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    Robust digital watermarking
    4.
    发明公开
    Robust digital watermarking 审中-公开
    强大的数字水印

    公开(公告)号：EP2306727A3

    公开(公告)日：2012-09-05

    申请号：EP10182728.5

    申请日：1999-06-23

    申请人： NEC Corporation

    发明人： Cox, Ingemar J. ,  Miller, Matthew L. ,  Oami, Ryoma

    IPC分类号： H04N7/24 ,  H04N7/26 ,  H04N1/32 ,  G06T1/00

    CPC分类号： G06T1/0028 ,  G06T1/0064 ,  G06T2201/0052 ,  H04N1/32154 ,  H04N1/32165 ,  H04N1/32192 ,  H04N1/32277 ,  H04N1/32304 ,  H04N7/24 ,  H04N19/467 ,  H04N21/8358 ,  H04N2201/3233 ,  H04N2201/327

    摘要： A watermarking procedure that is applicable to images, audio, video and multimedia data to be watermarked divides the data to be watermarked into a set of n x n blocks, such as the 8x8 blocks of MPEG. The same watermark signal can be distributed throughout the set of blocks in a large variety of ways. This allows the insertion algorithm to be changed without affecting the decoders. The decoding procedure first sums together the DUCT coefficients of N sets of 8x8 blocks to form a set of N summed 8x8 blocks and then extracts the watermark from the summed block. Since the sum of the DCT blocks is equal to the DCT of the sum of the intensity blocks, efficient decoding can occur in both the spatial and frequency domains.; The symmetric nature of the decoding process allows geometric distortions to be handled in the spatial domain and other signal distortions to be handled in the frequency domain. Moreover, insertion of a watermark signal into image data and the subsequent extraction of the watermark from watermarked image data which has been subject to distortion between the times of insertion and extraction involves the insertion of multiple watermarks designed to survive predefined distortions of the image data, such as panscan or letterbox mode transformations. Alternatively, a registration pattern in the image data, after the image data containing the registration pattern is subject to an unknown distortion, is used to compensate for distortion of the watermarked image data.

    Robust digital watermarking
    5.
    发明公开
    Robust digital watermarking 审中-公开
    强大的数字水印

    公开(公告)号：EP2306725A3

    公开(公告)日：2012-09-05

    申请号：EP10182704.6

    申请日：1999-06-23

    申请人： NEC Corporation

    发明人： Cox, Ingemar J. ,  Miller, Matthew L. ,  Oami, Ryoma

    IPC分类号： H04N7/24 ,  H04N7/26 ,  H04N1/32 ,  G06T1/00

    CPC分类号： G06T1/0028 ,  G06T1/0064 ,  G06T2201/0052 ,  H04N1/32154 ,  H04N1/32165 ,  H04N1/32192 ,  H04N1/32277 ,  H04N1/32304 ,  H04N7/24 ,  H04N19/467 ,  H04N21/8358 ,  H04N2201/3233 ,  H04N2201/327

    摘要： A watermarking procedure that is applicable to images, audio, video and multimedia data to be watermarked divides the data to be watermarked into a set of n × n blocks, such as the 8x8 blocks of MPEG. The same watermark signal can be distributed throughout the set of blocks in a large variety of ways. This allows the insertion algorithm to be changed without affecting the decoders. The decoding procedure first sums together the DCT coefficients of N sets of 8x8 blocks to form a set of N summed 8x8 blocks and then extracts the watermark from the summed block. Since the sum of the DCT blocks is equal to the DCT of the sum of the intensity blocks, efficient decoding can occur in both the spatial and frequency domains.; The symmetric nature of the decoding process allows geometric distortions to be handled in the spatial domain and other signal distortions to be handled in the frequency domain. Moreover, insertion of a watermark signal into image data and the subsequent extraction of the watermark from watermarked image data which has been subject to distortion between the times of insertion and extraction involves the insertion of multiple watermarks designed to survive predefined distortions of the image data, such as panscan or letterbox mode transformations. Alternatively, a registration pattern in the image data, after the image data containing the registration pattern is subject to an unknown distortion, is used to compensate for distortion of the watermarked image data.

    Method and apparatus for determining whether or not a reference pattern is present in a received and possibly watermarked signal
    6.
    发明授权
    Method and apparatus for determining whether or not a reference pattern is present in a received and possibly watermarked signal 有权
    用于确定基准图案是否被包括在所接收到的，并可能提供有水印信号的方法和装置

    公开(公告)号：EP2081188B1

    公开(公告)日：2012-03-14

    申请号：EP09150033.0

    申请日：2009-01-05

    申请人： Thomson Licensing

    发明人： Baum, Peter, Georg ,  Arnold, Michael ,  Gries, Ulrich ,  Voessing, Walter

    IPC分类号： G10L19/00 ,  G06T1/00

    CPC分类号： G10L19/018 ,  G06T1/0078 ,  G06T2201/0065 ,  H04N1/32154

    摘要： Many watermarking systems make use of correlation for calculating a detection metric, which means that several reference patterns are generated at encoder side and one or more of them are embedded inside the content signal, dependent on the message to be embedded. To decode the embedded message, it is necessary to discover which reference pattern was embedded at encoder side. This is determined by correlating the known reference patterns with the content signal. A watermark detector decides, depending on the size of the correlation result values, whether or not a given pseudo-random sequence was embedded. However, this does not provide correct decisions if watermarked audio is emitted by a loudspeaker and then captured with a microphone. According to the invention, it is taken advantage of the received signal echoes instead of treating them as noise. The watermark detection result is improved by integrating the correlation values resulting from echoes into the main correlation peak, thereby using correlation result amplitude values located within a predetermined neighbourhood of a correlation result peak amplitude value and exceeding a predetermined threshold.