此系统可以根据量化系数的选择不同而使水印信号的脆弱程度不同。由实验结果显示假如Q＝1，当图像受到高斯噪声的攻击时，已经不能通过系统的认证。-system can quantify the different coefficients so fragile watermark signals to different degrees. From the experimental results show that if the Q = 1, when images by Gaussian nois