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11. 发明专利

DE602005008943D1 未知
公开(公告)号：DE602005008943D1
公开(公告)日：2008-09-25
申请号：DE602005008943
申请日：2005-04-21
申请人： KONINKL PHILIPS ELECTRONICS NV
发明人： LANGELAAR GERRIT C
IPC分类号： G06T1/00
摘要： Disclosed is a method of embedding both a robust and a fragile watermark in an information signal which is compressed so as to include first signal samples having a first given value and further signal samples having a different value, wherein embedding the robust watermark. The method comprises the steps of: modifying signal samples in accordance with a watermark pattern if the act of modifying results in the modified signal sample assuming the first value; and wherein embedding the fragile watermark comprises the steps of: counting the number of 'ones' remaining (R) in the signal as a result of embedding the robust watermark; counting the number of 'ones' discarded (D) from the signal as a result of embedding the robust watermark; and determining a fragile payload on the basis of said remaining (R) and discarded (D) 'ones'.

12. 发明专利

AT325507T 未知
公开(公告)号：AT325507T
公开(公告)日：2006-06-15
申请号：AT02743521
申请日：2002-07-02
申请人： KONINKL PHILIPS ELECTRONICS NV
发明人： STEENHOF FRITS A , LANGELAAR GERRIT C
IPC分类号： H04N7/30 , G06T1/00 , H03M7/40 , H04N1/32 , H04N7/08 , H04N7/081 , H04N7/26
摘要： A method and arrangement are disclosed for processing a compressed media signal, for example, embedding a watermark in an MPEG2 video signal. The watermark, a spatial noise pattern (140), is embedded (123) by selectively discarding the smallest quantized DCT coefficients. The discarded coefficients are subsequently merged in the runs of other run/level pairs. To compensate for a too large reduction of the bit rate, some of the new run/level pairs are not variable-length encoded (124) but represented by longer code words according to further coding rule (125) providing such longer code words, for example, MPEG's "Escape coding".

13. 发明专利

PL376469A1 WATERMARKING OF A VARIABLE BIT-RATE SIGNAL 未知
公开(公告)号：PL376469A1
公开(公告)日：2005-12-27
申请号：PL37646903
申请日：2003-09-22
申请人： KONINKL PHILIPS ELECTRONICS NV
发明人： LANGELAAR GERRIT C
IPC分类号： H04N7/26
摘要： Methods and apparatus for embedding a watermark in an information signal (MPin) are described. The watermark embedding process is controlled by at least one embedding parameter. The value of the embedding parameter is dependent upon the bit-rate of the information signal (MPin).

14. 发明专利

PL361764A1 WATERMARKING A COMPRESSED INFORMATION SIGNAL 未知
公开(公告)号：PL361764A1
公开(公告)日：2004-10-04
申请号：PL36176401
申请日：2001-12-21
申请人： KONINKL PHILIPS ELECTRONICS NV
发明人： LANGELAAR GERRIT C
IPC分类号： G06T1/00 , G09C5/00 , H03M7/30 , H04N1/387 , H04N7/08 , H04N7/081 , H04N7/26 , H04N7/30 , H04N7/32
摘要： A method and arrangement are disclosed for embedding a watermark in an MPEG compressed video stream. The watermark (a spatial noise pattern) is embedded by selectively discarding the smallest quantized DCT coefficients. The discarded coefficients are subsequently merged in the runs of the remaining coefficients. The decision whether a coefficient is discarded or not is made on the basis of a pre-calculated watermark buffer and the number of already discarded coefficients per 8x8 DCT block. The advantages of this method are (i) a very simple bit rate control system and (ii) no need for drift compensation. The algorithm can be implemented in a very efficient manner with respect to memory requirements and computational complexity.

15. 发明专利

AU2002339625A1 WATERMARK EMBEDDING 未知
公开(公告)号：AU2002339625A1
公开(公告)日：2003-06-10
申请号：AU2002339625
申请日：2002-10-24
申请人： KONINKL PHILIPS ELECTRONICS NV
发明人： LANGELAAR GERRIT C
IPC分类号： H04N5/91 , G06T1/00 , G11B20/00 , G11B20/10 , H04N1/32 , H04N5/913 , H04N7/08 , H04N7/081 , H04N7/26
摘要： Advanced watermark embedders use psycho visual/acoustic models to minimize perception of the embedded watermark in media contents. However, it is expensive to implement such advanced watermark embedders in consumer appliances (3) such as DVD recorders. In accordance with the invention, embedding strength parameters (JND) are calculated (13) off-line at a remote location (1) and transmitted along with the media contents to the consumer appliance (3). A relatively simple embedder (33) uses the received parameters to control the strength of the watermark (36) to be embedded. The parameters may be accommodated in the transmitted signal as payload of a fragile watermark or as user data in an encrypted MPEG stream.

