发明授权
US08970910B2 Visible and invisible watermarking of printed images via 2nd generation stochastic seed frequency modulation
有权
通过第二代随机种子频率调制的可见和不可见的水印印刷图像
- 专利标题： Visible and invisible watermarking of printed images via 2nd generation stochastic seed frequency modulation
- 专利标题（中）： 通过第二代随机种子频率调制的可见和不可见的水印印刷图像
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申请号： US13313329申请日： 2011-12-07
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公开(公告)号： US08970910B2公开(公告)日： 2015-03-03
- 发明人: Edgar A. Bernal , Shen-ge Wang , Robert P. Loce , Zhigang Fan
- 申请人： Edgar A. Bernal , Shen-ge Wang , Robert P. Loce , Zhigang Fan
- 申请人地址： US CT Norwalk
- 专利权人： Xerox Corporation
- 当前专利权人： Xerox Corporation
- 当前专利权人地址： US CT Norwalk
- 代理机构： Fay Sharpe LLP
- 主分类号： H04N1/405
- IPC分类号： H04N1/405 ; G06K15/00
摘要：
As set forth herein, computer-implemented methods and systems facilitate watermarking documents and/or images using 2nd generation stochastic halftoning. The watermark is used to spatially vary the gray level at which a frequency modulation-to-amplitude modulation transition occurs. The encoding algorithm uses as inputs a contone image and a watermark. The visibility of the watermark is controlled by the magnitude of the difference between the AM-to-FM transition threshold values.