Audio watermarking to convey auxiliary information, and media employing same

• US 20040015363A1
• Filed: 03/25/2003
• Published: 01/22/2004
• Est. Priority Date: 11/18/1993
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Rhoads, Geoffrey B.
• Granted Patent: US 7,181,022 B2
• Time in Patent Office: Days
• US Class Current: 704/273
• 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

Methods of processing audio to convey auxiliary information therein without audible evidence of data alteration. Various arrangements are disclosed. One receives plural bit auxiliary data in which the auxiliary information is included, and modulates a carrier signal with the auxiliary data to yield intermediate data. The intermediate data is then summed with the original audio to produce the encoded audio. The carrier signal can be tailored to enhance performance, and the intermediate data can be scaled in amplitude so as to better hide the auxiliary data within the audio. One application of the technology is in monitoring, where the auxiliary information can be used to track usage of audio or audio-visual content.

Claims

1. A method of processing audio to convey auxiliary information therewith, the audio being represented by primary data, the auxiliary control information being included with plural-bit auxiliary data, the method comprising:

receiving the plural bit auxiliary data; and

encoding the plural-bit auxiliary data into the primary data without audible evidence of data alteration;

wherein the encoding includes;

for a bit of the auxiliary data, adding a scaled carrier signal corresponding to the bit to adjust a characteristic of a group of corresponding audio samples in the audio data so that the scaled carrier signal corresponds to a symbol value of the bit; and

repeating the adding of a scaled signal corresponding to bits in the auxiliary data to form a sequence of groups of audio carrying the plural bit auxiliary data, wherein the plural auxiliary data includes fixed auxiliary data distributed over the sequence of groups for detection and registration of the auxiliary data in the audio.

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

3. A method of processing audio to convey auxiliary information therewith without audible evidence of audio alteration, the audio being represented by digital data, the auxiliary information comprising a data string having plural bit positions, each with a “

1”

or “

0”

value, characterized in that the method comprises;

receiving the plural bit auxiliary data;

providing carrier data;

processing the plural bit auxiliary data and the carrier data to yield intermediate data; and

summing the intermediate data with the audio data to yield encoded audio;

wherein the audio is repeatedly encoded with the plural-bit auxiliary data so that the auxiliary data can be fully decoded from each of plural non-overlapping excerpts of the encoded audio; and

wherein instances of the auxiliary data include fixed data that is distributed over the audio conveying the instance for detection and registration of the auxiliary data in the audio.

4. The method of claim 3 wherein the carrier data is used to generate first noise data and further including transforming first noise data into quasi-noise data having properties better suited to hiding the auxiliary data within the audio data.

5. The method of claim 3 which includes scaling the amplitude of the intermediate data by a scaling factor prior to summing with the audio data.

6. The method of claim 5 in which the scaling factor changes in accordance with the audio, including a uniform gain across the audio carrying an instance of auxiliary data and a local gain that varies within the audio carrying the instance of auxiliary data.

7. A computer readable medium on which is stored instructions for performing the method of claim 3.

8. A method of processing audio to convey auxiliary information therewith without audible evidence of audio alteration, the audio being represented by digital data, the auxiliary information comprising a data string having plural bit positions, each with a “

1”

or “

0”

value, characterized in that the method comprises;

receiving the plural bit auxiliary data;

providing carrier data;

processing the plural bit auxiliary data and the carrier data to yield intermediate data; and

summing the intermediate data with the audio data to yield encoded audio, including scaling the amplitude of the intermediate data by a scaling factor prior to summing with the audio data, wherein the scaling factor changes in accordance with the audio, including a uniform amplitude control across the audio carrying an instance of auxiliary data and a local gain that varies within the audio carrying the instance of auxiliary data;

wherein the audio is repeatedly encoded with the plural-bit auxiliary data so that the auxiliary data can be fully decoded from each of plural non-overlapping excerpts of the encoded audio.

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

10. A method of embedding auxiliary information in audio data, the method comprising:

modifying the audio data, including, for a sequence of bits of the auxiliary information, generating an intermediate signal based on a carrier signal and corresponding to the sequence of bits, and using the intermediate signal to adjust a group of corresponding audio samples in the audio data, the sequence including a fixed set of bits distributed over the group of audio samples for registration of the auxiliary information; and

repeating the modifying of the audio data using an intermediate signal corresponding to bits in the auxiliary data.

11. The method of claim 10 in which the embedding has been effected by generating data independent of the audio data for the carrier signal and summing the intermediate signal with input audio information.

12. The method of claim 10 in which the independent data is shifted according to values of the sequence of bits prior to said summing.

13. A computer readable medium on which is stored instructions for performing the method of claim 10.

14. Apparatus for processing audio to convey auxiliary information therewith, the audio being represented by primary data, the auxiliary information being included with plural-bit auxiliary data, the apparatus comprising:

an auxiliary data source;

a carrier signal data source;

a steganographic code signal generator operable to receive auxiliary data symbols from the auxiliary data source and a carrier signal from the carrier signal data source and generating a modulated carrier; and

a combiner for combining the modulated carrier signal with segments of the audio, wherein instances of the auxiliary information are repeated in the segments of audio and each segment includes fixed data symbols distributed over the segment for registration;

wherein the plural-bit auxiliary data is encoded into the primary data without audible evidence of data alteration.

15. The apparatus of claim 14 in which at least certain of said carrier signal data source, steganographic code signal generator, and combiner, are implemented using a processor programmed in accordance with stored instructions.

16. A method of processing audio to convey auxiliary information therewith without audible evidence of audio alteration, the audio being represented by digital data, the auxiliary information comprising a data string having plural bit positions, each with a “

1”

or “

0”

value, characterized in that the method comprises;

receiving the plural bit auxiliary data;

providing carrier data;

processing the plural bit auxiliary data and the carrier data to yield intermediate data; and

summing the intermediate data with the audio data to yield encoded audio;

wherein the audio is repeatedly encoded with the plural-bit auxiliary data so that the auxiliary data can be fully decoded from each of plural non-overlapping excerpts of the encoded audio and wherein the processing includes selectively shifting the carrier data in accordance with the value of bits in the auxiliary data.

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

18. A method of processing audio to extract auxiliary information that has been embedded in the audio, the method comprising:

receiving audio embedded with plural-bit auxiliary information carried in a scaled carrier signal, repeated instances of the plural-bit auxiliary data being embedded in corresponding segments of the audio, wherein an instance comprises a sequence of auxiliary data symbols, and symbols in the sequence are carried in corresponding groups of audio samples in a segment, and wherein the plural-bit auxiliary data includes a fixed auxiliary data distributed over the segment for detection and registration of the auxiliary data in the audio;

decoding the plural-bit auxiliary data from the audio, including extracting the fixed auxiliary data from groups of samples in the segments to detect and register the plural-bit data auxiliary data in the segments, and extracting additional symbols of the plural bit auxiliary data from the segments.

19. The method of claim 18 wherein the scaled carrier signal is has a uniform amplitude control for a segment and a local gain for varying the amplitude of the scaled carrier signal within the segment.

20. A computer readable medium on which is stored instructions for performing the method of claim 18.