Image steganography system featuring perceptually adaptive and globally scalable signal embedding

• US 5,748,763 A
• Filed: 05/08/1995
• Issued: 05/05/1998
• Est. Priority Date: 11/18/1993
• Status: Expired due to Term

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Rhoads, Geoffrey B.
• Primary Examiner(s): Boudreau, Leo
• Assistant Examiner(s): KELLEY, CHRISTOPHER S
• Application Number:
  US08/436,134
• Time in Patent Office: 1,093 Days
• Field of Search: 382/115, 382/232, 382/276, 348/460, 380/3, 380/4, 380/5, 380/54, 340/825.34, 364/715.01, 364/715.02, 283/70, 341/120
• US Class Current: 382/115
• CPC Class Codes: G06F 12/1408 by using cryptography for digital transmission H04L9/00
• 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 1/005 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: 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 20/00007 Time or data compression or expansion audio compression based on psychoacoustics G10L19/00; data processing for reproducing audio data at different playback speeds G10L21/04; video compression H04N19/00; data compression per se H03M7/30
• 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: G11B 20/10037 : A/D conversion, D/A conversion, sampling, slicing and digital quantisation or adjusting parameters thereof
• CPC Class Codes: G11B 20/10527 : Audio or video recording; Data buffering arrangements G11B20/12 - G11B20/18 take precedence
• CPC Class Codes: G11B 2020/00014 : the compressed signal being an audio signal
• CPC Class Codes: G11B 2020/10546 : specifically adapted for audio data
• CPC Class Codes: G11B 2020/10555 : wherein the frequency, the amplitude, or other characteristics of the audio signal is taken into account
• 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 1/32144 : 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 1/32203 : 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 1/32251 : 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 2005/91342 : the copy protection signal being an authentication signal
• CPC Class Codes: H04N 2005/9135 : by superimposing the spectrally spread copy protection signal onto the video signal
• 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 5/89 : using holographic recording H04N5/91 takes precedence
• CPC Class Codes: H04N 5/90 : on discs or drums
• CPC Class Codes: H04N 5/913 : for scrambling ; for copy protection
• CPC Class Codes: H04N 9/8042 : involving data reduction
• CPC Class Codes: H04N 9/8047 : using transform coding
• CPC Class Codes: H04N 9/8205 : involving the multiplexing of an additional signal and the colour video signal
• CPC Class Codes: Y10S 283/901 : Concealed data

Abstract

An identification code signal is hidden in a carrier signal (such as an electronic data signal or a physical medium) in a manner that permits the identification signal later to be discerned. The carrier signal can thereby be identified, or some machine responsive action can thereby be taken. In one image steganography embodiment, the relative strength of the identification code signal is both perceptually adapted in accordance with psychovisual characteristics of the image, and globally scaled in accordance with a user-set visibility control. The technique can be applied in video imagery embodiments to control associated video equipment, e.g. to serve as a copy control signal.

Claims

1. A method of processing input image data to steganographically encode a multi-bit identification code therein, thereby producing output image data, characterized by:

defining a global scaling parameter;

algorithmically determining, from the input image data, a first parameter for each of a first plurality of portions of the image data, said first parameter relating to the relative capability of said portion to conceal encoding thereof by the identification code;

encoding the identification code through a second plurality of portions of the image data to produce the output image data, said second plurality being a subset of the first plurality, the code in each of said second plurality of portions being encoded in accordance with both the first parameter corresponding to said each portion, and said global scaling parameter;

wherein the relative strength of the identification code through different portions of the output image changes both in accordance with characteristics of the input image, and globally in accordance with a global scale factor.

2. The method of claim 1 which includes computing a second parameter for each of said first plurality of portions, and computing the first parameter from the second parameter by a non-linear function.

3. The method of claim 1 in which each first parameter is related to a corresponding second parameter by a square root relationship.

4. The method of claim 1 in which the defminig step includes displaying a graphical user interface, said interface including a feature permitting a user to assign a value to the global scaling parameter, wherein the relative strength of the identification code through different portions of the output image changes in accordance with characteristics of the input image, and globally in accordance with a global scale factor set by the user through the user interface.

5. The method of claim 1 which includes processing a video signal in real time to steganographically encode the identification code therein.

6. The method of claim 1 in which the encoding includes processing in accordance with pseudo-random noise data.

7. The method of claim 1 in which the encoding includes encoding the input image in a sampled image domain, without a transformation to a frequency domain.