16. 发明专利

DE602004013457T2 未知
公开(公告)号：DE602004013457T2
公开(公告)日：2009-01-29
申请号：DE602004013457
申请日：2004-10-06
申请人： KONINKL PHILIPS ELECTRONICS NV
发明人： LANGELAAR GERRIT C
IPC分类号： G06T1/00
摘要： Watermark detectors have a buffer in which a number of image tiles are folded and accumulated prior to computing the correlation between buffer contents and the watermark pattern being looked for. The intention of the folding and accumulation process is to average out the video content while accumulating the embedded watermark energy. This no longer appears to hold for strongly compressed video, such as DIVX, which exhibits a lot of artificial noise and undesired similarity (block patterns). As a result thereof, correlation peaks are often below the threshold. In a similar manner, the compression affects scale detection. According to this invention, only frames (or parts thereof) that are not so heavily compressed and therefore have a high probability of carrying enough watermark energy are folded and accumulated. To this end, a quality metric is calculated, the quality metric being indicative of the degree of compression of the data. The quality metric may be calculated based on the compressed data itself or derived from the decompressed base-band data. An advantageous example is the number of non-zero DCT coefficients of a (residue) frame. A determination is then made as to whether to exclude the frame (or part thereof) from the watermark decode process. The quality metric may also be used to select data for use in a scale detection process.

17. 发明专利

DE602004013457D1 未知
公开(公告)号：DE602004013457D1
公开(公告)日：2008-06-12
申请号：DE602004013457
申请日：2004-10-06
申请人： KONINKL PHILIPS ELECTRONICS NV
发明人： LANGELAAR GERRIT C
IPC分类号： G06T1/00
摘要： Watermark detectors have a buffer in which a number of image tiles are folded and accumulated prior to computing the correlation between buffer contents and the watermark pattern being looked for. The intention of the folding and accumulation process is to average out the video content while accumulating the embedded watermark energy. This no longer appears to hold for strongly compressed video, such as DIVX, which exhibits a lot of artificial noise and undesired similarity (block patterns). As a result thereof, correlation peaks are often below the threshold. In a similar manner, the compression affects scale detection. According to this invention, only frames (or parts thereof) that are not so heavily compressed and therefore have a high probability of carrying enough watermark energy are folded and accumulated. To this end, a quality metric is calculated, the quality metric being indicative of the degree of compression of the data. The quality metric may be calculated based on the compressed data itself or derived from the decompressed base-band data. An advantageous example is the number of non-zero DCT coefficients of a (residue) frame. A determination is then made as to whether to exclude the frame (or part thereof) from the watermark decode process. The quality metric may also be used to select data for use in a scale detection process.

18. 发明专利

AU2003303771A1 EMBEDDING A WATERMARK IN A CODED SIGNAL 未知
公开(公告)号：AU2003303771A1
公开(公告)日：2004-08-13
申请号：AU2003303771
申请日：2003-12-16
申请人： KONINKL PHILIPS ELECTRONICS NV
发明人： LANGELAAR GERRIT C
IPC分类号： G06T1/00
摘要： Method and arrangement for water(re)marking a compressed video signal by modifying selected DCT coefficients. To avoid that the bitrate is thereby reduced too much, selected variable-length codewords are represented by escape codes. In order to avoid that ESC codes increase the bitrate too much (an ESC code is 7-21 bits longer than the corresponding VLC word), the bitrate is controlled in units of small data chunks. While a VLC is processed, a table is filled with candidate ESC codes. The bitrate controller tries to make the difference between original and processed data chunks zero by re-encoding one VLC into an appropriate ESC code.

19. 发明专利

AU2002348910A1 EMBEDDING A WATERMARK IN AN IMAGE SIGNAL 未知
公开(公告)号：AU2002348910A1
公开(公告)日：2003-06-17
申请号：AU2002348910
申请日：2002-11-13
申请人： KONINKL PHILIPS ELECTRONICS NV
发明人： LANGELAAR GERRIT C
IPC分类号： G06T1/00 , G06T9/00 , H04N1/387 , H04N7/08 , H04N7/081 , H04N7/26
摘要： A method and arrangement are disclosed for embedding a watermark (W) in a media signal (MP) comprising signal samples (x(n)) being encoded as variable-length code words (VLC). The variable-length coded DCT coefficients of an MPEG2 video signal constitute such a media signal. The watermark is embedded by inverting the signs of the AC coefficients as far as such an inversion indeed causes the coefficients to be increased or decreased as prescribed (s(n)) by the watermark to be embedded. The invention is simple to implement, does not require re-encoding of the signal and does not affect the bit rate of the bit stream.

20. 发明专利

BR0109448A 未知
公开(公告)号：BR0109448A
公开(公告)日：2003-06-03
申请号：BR0109448
申请日：2001-12-21
申请人： KONINKL PHILIPS ELECTRONICS NV
发明人： LANGELAAR GERRIT C
IPC分类号： G06T1/00 , G09C5/00 , H03M7/30 , H04N1/387 , H04N7/08 , H04N7/081 , H04N7/26 , H04N7/30 , H04N7/32
摘要： A method and arrangement are disclosed for embedding a watermark in an MPEG compressed video stream. The watermark (a spatial noise pattern) is embedded by selectively discarding the smallest quantized DCT coefficients. The discarded coefficients are subsequently merged in the runs of the remaining coefficients. The decision whether a coefficient is discarded or not is made on the basis of a pre-calculated watermark buffer and the number of already discarded coefficients per 8x8 DCT block. The advantages of this method are (i) a very simple bit rate control system and (ii) no need for drift compensation. The algorithm can be implemented in a very efficient manner with respect to memory requirements and computational complexity.

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