Increasing integrity of watermarks using robust features

• US 20050120220A1
• Filed: 12/09/2002
• Published: 06/02/2005
• Est. Priority Date: 12/21/2001
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Oostveen, Job Cornelis, Kalker, Antonius Adrianus Cornelis Maria
• Granted Patent: US 7,478,242 B2
• Time in Patent Office: Days
• US Class Current: 713/177
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 1/005 Robust watermarking, e.g. average attack or collusion attack resistant
• CPC Class Codes: G06T 1/0085 Time domain based watermarking, e.g. watermarks spread over several images
• CPC Class Codes: G06T 2201/0064 for copy protection or copy management, e.g. CGMS, copy only once, one-time copy
• CPC Class Codes: G06T 2201/0065 Extraction of an embedded watermark; Reliable detection
• CPC Class Codes: G06T 2201/0083 whereby only watermarked image required at decoder, e.g. source-based, blind, oblivious
• CPC Class Codes: G11B 19/122 involving the detection of an identification or authentication mark record carriers indicating unauthorised or prior use G11B23/28
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/00123 the record carrier being identified by recognising some of its unique characteristics, e.g. a unique defect pattern serving as a physical signature of the record carrier
• CPC Class Codes: G11B 20/00695 said measures preventing that data are read from the recording medium
• CPC Class Codes: G11B 20/00702 said measures preventing that data are recorded on the recording medium
• CPC Class Codes: G11B 20/00768 wherein copy control information is used, e.g. for indicating whether a content may be copied freely, no more, once, or never, by setting CGMS, SCMS, or CCI flags
• CPC Class Codes: G11B 20/00884 involving a watermark, i.e. a barely perceptible transformation of the original data which can nevertheless be recognised by an algorithm
• CPC Class Codes: G11B 2220/2562 DVDs [digital versatile discs]; Digital video discs; MMCDs; HDCDs
• CPC Class Codes: H04N 1/32144 embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
• CPC Class Codes: H04N 19/14 Coding unit complexity, e.g. amount of activity or edge presence estimation H04N19/146 takes precedence
• CPC Class Codes: H04N 19/467 characterised by the embedded information being invisible, e.g. watermarking
• CPC Class Codes: H04N 2201/3236 Details of authentication information generation

Abstract

This invention relates to a method of embedding a watermark pattern with a payload in a time dependent information signal, comprising the steps of determining a number of robust signatures in the information signal, creating the payload being dependent of at least one of the number of robust signatures and a predefined message, embedding the watermark pattern according to the payload in the information signal. The invention also relates to a corresponding method and arrangement for detecting a watermark pattern in an information signal.

Claims

1. A method of embedding a watermark pattern (W) with a payload (P) in a time dependent information signal (X), comprising the steps of:

determining a number of robust signatures (S), each signature (S) being a set of robust features in said information signal (X), said robust signatures being determined in a predetermined time interval of said information signal,

creating the payload (P) being dependent of at least one of said number of robust signatures (S) and a predefined message (M),

embedding said watermark pattern (W) according to said payload (P) in said information signal (X).

2. A method according to claim 1 wherein the payload (P) is created as a signature dependent, invertible function of said message (M).

3. A method according to claim 1 wherein the payload (P) is created by concatenating the message (M) and a function of at least one of said signatures (S).

4. A method according to claim 1, wherein the payload is dependent of at least one random signature from said number of robust signatures (S).

5. A method according to claim 1, wherein the payload is dependent of at least the n-th signature from said number of robust signatures (S).

6. A method according to claim 1, wherein the payload is dependent of at least the most robust signature from said number of robust signatures (S).

7. A method according to claim 1, wherein the payload is dependent of signature chosen from said number of robust signatures (S), the signature being chosen using a key-frame.

8. A method of detecting a message (M) in a time dependent information signal (Y) with an embedded watermark pattern (W), said method comprising the steps of:

detecting the watermark pattern (W) in said information signal (Y) and detecting the payload (P),

determining a number of robust signatures, each signature (S) being a set of robust features in said information signal (Y), said robust signatures being determined in a predetermined time interval of said information signal (Y),

decoding said message (M) from said payload (P) using at least one of said number of robust signatures.

9. A method according to claim 8 wherein the message (M) is decoded from the payload (P) using a signature dependent, invertible function of said payload (P).

10. A method according to claim 8 wherein payload (P) has been created by concatenating the message (M) and a function of at least one of said signatures (S) and wherein the step of decoding the payload (P) comprises means for selecting the relevant part of said payload (P)

11. A method according to claim 10 wherein the decoding of said message from said payload comprises the step of checking that the remaining part of the payload is a function of at least one of said signatures (S).

12. A method according to claim 8, wherein the decoding of said message (M) from said payload (P) is done using the n-th signature from said number of robust signatures (S).

13. A method according to claim 8, wherein the decoding of said message (M) from said payload (P) is done using the most robust signature from said number of robust signatures (S).

14. A method according to claim 8, wherein the decoding of said message (M) from said payload (P) is done by consecutively using all the signatures from said number of robust signatures (S).

15. An arrangement for embedding a watermark pattern (W) with a payload (P) in a time dependent information signal (X), comprising:

means for determining a number of robust signatures (S), each signature (S) being a set of robust features in said information signal (X), said robust signatures being determined in a predetermined time interval of said information signal,

means for creating the payload (P) being dependent of at least one of said number of robust signatures (S) and a predefined message (M),

means for embedding said watermark pattern (W) according to said payload (P) in said information signal (X).

16. An arrangement for detecting a message (M) in a time dependent information signal (Y) with an embedded watermark pattern (W), comprising:

means for detecting the watermark pattern (W) in said information signal (Y) and detecting the payload (P),

means for determining a number of robust signatures, each signature (S) being a set of robust features in said information signal (Y), said robust signatures being determined in a predetermined time interval of said information signal (Y),

means for decoding said message (M) from said payload (P) using at least one of said number of robust signatures.

17. A device for recording and/or playing back an information signal, the device comprising means (402) for disabling recording and/or playback of the information signal in dependence upon a watermark pattern (W) embedded in said information signal wherein the device further comprises an arrangement (404) for detecting said basic watermark pattern (V) according to claim 16.

18. A device for transmitting an information signal, the device comprising an arrangement for embedding a watermark pattern (W) with a payload (P) in a time dependent information signal (X), comprising:

means for determining a number of robust signatures (S), each signature (S) being a set of robust features in said information signal (X), said robust signatures being determined in a predetermined time interval of said information signal,

means for creating the payload (P) being dependent of at least one of said number of robust signatures (S) and a predefined message (M)

means for embedding said watermark pattern (W) according to said payload (P) in said information signal (X).

19. An information signal (Y) with an embedded watermark pattern (W) and a payload (P), said payload (P) being dependent of at least one of a number of robust signatures in said information signal (Y) and a predefined message (M).

20. An information signal (Q) according to claim 19, wherein the payload (P) is a signature dependent, invertible function of said message (M).

21. A storage medium (401) having stored thereon an information signal (Y) with an embedded watermark pattern (W) and a payload (P), said payload (P) being dependent of at least one of a number of robust signatures in said information signal (Y) and a predefined message (M).