基于离散余弦变换的数字水印技术

针对当前在开放的网络环境下对数字产品版权保护和认证来源及完整性的需求,在人们寻求办法保护他们在网络上传输的信息时,数字水印变得越来越重要,提出了基于离散余弦变换的数字图像水印方案。利用离散余弦变换嵌入的数字水印具有感官上的不可见性,并且原图像信息丢失量少,根据离散余弦变换抗几何变换的性质,使水印图像能够抵抗缩放和剪切等一系列攻击。具有很好的鲁棒性。并且能使用密钥较高精度地恢复水印。

The Digital Watermark Technique Based on Discrete Cosine Transform

Under the opening NT environment, the requirements of the authority and of digital works, the digital watermark is becoming increasingly important. As the previous embedding methods have some defects, we present a digital watermarking image method based on DCT. It makes the watermark perceptually invisible and there is few loss of relevant information of the original image. By using the properity of DCT, watermarking image is robust against attack, such as translation and cropping. And it can be retrieved with a high degree of accuracy by a secret key.