The main methods adopted include:1) watermark synchronization is achieved by invariant local circular regions which can be generated using image locally most stable feature points;
采取的主要方法有：1）利用图像中的局部最稳定特征点生成具有几何不变性的圆形特征区域，用于水印的同步；
In the extract process, through the decoding of the synchronization code to locate the position of the watermark signal embedded in the frame as well as data starting position.
在提取过程中，通过对同步码的解码来定位水印信号嵌入的帧位置以及数据起始位置。
The features of the proposed algorithm are as follows: (1) Synchronization code is embedded into audio with the watermark, and the watermark thus generated has the ability of self synchronization.
该算法具有如下特点：（1 ）在隐藏水印信息的同时，嵌入一个同步信号，使水印具有自同步能力；
The experiment result shows that the synchronization method can synchronize the detector with the watermark perfectly and that the watermark is robust to affine transformation attack.
实验表明，使用该方法能较好地恢复图像，有效地同步水印检测器与水印信号，从而使水印对仿射变换攻击具有鲁棒性。
It might fail to detect watermarking now that geometric attacks perform on a watermarked image and destroy the synchronization of the watermark signals embedded in the image.
几何攻击作用在加载有水印的图像上，水印同步信息被破坏，导致水印检测失败。
It might fail to detect watermarking now that geometric attacks perform on a watermarked image and destroy the synchronization of the watermark signals embedded in the image.
几何攻击作用在加载有水印的图像上，水印同步信息被破坏，导致水印检测失败。
应用推荐