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EP0935872B1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Watermarking an information signal

Assignee: Koninklijke Philips NV
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Filing: 1998-08-17
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Granted: 2001-11-21
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Expires: 2018-08-17
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Abstract

No abstract record available.

Inventors

  • 👤 Johan Paul Marie Gerard Linnartz

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-10 02:31
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/91; H04N5/913; G; G06; G06T; G06T1/00; G06T1/0021; G06T1/005; H04N1/00; H04N1/00002; H04N1/00005; H04N1/00026; H04N1/00037; H04N19/00; G06T2201/00; G06T2201/005; G06T2201/0051; G06T2201/0061; G06T2201/0065; G06T2201/0083

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 105 words
A method of detecting a multi-bit watermark in a signal, each bit (w(n)) of said multi-bit watermark being represented by a respective watermark subpattem, comprising the steps of: determining (21,22), for each watermark subpattern, a correlation value (y(n)) indicating the extent to which said subpattern is present in the signal; combining (24,23) said correlation values to detect (D) whether the watermark is present in the signal irrespective of its multi-bit value; and comparing (25) said correlation values (y(n)) and the corresponding bits (w(n)) of an applied multi-bit value to obtain an indication (M) of to which extent the detected watermark has said applied multi-bit value.
Claim 2
Dependent Claim 33 words
A method as claimed in claim 1, wherein said step of comparing comprises calculating the sum of squares of differences between each correlation value and the corresponding bit of the applied multi-bit value.
Claim 3
Dependent Claim 69 words
A method as claimed in claim 1, wherein the signal is a video image which is watermarked by adding a watermark pattern to said image, the video image and the watermark pattern being divided into blocks, the blocks of the watermark pattern constituting said subpatterns, and wherein each bit of the multi-bit value is represented by whether or not a subpattern has been added to a corresponding image block.
Claim 4
Dependent Claim 108 words
An arrangement for detecting a multi-bit watermark in a signal, each bit (w(n)) of said multi-bit watermark being represented by a respective watermark subpattern, comprising: means for determining (21,22), for each watermark subpattern, a correlation value (y(n)) indicating the extent to which said subpattern is present in the signal; means for combining (24,23) said correlation values to detect (D) whether the watermark is present in the signal irrespective of its multi-bit value; and means for comparing (25) said correlation values (y(n)) and the corresponding bits (w(n)) of an applied multi-bit value to obtain an indication (M) of to which extent the detected watermark has said applied multi-bit value.
Claim 5
Independent Claim 68 words
A method of embedding a multi-bit watermark in a video image by adding a watermark pattern to said image, comprising the steps of: dividing (11,12) the video image and said watermark pattern into blocks, the blocks of the watermark pattern constituting subpatterns; and representing (10) each bit (w 1 ..w n ) of the multi-bit value by adding or not adding a subpattern to the corresponding image block.
Claim 6
Dependent Claim 73 words
An arrangement for embedding a multi-bit watermark in a video image (P) by adding a watermark pattern (W) to said image, comprising: means for dividing (11,12) the video image and said watermark pattern into blocks, the blocks of the watermark pattern constituting subpattems; and means for adding (10) or not adding a subpattem to a corresponding image block in accordance with a corresponding bit (w 1 ..w n ) of the multi-bit value.

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