Study on the robustness based on time and geometric distortion is a topic and a difficult point of digital watermark. This paper analyzes this phenomenon and proposes several countermeasures.

• 对时间和几何失真的鲁棒性的研究是数字水印技术当前研究的主题和难题,文章提出了解决这一难题的几种方法,并对这些方法进行了比较分析,得出结论,同时对这一难题提出展望。