Data hiding method and system for embedding and extracting information in signals

• US 7,054,465 B2
• Filed: 10/16/2002
• Issued: 05/30/2006
• Est. Priority Date: 11/18/1993
• 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:
  US10/273,311
• Publication Number:
  US 20030142847A1
• Time in Patent Office: 1,322 Days
• Field of Search: 382/100, 382/232, 358/3.28, 380/201, 380/202, 380/203, 380/210, 380/216, 380/231, 380/287, 348/460, 348/461, 348/473, 348/474, 370/527, 370/528, 370/529
• 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: 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 1/0021 Image 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 2201/0052 Embedding of the watermark in the frequency domain
• CPC Class Codes: G06V 30/40 Document-oriented image-based pattern recognition
• CPC Class Codes: G07C 9/253 visually
• CPC Class Codes: G07D 7/0032 using holograms
• 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 17/0014 : for vending, access and use of specific services not covered anywhere else in G07F17/00 meter-controlled dispensing of liquid, gas or electricity G07F15/00
• 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 20/00231 : wherein the key is obtained from a local external medium, e.g. a card
• CPC Class Codes: G11B 20/0071 : involving a purchase action
• 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: H04L 2463/103 : applying security measure for protecting copy right protecting software against unauthorised usage in a vending or licensing environment, e.g. protection the software providers copyright G06F21/10; data processing systems or methods, specially adapted for payment schemes, architectures or protocols G06Q20/00; secrecy systems or subscription systems H04N7/16
• 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 1/3216 : using Fourier transforms
• 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 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 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 21/23892 : involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level
• 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 2201/3233 : 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 5/913 : for scrambling ; for copy protection
• CPC Class Codes: H04W 24/00 : Supervisory, monitoring or testing arrangements

Abstract

A data hiding method embeds information into an input signal. The method prepares a code signal having a plurality of elements with positive and negative values, and specifies blocks in the input signal into which the information is to be embedded. It determines an amount to modify elements of the input signal based on the values of the code signal and an encoding method that specifies how the code signal is to be applied to the block based on meaning of information to be embedded. It then adds this amount of modification. The process is repeated for additional blocks. The process of extracting the embedded information includes correlating the code signal with the block with respect to each block and obtaining a statistical value from the block values, and extracting embedded information according to the statistical value by referring to a decoding method, which provides a correspondence between the statistical value and meaning of information to be extracted.

Claims

1. A data hiding method for embedding information into an input signal, said input signal comprising a plurality of elements, said method comprising:

(a) preparing a code signal having a plurality of elements, said code signal having positive and negative values;

(b) specifying blocks in said input signal into which blocks certain information is embedded, said blocks having a size corresponding to that of corresponding parts of said code signal;

(c) determining an amount to modify elements of the input signal based on the values of the code signal corresponding to a block and an encoding method that specifies how the code signal is to be applied to the block based on meaning of information to be embedded;

d) adding the determined amount to the input signal at the block; and

(e) performing the steps (c) to (d) with respect to the blocks so that information is embedded in the blocks.

2. The method of claim 1 wherein the encoding method specifies the polarity of the code signal.

3. A method for extracting embedded information from an input signal comprising a plurality of elements, the method comprising:

(a) specifying blocks in which information is embedded in said input signal, said blocks having a size corresponding to that of a corresponding code signal, the code signal having a plurality of elements, and having positive and negative values;

(b) calculating a block value by correlating said code signal with said block with respect to each block and obtaining a statistical value from the block values; and

(c) extracting embedded information according to the statistical value by referring to a decoding method providing a correspondence between the statistical value and meaning of information which should be extracted.

4. The method of claim 3 wherein the decoding method specifies that a sign of the statistical value conveys meaning of the embedded information.

5. A data hiding system for embedding information in an input signal comprising a plurality of elements, the system comprising:

(a) a unit for preparing a code signal having a plurality of elements, said code signal having at least positive and negative values;

(b) a unit for specifying blocks in said input signal into which blocks certain information is embedded, said blocks having a size corresponding to that of corresponding parts of said code signal;

(c) a unit for determining an amount to modify elements of the input signal based on the values of the code signal corresponding to a block and an encoding method that specifies how the code signal is to be applied to the block based on meaning of information to be embedded;

(d) a unit for adding the determined amount to the input signal at the block; and

(e) a unit for operating the units (c) to (d) with respect to the blocks so that information is embedded in the blocks.

