The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 05, 2008
Filed:
Nov. 20, 2003
Yasuyuki Nomizu, Kanagawa, JP;
Hiroyuki Sakuyama, Tokyo, JP;
Junichi Hara, Kanagawa, JP;
Nekka Matsuura, Kanagawa, JP;
Takanori Yano, Kanagawa, JP;
Taku Kodama, Kanagawa, JP;
Toshio Miyazawa, Kanagawa, JP;
Yasuyuki Shinkai, Kanagawa, JP;
Takayuki Nishimura, Tottori, JP;
Yasuyuki Nomizu, Kanagawa, JP;
Hiroyuki Sakuyama, Tokyo, JP;
Junichi Hara, Kanagawa, JP;
Nekka Matsuura, Kanagawa, JP;
Takanori Yano, Kanagawa, JP;
Taku Kodama, Kanagawa, JP;
Toshio Miyazawa, Kanagawa, JP;
Yasuyuki Shinkai, Kanagawa, JP;
Takayuki Nishimura, Tottori, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A digital watermarking technique is disclosed, in which image data are converted to frequency components through discrete wavelet transform and quantized into a set of quantized coefficients, which are then divided into a plurality of blocks. A digital watermark is embedded in the quantized coefficients by performing ON/OFF adjustment of bit information, such that the relation between natural number T and the bit information defined by N (N is an even number) significant bits Qnm (x, y) of the m-th bit plane of the n-th block satisfies the ON state represented by equation (1), or the OFF state represented by equation (2), depending on whether the hash value of the n-th block is odd or even. Then the quantized coefficients are encoded to produce a code stream.