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公开(公告)号：WO2008052430A1
公开(公告)日：2008-05-08
申请号：PCT/CN2007/003035
申请日：2007-10-24
Applicant: 北大方正集团有限公司 , 北京大学 , 北京北大方正电子有限公司 , 亓文法 , 李晓龙 , 张华
IPC: G06T1/00
CPC classification number: G06T1/005 , G06T2201/0051 , G06T2201/0062 , H04N1/32203 , H04N1/32229 , H04N1/32261
Abstract: A method of digital watermark embedding and extracting and device thereof in the text images of black-and-white binary value are disclosed. The embedding method includes: locating the regions of effective characters in the text image, grouping the regions of effective characters to account the number of black spots in each region, calculating the first pixel number needed to turn off in each character region according to the relative relationship of the number of black spots in each character region of each group, watermark information bit strings, and the first step length, and overturning the pixels in each region according to the first number. The extracting method includes: locating the regions of effective characters in the text image, grouping the regions of effective characters to account the number of black spots in each character region, extracting the embedded watermark information bit strings according to the relative relationship of the number of black spots in the character regions of each group and the first step length. The invention can better resist the attack of printing, scanning and copying, which has good visual effects and a lot of embedded information, and it has the better commonality in the field of digital printing.
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公开(公告)号：WO2009082987A1
公开(公告)日：2009-07-09
申请号：PCT/CN2009/070588
申请日：2009-02-27
Applicant: 北大方正集团有限公司 , 北京大学 , 北京北大方正电子有限公司 , 李晓龙 , 杨斌 , 程道放 , 亓文法
CPC classification number: G06T1/0021 , G06T2201/0051 , G06T2201/0061 , H04N1/32203 , H04N5/913 , H04N2005/91335
Abstract: A method and device for embedding a watermark into a digital image, the method includes the following parts. Total or part of pixels of the digital image to be embedded are divided into group. The contained pixels number of each group is greater than or equal to three. Bit stream strings of the watermark to be embedded are divided into group. Each group contains a watermark signal. The group number of the bit-stream strings of the watermark is the same as the group number of the digital image pixels. The corresponding changed pixel values signal of the pixel values signal is calculated based on each pixel value signal and the corresponding watermark signal and a digital signal. The pixel values of the corresponding group pixel values of the digital image are changed based on the changed pixel value signal in order to realize embedding the watermark. At the same time, a method and device for extracting the watermark are disclosed.
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Patent Agency Ranking
公开(公告)号：WO2007025423A1
公开(公告)日：2007-03-08
申请号：PCT/CN2006/000855
申请日：2006-04-29
IPC: G06T1/00
CPC classification number: H04N1/00846 , G03G21/046 , G03G2215/00932 , H04N1/00875 , H04N1/00883
Abstract: 本发明涉及一种文档的防拷贝方法，属于完全文档的保护技术领域。现有技术中，对于一些重要文档，特别是机密文档，由于资料完全保密，文件所有者常禁止拷贝该类文档，但是现有的技术还不能从根本上解决禁止拷贝的机密文档的非法拷贝问题。本发明所述的方法是在防拷贝文档中的原始图像下面嵌入防伪底纹，通过运行固化在拷贝设备中的应用程序检测防拷贝文档中隐藏的标记信息来判断是否可以合法拷贝该文档。采用本发明所述的方法，可以快速、准确地检测出防拷贝文档中的水印信息，从根本上切断了防拷贝文档被非法拷贝的途径，大大增强了防拷贝机密文档的安全系数，方法简单，不需要额外的硬件存储空间。
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公开(公告)号：WO2007062554A1
公开(公告)日：2007-06-07
申请号：PCT/CN2006/000858
申请日：2006-04-29
IPC: H04N1/387
CPC classification number: H04N1/32203 , H04N1/32219 , H04N1/32352 , H04N2201/3205 , H04N2201/3208 , H04N2201/3214 , H04N2201/3221 , H04N2201/3266 , H04N2201/3281 , H04N2201/3284
Abstract: Amethod and device for embedding digital watermarkinto a text document and detecting it, whichbelongs :o a technical art of document protection.The method and device are accomplished byrepeatedly printing a layer of shading forrecording a mass of watermarkinfromation at the bottom of the normal document idditionally, the shading composed of the grids arranged by a certainrule, the change of the grid's position recording the eachbit string inthe information flow of the watermark.With the method and device, it is possible to increase the amount of the hidden information, wherein the watermarkinformation embedded into the shading svill be diffused along with the document, ifnecessary, it is possible to detect afterthe document is digitized by a scanner.
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公开(公告)号：WO2012089109A1
公开(公告)日：2012-07-05
申请号：PCT/CN2011/084760
申请日：2011-12-27
Applicant: 北大方正集团有限公司 , 北京大学 , 北京北大方正电子有限公司 , 北京北大方正技术研究院有限公司 , 亓文法 , 韩书昌 , 王高阳 , 王立东 , 杨斌
CPC classification number: G06F3/1238 , G06F3/1222 , G06F3/1288 , G06F3/1289 , G06K15/4095 , H04L63/102 , H04L63/20 , H04L67/125 , H04L67/34
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公开(公告)号：WO2012083882A1
公开(公告)日：2012-06-28
申请号：PCT/CN2011/084577
申请日：2011-12-23
Applicant: 北大方正集团有限公司 , 北京大学 , 北京北大方正电子有限公司 , 北京北大方正技术研究院有限公司 , 王高阳 , 亓文法 , 王立东 , 杨斌
IPC: G06T1/00
CPC classification number: G06T1/0021 , G06K9/348 , G06K2209/01 , G06T2201/0051 , G06T2201/0062 , G06T2201/0083
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公开(公告)号：WO2006133615A1
公开(公告)日：2006-12-21
申请号：PCT/CN2006/000853
申请日：2006-04-29
IPC: B41M3/10
Abstract: 本发明涉及一种内嵌防复印底纹的安全文档的打印方法，属于文档打印技术领域。现有的防复印技术需要使用价格昂贵的防复印底纹印刷专用纸，而且防复印安全底纹设计的自由度比较低。本发明所述的方法将防复印安全底纹的生成模块集成在打印机驱动中，该模块通过接口函数向打印机驱动传递参数，则打印驱动程序会调用相应的功能模块生成含有防复印安全底纹的数字水印数据，并将该数据保存在页面描述文件中，然后将正常打印文档的数据和数字水印数据文件合并在一起，生成一个新的数据文件并打印。采用本发明所述的方法，可以实现防复印安全底纹和正常文档数据的同时打印，因此可以适用于普通纸，而且，可以自由地设计防复印安全底纹。
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