8. The method of claim 1 in which the second plurality of portions includes all of the first plurality of portions.

9. The method of claim 1 in which the second plurality of portions does not include all of the first plurality of portions.

10. The method of claim 9 wherein there are certain portions of the output image that have no part of the identification code encoded therein.

11. The method of claim 1 in which the encoding includes processing in accordance with a non-pseudo random first signal.

12. The method of claim 1 in which each of said portions comprises a single pixel.

13. The method of claim 1 in which each of said portions comprises a plurality of pixels.

14. A machine readable storage medium having an output image, produced in accordance with the process of claim 1 stored therein.

28. The method of claim 1 in which the encoding step includes encoding a single bit of said multi-bit identification code in each portion of said second plurality of portions of image data.

15. A method of steganographically embedding multi-bit auxiliary data into an input motion picture signal that is thereafter compressed to yield a compressed signal, said embedding being both locally adapted based on image contents and globally adjustable, and thereafter discerning the multi-bit auxiliary data from a non-identical counterpart to said motion picture signal obtained by decompressing the compressed signal, the method comprising encoding and decoding processes characterized in that:

(A) the encoding process includes;

(1) providing an input motion picture signal comprising a plurality of frames of image data, each frame comprising a plurality of pixels, each pixel having a value associated therewith;

(2) providing a control by which a user can set the relative value of a global scaling parameter, said parameter determing a relative intensity at which the multi-bit auxiliary data will be embedded into the motion picture signal;

(3) for each of a plurality of portions in a frame of image data, algorithmically determining a first parameter corresponding thereto, said first parameter relating to the relative capability of said portin to conceal encoding thereof by the auxiliary data;

(4) for each of a plurality of pixels in said frame, transforming the value thereof in accordance with;

(a) a first parameter corresponding thereto,

(b) the global scaling parameter, and

(c) at least some of said multi-bit auxiliary data, wherein an encoded frame of image data is produced having the auxiliary data embedded therein, said embedding being both globally scaled, and locally adapted based on image contents;

(5) repeating steps (3) and (4) for a plurality of different frames of said motion picture signal, thereby yielding a first encoded motion picture signal; and

(6) compressing the first encoded motion picture signal;

(B) the decoding process includes;

(1) decompressing the compressed, first encoded motion picture signal to produce a second encoded motion picture signal, said second encoded motion picture signal being non-identical to the first encoded motion picture signal due to said compression/decompression process;

(2) discerning the multi-bit auxiliary data from the second encoded motion picture signal without reference to the input motion picture signal.

16. The method of claim 15 in which the discerning step includes processing a plurality of frames of said second encoded motion picture signal to determine the auxiliary multi-bit data encoded therein, wherein greater or lesser confidence in the auxiliary multi-bit data discerned from said second encoded motion picture signal can be obtained by processing more or less frames, respectively.

17. The method of claim 16 which includes performing said processing by a hardware decoding circuit.

18. The method of claim 17 which includes disabling recording capability of an apparatus based on said discerned auxiliary multi-bit data.

19. The method of claim 17 which includes incrementing a program specific billing meter based on said discerned auxiliary multi-bit data.

20. The method of claim 15 which includes:

after step (A)(6), storing said compressed, first encoded motion picture data on an optically encoded storage disk; and

prior to step (B)(1), reading said compressed, first encoded motion picture data from said optically encoded storage disk.

21. The method of claim 15 which includes converting the second encoded motion picture data to analog form, and thereafter discerning the multi-bit auxiliary data therefrom.

22. The method of claim 21 which includes digitizing the analog form of the second encoded motion picture data to produce a digitized signal, and discerning the multi-bit auxiliary data from said digitized signal.

23. The method of claim 15 in which all of said steps occur in the spatial image domain, rather than some occurring in a transformed, frequency domain.

24. The method of claim 15 in which said providing a control step includes displaying a graphical user interface, said interface including a feature permitting the user to assign a value to the global scaling parameter, wherein the relative strength of the multi-bit auxiliary data through different portion of the second encoded motion picture data changes locally in accordance with characteristics of the frame of image data, and globally in accordance with the global scale factor set by the user through the user interface.

25. The method of claim 15 in which step (A)(4) additionally includes processing the value of said plurality of pixels in accordance with samples of a pseudo-random noise signal.

26. The method of claim 15 in which each of said portions comprises a single pixel.

27. The method of claim 15 in which each of said portions comprises a plurality of pixels.