Digital watermark and steganographic decoding

• US 7,369,678 B2
• Filed: 06/13/2006
• Issued: 05/06/2008
• Est. Priority Date: 05/08/1995
• Status: Expired due to Fees

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Rhoads, Geoffrey B.
• Primary Examiner(s): Couso; Jose L.
• Application Number:
  US11/452,662
• Publication Number:
  US 20060233420A1
• Time in Patent Office: 693 Days
• Field of Search: 382/100, 382/232, 382/236, 358/328, 380201-203, 380/210, 380/216, 380/231, 380/287, 348460-461, 348473-474, 370527-529
• US Class Current: 382/100
• CPC Class Codes: B42D 25/00 Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof printing processes to produce identification or security features B41M3/14
• CPC Class Codes: B42D 25/333 Watermarks
• CPC Class Codes: G06F 16/955 using information identifiers, e.g. uniform resource locators [URL]
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 19/06046 Constructional details
• CPC Class Codes: G06K 19/14 the marking being sensed by radiation
• CPC Class Codes: G06K 19/18 Constructional details
• CPC Class Codes: G06K 2019/06253 for a specific application
• CPC Class Codes: G06K 7/1417 2D bar codes
• CPC Class Codes: G06K 7/1447 extracting optical codes from image or text carrying said optical code
• CPC Class Codes: G06Q 20/1235 with control of digital rights management [DRM]
• CPC Class Codes: G06Q 20/341 Active cards, i.e. cards including their own processing means, e.g. including an IC or chip
• CPC Class Codes: G06Q 20/40145 Biometric identity checks
• 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 1/0064 Geometric transfor invariant watermarking, e.g. affine transform invariant
• CPC Class Codes: G06T 1/0071 using multiple or alternating watermarks
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0052 Embedding of the watermark in the frequency domain
• CPC Class Codes: G06T 2201/0061 Embedding of the watermark in each block of the image, e.g. segmented watermarking
• 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: G06V 30/40 : Document-oriented image-based pattern recognition
• CPC Class Codes: G07C 9/253 : visually
• CPC Class Codes: G07D 7/0034 : using watermarks
• CPC Class Codes: G07D 7/004 : using digital security elements, e.g. information coded on a magnetic thread or strip
• CPC Class Codes: G07F 7/086 : by passive credit-cards adapted therefor, e.g. constructive particularities to avoid counterfeiting, e.g. by inclusion of a physical or chemical security-layer for security documents G07D7/00; for the reading of record-carriers in general G06K7/00; for the design of coded credit-cards G06K19/10
• CPC Class Codes: G07F 7/1008 : Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system
• CPC Class Codes: G10L 19/018 : Audio watermarking, i.e. embedding inaudible data in the audio signal
• 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 20/00884 : 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 20/00891 : embedded in audio data
• CPC Class Codes: H04H 20/31 : using in-band signals, e.g. subsonic or cue signal
• CPC Class Codes: H04L 63/06 : for supporting key management in a packet data network cryptographic mechanisms or cryptographic arrangements for key management H04L9/08
• CPC Class Codes: H04N 1/00005 : relating to image data
• CPC Class Codes: H04N 1/00037 : Detecting, i.e. determining the occurrence of a predetermined state H04N1/00031 takes precedence
• CPC Class Codes: H04N 1/00079 : remotely
• CPC Class Codes: H04N 1/32122 : in a separate device, e.g. in a memory or on a display separate from image data
• 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 1/32149 : Methods relating to embedding, encoding, decoding, detection or retrieval operations
• CPC Class Codes: H04N 1/32154 : Transform domain methods H04N1/32309 takes precedence
• CPC Class Codes: H04N 1/3216 : using Fourier transforms
• CPC Class Codes: H04N 1/32187 : with selective or adaptive application of the additional information, e.g. in selected frequency coefficients
• CPC Class Codes: H04N 1/32203 : Spatial or amplitude domain methods H04N1/32309 takes precedence
• CPC Class Codes: H04N 1/32208 : involving changing the magnitude of selected pixels, e.g. overlay of information or super-imposition H04N1/32219, H04N1/32224 take precedence
• CPC Class Codes: H04N 1/32229 : with selective or adaptive application of the additional information, e.g. in selected regions of the image H04N1/32213 takes precedence
• CPC Class Codes: H04N 1/32251 : in multilevel data, e.g. greyscale or continuous tone data
• CPC Class Codes: H04N 1/32288 : Multiple embedding, e.g. cocktail embedding, or redundant embedding, e.g. repeating the additional information at a plurality of locations in the image
• CPC Class Codes: H04N 1/32352 : Controlling detectability or arrangements to facilitate detection or retrieval of the embedded information, e.g. using markers for decoding, detection or retrieval operations H04N1/32149 and subgroups take precedence
• CPC Class Codes: H04N 19/467 : characterised by the embedded information being invisible, e.g. watermarking
• CPC Class Codes: H04N 19/645 : by grouping of coefficients into blocks after the transform
• CPC Class Codes: H04N 21/23892 : involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level
• CPC Class Codes: H04N 21/44008 : involving operations for analysing video streams, e.g. detecting features or characteristics in the video stream arrangements characterised by components specially adapted for monitoring, identification or recognition of video in broadcast systems H04H60/59
• CPC Class Codes: H04N 21/4627 : Rights management associated to the content security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• CPC Class Codes: H04N 21/8358 : involving watermark protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467
• CPC Class Codes: H04N 2201/3205 : of identification information, e.g. name or ID code H04N2201/3209 takes precedence
• CPC Class Codes: H04N 2201/3207 : of an address
• CPC Class Codes: H04N 2201/3225 : of data relating to an image, a page or a document
• CPC Class Codes: H04N 2201/3226 : of identification information or the like, e.g. ID code, index, title, part of an image, reduced-size image
• CPC Class Codes: H04N 2201/323 : for tracing or tracking, e.g. forensic tracing of unauthorized copies
• CPC Class Codes: H04N 2201/3233 : of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/327 : which are undetectable to the naked eye, e.g. embedded codes
• CPC Class Codes: H04N 2201/3271 : Printing or stamping
• CPC Class Codes: H04N 2201/3274 : Storage or retrieval of prestored additional information
• CPC Class Codes: H04N 2201/328 : Processing of the additional information
• CPC Class Codes: H04N 2201/3284 : for error correction
• CPC Class Codes: H04N 7/163 : by receiver means only

