通过对信号处理领域抖动调制原理的分析,并结合人类视觉系统的掩蔽效应,提出了一个DCT 域盲水印模型。在MATLAB 仿真环境中,针对二值图像水印,实现了水印的预处理、嵌入、提取以及F 范数下水印检测。在水印嵌入过程中,通过自动调节量化步长改善了水印的透明性,水印检测时无需原始宿主图像,实现了盲检测,而且省略了反余弦变换过程,降低了算法复杂度。仿真实验表明,水印算法在JPEG 高强度压缩、剪切、各种噪声叠加以及多重水印等攻击下具有高鲁棒性。算法思想可应用于数字版权保护以及隐秘通讯等领域。

Through analysis of dither modulation algorithm of signal processing and the masking effect of human visual system, a DCT domain blind watermark model was proposed. Watermark preprocessing, embedding, extraction, and F norm-based detection were realized for binary image watermarks in MATLAB simulation environment. The imperceptibility of watermark was improved through automatically adjusting the quantization step during watermarking. Blind detection of watermark was realized without the original host image and algorithm complexity was reduced by leaving out inverse discrete cosine transform process. The simulation results showed that the scheme has stronger robustness against conventional attacks such as higher JPEG compression, cropping, noise overlap, multiple watermarking, etc. This scheme can be applied in digital copyright protection and secret communications.