Two fundament methods for time delay estimation are the correlation method and the phase method. 时延估计的基本方法是互相关法和相位谱法。
The watermark is a pseudo-random sequence and its existence can be judged by calculating the correlation of the original sequence and the detected sequence. 检测时通过计算原始随机序列与恢复出的随机序列的互相关来判断水印是否存在。