Abstract

Steganographic signals or digital watermarks are detected from media signals. A media signal may represent audio, video or imagery. In one implementation, a method of detecting a digital watermark in a media signal is provided. The method includes receiving blocks of the media signal; buffering the blocks; screening the blocks for a presence of the digital watermark to identify a plurality of blocks likely to include the digital watermark based on a detection metric; combining the blocks that have been identified as being likely to include the digital watermark; and detecting the watermark from the combined blocks. Other implementations are provided as well.

Claims

1. A watermark decoding method comprising:

receiving a media signal encoded with a multi-bit message, the media signal comprising a plurality of portions;

synchronizing at least one portion of the media signal based at least in part on a component steganographically hidden therein;

analyzing a first portion of a media signal to estimate a first instance of a multi-bit message steganographically hidden therein;

analyzing at least a second portion of the media signal to estimate a second instance of the multi-bit message steganographically hidden therein;

combining the estimate of the first instance of the plural-bit message and the estimate of the second instance of the multi-bit message; and

decoding the multi-bit message from the combined estimates.

2. The method of claim 1 further comprising analyzing at least a third portion of the media signal to estimate a third instance of the multi-bit message steganographically hidden therein, wherein said act of combining includes combining the estimate of the third portion with the estimate of the first instance and the estimate of the second instance.

3. The method of claim 1 wherein the first portion and the second portion represent the media signal at different times.

4. The method of claim 1 wherein the media signal comprises at least one of audio or video.

5. The method of claim 1 wherein a representation of the plural-bit message varies from the first portion to the second portion.

6. The method of claim 5 wherein the representation varies according to a predetermined pattern.

7. The method of claim 1 further comprising transforming the first portion and the second portion.

8. A method of detecting a digital watermark in a digitally watermarked media signal, the method comprising:

receiving blocks of the digitally watermarked media signal;

buffering the blocks;

screening the blocks for a presence of the digital watermark to identify a plurality of blocks likely to include the digital watermark based on a detection metric;

combining the blocks that have been identified as being likely to include the digital watermark; and

detecting the watermark from the combined blocks.

9. The method of claim 8 further comprising transforming media signal data in the blocks prior to combining the blocks.

10. The method of claim 9 wherein the transforming includes adjusting the position of media signal data.

11. The method of claim 9 wherein the transforming includes adjusting a temporal position of the media signal data.

12. The method of claim 8 wherein the blocks comprise portions of the media signal at different times.

13. The method of claim 12 wherein the blocks originate from different frames of video.

14. The method of claim 13 wherein the different frames of video are captured by a camera imaging a digitally watermarked object.

15. A method of detecting a digital watermark in a digitally watermarked media signal, the method comprising:

receiving blocks of the digitally watermarked media signal;

computing a detection metric for the blocks;

ranking the blocks based on the detection metric; and

using the ranking to prioritize detection of the digital watermark from the blocks.

16. The method of claim 15 further comprising transforming the blocks prior to said act of computing.

17. The method of claim 16 wherein the transforming includes adjusting a position of the media signal.

18. The method of claim 16 wherein the transforming includes adjusting a temporal position of the media signal data.

19. The method of claim 18 wherein the blocks comprise portions of the media signal at different times.

20. The method of claim 19 wherein the blocks originate from different frames of video.

21. The method of claim 15 wherein the detection metric is a function of coincidence of detection parameters of different blocks.

22. The method of claim 15 wherein the detection metric comprises watermark synchronization information.

23. A method of detecting a digital watermark in a digitally watermarked media signal, the digital watermark comprises a multi-bit auxiliary data signal, the method comprising:

receiving blocks of the digitally watermarked media signal;

extracting estimates of the multi-bit auxiliary data signal from the blocks;

combining the estimates of the multi-bit auxiliary data from the blocks; and

decoding a multi-bit auxiliary data signal from the combined estimates.

24. The method of claim 23 wherein the blocks represent different temporal portions of the media signal.