利用分集接收能够大幅度改善系统接收性能的原理,把彩色图像看成是多通道的通信信道,可读水印被正弦调制,并分别被混沌置乱,嵌入到彩色图像3个通道的小波域中。检测时,利用自适应谱线增强器对宽带信号和窄带信号的良好分离特性,采用LMS算法将调制水印自适应地从各信道中提取出来,并被数字累加,设计了数字水印相关接收机,达到了最优盲检测。实验结果证实了理论推导。
Based on the theory in which diversity can improve receiving performance, color image is regarded as multi-channel of communication. Readable watermark, modulated by sine wave, is chaos-scrambled and is embedded into wavelet domain of 3 channels of color image respectively. In detection, based on the good separation of ALE to broadband signal and narrowband signal, using LMS algorithm, the modulated watermarks will be extracted from channels adaptively and are accumulated. A correlation receiver of watermark is devised for the optimum blind detection. The experimental results validate the theoretic deduction.