发明授权
US06975733B1 Watermarking of digital images using wavelet and discrete cosine transforms
有权
使用小波和离散余弦变换对数字图像进行水印
- 专利标题: Watermarking of digital images using wavelet and discrete cosine transforms
- 专利标题(中): 使用小波和离散余弦变换对数字图像进行水印
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申请号: US09786823申请日: 1999-09-10
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公开(公告)号: US06975733B1公开(公告)日: 2005-12-13
- 发明人: Jong Uk Choi , Jong Won Kim , Jung Suck Cho , Han Ho Lee
- 申请人: Jong Uk Choi , Jong Won Kim , Jung Suck Cho , Han Ho Lee
- 申请人地址: KR Seoul
- 专利权人: Markany, Inc.
- 当前专利权人: Markany, Inc.
- 当前专利权人地址: KR Seoul
- 代理机构: Senniger Powers
- 国际申请: PCT/US99/20649 WO 19990910
- 国际公布: WO00/16516 WO 20000323
- 主分类号: G06K9/00
- IPC分类号: G06K9/00
摘要:
The present invention relates to a method for embedding a watermark into a black and white or color digital image [D(x)]. Basically the inventive method comprises the steps of transforming the digital image using a wavelet transform [WC(y)], transforming a watermark using discrete cosine transform (DCT), integrating the wavelet-transformed digital image with the DCT-transformed watermark [DW(x)+WC(y)] to insert the watermark into the image, and generating the watermarked image using inverse wavelet transform [D(x)′]. For color images, RGB mode is converted into YIQ mode using a conversion matrix and the wavelet transform is applied to the Y-, I-, Q-values. This inventive digital watermarking of a color image is found to be highly robust against lossy compression and other image processing operations, compared to conventionally known methods which are known to be unsuitable for watermarking color images.
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