Embedding hidden auxiliary code signals in media

• US 20050100188A1
• Filed: 04/01/2003
• Published: 05/12/2005
• Est. Priority Date: 11/18/1993
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Rhoads, Geoffrey B.
• Granted Patent: US 7,003,132 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• 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 1/005 Robust watermarking, e.g. average attack or collusion attack resistant
• CPC Class Codes: G06T 1/0057 Compression invariant watermarking
• CPC Class Codes: G06T 2201/0052 Embedding of the watermark in the frequency domain
• CPC Class Codes: G06T 2201/0065 Extraction of an embedded watermark; Reliable detection
• CPC Class Codes: G06T 2201/0081 whereby both original and watermarked images are required at decoder, e.g. destination-based, non-blind, non-oblivious
• CPC Class Codes: G07C 9/253 visually
• CPC Class Codes: G07D 7/0032 using holograms
• CPC Class Codes: G07D 7/004 using digital security elements, e.g. information coded on a magnetic thread or strip
• CPC Class Codes: G07F 17/16 for devices exhibiting advertisements, announcements, pictures or the like
• CPC Class Codes: G07F 17/26 for printing, stamping, franking, typing or teleprinting apparatus ticket printing or the like apparatus G07F17/42
• CPC Class Codes: G07F 7/08 by coded identity card or credit card or other personal identification means without personal verification means G07F7/02
• 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: G07F 7/1016 Devices or methods for securing the PIN and other transaction-data, e.g. by encryption arrangements for secret communication, see H04L9/00
• CPC Class Codes: G07F 7/12 Card verification
• 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 20/00094 involving measures which result in a restriction to authorised record carriers
• CPC Class Codes: G11B 20/00115 : wherein the record carrier stores a unique medium identifier
• CPC Class Codes: G11B 20/00166 : involving measures which result in a restriction to authorised contents recorded on or reproduced from a record carrier, e.g. music or software
• CPC Class Codes: G11B 20/00181 : using a content identifier, e.g. an international standard recording code [ISRC] or a digital object identifier [DOI]
• CPC Class Codes: G11B 20/0021 : involving encryption or decryption of contents recorded on or reproduced from a record carrier
• 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: H04B 1/665 : using psychoacoustic properties of the ear, e.g. masking effect
• 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 1/00838 : Preventing unauthorised reproduction
• CPC Class Codes: H04N 1/00846 : based on detection of a dedicated indication, e.g. marks or the like
• 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 1/32208 : 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 1/32251 : 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 2005/91321 : the copy protection signal being a copy protection control signal, e.g. a record inhibit signal
• CPC Class Codes: H04N 2005/91335 : the copy protection signal being a watermark
• 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 2201/3226 : of identification information or the like, e.g. ID code, index, title, part of an image, reduced-size image
• CPC Class Codes: H04N 2201/3233 : 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 2201/328 : Processing of the additional information
• CPC Class Codes: H04N 5/913 : for scrambling ; for copy protection

Abstract

Methods for embedding and reading auxiliary messages from image signals use embedded code signals modulated with the auxiliary message. These embedded ode signals may be used to convey hidden tracking codes in images, video and printed objects. The embedded code signals are embedded by varying characteristics of the image signal, including, for example, gray-level, reflective properties, photo-reactive properties, etc.

Claims

1. A method of hiding an auxiliary message signal in an image signal comprising:

receiving an auxiliary message signal comprising two or more message symbols;

associating the symbols with corresponding code signals comprising a plurality of elements, the plurality of elements having a mapping to corresponding locations in the image signal; and

adjusting the image signal at the corresponding locations according to a value of the message symbol, the code signal, and at least a characteristic of the image signal to produce an image signal with the auxiliary message hidden in the image signal.

2. The method of claim 1 wherein the image signal is adjusted by varying reflective properties of the image on a physical medium.

3. The method of claim 1 wherein the image signal is adjusted by varying photo-reactive properties of the image on a physical medium.

4. The method of claim 1 wherein the image signal comprises video.

5. The method of claim 1 wherein the mapping of the code signal has a random or pseudo-random property.

6. The method of claim 5 wherein the image signal comprises video and the locations correspond to spatial locations within the video.

7. The method of claim 6 wherein the adjusting comprises a non-linear adjustment according to a perceptibility function computed from an image characteristic.

8. A computer readable medium on which is stored instructions for performing the method of claim 1.

9-15. -15. (canceled)

16. A method of reading a hidden an auxiliary message signal embedded in an image signal, where the auxiliary message signal comprising two or more message symbols, the message symbol values modulating embedded code signals, the embedded code signals having a plurality of elements mapped to location in the image signal, the method comprising:

analyzing the image signal to determine an estimate of polarity of elements of the embedded code signals; and

extracting message symbol values from polarity of corresponding elements of the embedded code signals.

17. The method of claim 16 including using an original image without embedded data to register the image with embedded data, and subtracting the original image from the registered image with embedded data.

18. The method of claim 16 including evaluating the image signal to generate estimates of the polarity of the embedded code signal without using an original image not having the embedded data.

19. The method of claim 16 wherein the image signal comprises video and the auxiliary data includes an identification code to track different copies of the video.

20. A computer readable medium on which is stored instructions for performing the method of claim 16.

21. A method of hiding an auxiliary message signal in an image signal comprising:

receiving an auxiliary message signal comprising two or more message symbols;

associating the symbols with corresponding code signals comprising a plurality of elements, the plurality of elements having a mapping to corresponding locations in the image signal; and

at the corresponding locations, embedding the message symbols in the image signal according to a value of the message symbol and the code signal to produce an image signal with embedded auxiliary information, wherein the embedding is at least in part controlled as a function of a characteristic of the image signal to produce an image signal with the auxiliary message hidden in the image signal.

22. The method of claim 21 wherein the image signal comprises video.

23. The method of claim 21 wherein the value of the message symbol is used to set polarity of corresponding elements of the code signals for embedding into the image signal.

24. The method of claim 21 wherein the code signals are maintained below a perceptibility threshold.

25. The method of claim 24 wherein the code signals are created to have particular frequency characteristics.

26. The method of claim 21 wherein the code signals are created to have particular frequency characteristics.

27. The method of claim 21 wherein the embedding comprises a non-linear adjustment according to a function computed from an image characteristic.