dct2_out

代码说明：

  数字水印(digitalwatermarking)是一种信息隐藏技术，它的基本思想是在数字图像、音频或视频等数字媒体作品中嵌入秘密信息，以便保护数字作品的版权、证明作品的真实可靠性、跟踪盗版行为或提供作品的附加信息。(Digital Watermarking (digitalwatermarking) is a kind of information hiding technology, its basic idea is in the digital image, audio or video digital media works, such as embedded secret information in order to protect the copyright of digital works to prove that the true reliability of the work, tracking piracy works or provide additional information.)