发明名称 |
Digital information embedding/extracting apparatus and method, and medium including a program for executing the method recorded thereon |
摘要 |
In an embedding apparatus, a transform section divides an original image into a plurality of blocks to perform orthogonal transform every block. An embedding section embeds a pseudo-random number sequence mapped with inherent digital information in part of a transform coefficients sequence obtained by the orthogonal transform using a weight sequence. In an extracting apparatus, a calculation section reads transform coefficients sequences for respective blocks from the data including the pseudo-random number sequence embedded therein in a predetermined order, and calculates an inner product between the transform coefficients sequences and a pseudo-random number sequence. A determination section determines that the pseudo-random number sequence has been embedded when the inner product is greater than a predetermined threshold value. A generation section extracts inherent digital information mapped with the determined pseudo-random number sequence. This method discourages deciphering of the digital information, suppresses image quality deterioration, and improves the detection rate of watermark data.
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申请公布号 |
US6788821(B2) |
申请公布日期 |
2004.09.07 |
申请号 |
US20010879136 |
申请日期 |
2001.06.13 |
申请人 |
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. |
发明人 |
INOUE HISASHI;KATSURA TAKASHI |
分类号 |
G06T1/00;H04N1/32;(IPC1-7):G06K9/46;H04N7/12 |
主分类号 |
G06T1/00 |
代理机构 |
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