6. The system of claim 5 wherein the encoding method specifies the polarity of the code signal.

7. A system for extracting embedded information from an input signal comprising a plurality of elements, the system comprising:

(a) a unit for specifying blocks in which information is embedded in said input signal, said blocks having a size corresponding to that of a corresponding code signal, the code signal having a plurality of elements, and having positive and negative values;

(b) a unit for calculating a block value by correlating said code signal with said block with respect to each block and obtaining a statistical value from the block values; and

(c) a unit for extracting embedded information according to the statistical value by referring to a decoding method providing a correspondence between the statistical value and meaning of information which should be extracted.

8. The system of claim 7 wherein the decoding method specifies that a sign of the statistical value conveys meaning of the embedded information.

9. A system for embedding information into data, the information controlling use of said data, said data comprising a plurality of elements, the system comprising:

(a) a unit for preparing the control information to be embedded;

(b) a unit for preparing a code signal having a plurality of elements, said code signal having positive and negative values;

(c) a unit for specifying blocks of the data elements into which blocks said control information is embedded, said blocks having a size corresponding to that of corresponding parts of said code signal;

(d) a unit for determining an amount to modify elements of the data based on the values of the code signal corresponding to a block and an encoding method that specifies how the code signal is to be applied to the block based on meaning of information to be embedded;

(e) a unit for adding the determined amount to the data at the block; and

(f) a unit for operating the units (c) to (d) with respect to this blocks so that information is embedded into the blocks.

10. The system of claim 9 wherein the encoding method specifies the plurality of the code signal.

11. A system for extracting embedded control information from an input signal, and controlling use of said input signal, said input signal comprising a plurality of elements, the system comprising:

(a) a unit for specifying blocks in which information is embedded in said input signal, said blocks having a size corresponding to that of a corresponding code signal, the code signal having a plurality of elements, and having positive and negative values;

(b) a unit for calculating a block value by correlating said code signal with said block with respect to each block and obtaining a statistical value from the block values;

(c) a unit for extracting embedded information according to the statistical value by referring to a decoding method providing a correspondence between the statistical value and meaning of information which should be extracted; and

(d) a unit for controlling use of said input signal according to the extracted control information.

12. The system of claim 11 wherein the decoding method specifies that a sign of the statistical value conveys meaning of the embedded information.

13. A method for extracting embedded information from an input signal comprising a plurality of elements, the method comprising:

(a) specifying blocks in which information is embedded in said input signal, said blocks having a size corresponding to that of corresponding parts of a code signal, the code signal having a plurality of elements, and having positive and negative values;

(b) calculating a block value by multiplying said code signal and a corresponding block of the input signal to compute a product and summing the product with respect to each of said blocks, and obtaining a statistical value from the sum of block values; and

(c) extracting embedded information according to the statistical value by referring to a decoding method providing a correspondence between the statistical value and meaning of information which should be extracted.

14. The method of claim 13 wherein the multiplying and summing comprise a dot product, correlation or matched filter operation.

15. A system for extracting embedded information from an input signal comprising a plurality of elements, the system comprising:

(a) a unit for specifying blocks in which information is embedded in said input signal, said blocks having a size corresponding to that of corresponding parts of a code signal, the code signal having a plurality of elements, and having positive and negative values;

(b) a unit for calculating a block value by multiplying said code signal and a corresponding block of the input signal to compute a product and summing the product with respect to each of said blocks, and obtaining a statistical value from the sum of block values; and

(c) a unit for extracting embedded information according to the statistical value by referring to a decoding method providing a correspondence between the statistical value and meaning of information which should be extracted.

16. The system of claim 15 wherein the multiplying and summing comprise a dot product, correlation or matched filter operation.

17. A system for extracting embedded control information from data, and controlling access to said data, said data comprising a plurality of elements, the system comprising;

(a) a unit for specifying blocks in which information is embedded in said data, said blocks having a size corresponding to that of a corresponding code signal, the code signal having a plurality of elements, and having positive and negative values;

(b) a unit for calculating a block value by multiplying said code signal and a corresponding block of the data to compute a product and summing the product with respect to each of said blocks, and obtaining a statistical value from the sum of block values;

(c) a unit for extracting embedded control information according to the statistical value by referring to a decoding method providing a correspondence between the statistical value and meaning of control information which should be extracted; and

(d) a unit for controlling access to said data according to the extracted control information.

18. The system of claim 17 wherein the multiplying and summing comprise a dot product, correlation or matched filter operation.