In contrast with encryption , the existence of communication process and both communication sides is hided in the information hiding technique . even if the cover is intercepted by illegal users , the secret message can not be revealed because they do not know whether the secret message exists or not 与信息加密技术相比，它隐藏了通信过程及通信双方的存在，使得一些非法的窃取者即使截获一些信息，也无从下手，因为他们无法判断是否存在秘密信息。
With the rapid development of computer , network and communication , especially the popularization of the internet , information security and copyright protection have been a key and attractive problem . a potential solution to alleviate this problem is to use invisible digital watermarking scheme , which refers to the embedding of secret messages , unobtrusive marks or labels that can be represented as bits into the digital multimedia 基于计算机和网络的信息交换为多媒体数字作品的使用、传播提供了便利的途径，然而由于数字作品极易被非法复制和篡改的特性，使得数字作品的信息安全保护和版权保护成为迫切需要解决的实际问题。
Simulation results show that the methods we presented have better performance . 2 . data hiding in the digital image combined with hvs ( human visual system ) , we can put secret message in the image without degrading the quality for its redundancy and to secure the information 2数字图象中的信息隐藏由于数字图象中包含了大量的冗余信息，结合人的视觉特性，我们可以把一些重要的秘密信息隐藏于图象中，而不会引起图象的失真，达到了对信息进行秘密传输的目的，在很大程度上保护了秘密传输的消息。
In frequency domain , we research dct based information hiding techniques , and then give an adaptive technique , and a parity based approach in the dct domain , and an approach based on improved integration algorithm . we also propose an approach based on difference matrix in dct domain , and show all the approaches to embed / detect the secret messages , and their robust analysises 在频率域内，研究了基于dct变换的信息隐藏技术，提出了改进的dct自适应隐藏算法、 dct域奇偶性嵌入方法和改进的融合算法，同时提出了差值矩阵的dct域的隐藏算法，给出了这些算法的信息嵌入与恢复过程，并对频率域内的这些隐藏算法的鲁棒性进行了分析。
She reveals a beautiful world of private words formerly kept to herself . we do not know how much these secret messages and promises weight , or whether they are near or far from the present moment , or even whether they are real memories or simply a kind of yearning . these unspoken words not easily said to anybody have a hazy , powerful quality in au hoi - lams works 在《甜言蜜语》展览中，区凯琳尝试解开个人私密，将美丽的私言切语坦然道出，这些不易宣之于口的密语或承诺，是轻是重、是近是远、是回忆是憧憬已分不清，既朦胧却深刻。
