Unobtrusiveness and robustness are two elementary characteristics of watermarking technology. 不可见性和鲁棒性是数字水印的两个基本特征。
The paper discusses the essence characters of digital libraries and the technology problems faced during constructing digital libraries. 论述了数字图书馆的基本特征以及建设数字图书馆所面临的技术问题。
