系统（HVS）特性对水印进行掩蔽的新方法，相对于现有算法提高了性能。与在小波域中运行的传统方法不同，掩蔽是通过逐像素考虑所有图像子带的纹理和亮度内容来完成的。水印由一个伪随机序列组成，该序列被自适应地添加到最大细节频带中。与通常情况一样，通过计算水印系数与水印编码之间的相关性来检测水印，并且以不需要知道嵌入阶段所用水印能量的方式选择检测阈值，从而允许将其应用于手头的图像。实验结果以及与在小波域中运行的其他技术的比较证明了新算法的有效性。
