# US 6,157,330 A · Embedding supplemental data in an encoded signal, such as audio / video watermarks > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,157,330 A - Document ID: US6157330A - Status: Granted - Kind: A - Application number: 09/013,540 - Filed: 1998-01-26 - Granted: 2000-12-05 - Earliest claimed: 1997-01-27 - Assignees: U.S. Philips Corporation - Inventors: Alphons A. M. L. Bruekers; Geert F. G. Depovere; Petrus A. C. M. Nuijten; Arnoldus W. J. Oomen - Web page: https://patentgrep.com/patent/US6157330A ## CPC - G06T 1/0035: {Output size adaptive watermarking} - 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)} - G11B 20/00891: {embedded in audio data} - H04N 19/00: Methods or arrangements for coding, decoding, compressing or decompressing digital video signals - H04N 21/23892: {involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level} - 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)} - G11B 2020/00065: {Sigma-delta audio encoding} - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Method of embedding watermarks in a signal encoded by an encoder having a feedback loop, for example, a sigma-delta modulator (21,22,23). A digital watermark pattern (w) is embedded in the signal (z) by modifying selected samples (for example, replacing every 100th bit) of the encoded signal (y) by samples of the watermark pattern. The circuit (24) for modifying the samples is located inside the loop of the encoder. The effect of watermarking is thus compensated in subsequent encoding steps and the signal-to-noise ratio is only slightly affected. ## Claims ### Claim 1 A method of embedding supplemental data in an encoded signal, comprising the steps of: combining an input signal with a modified signal to produce a combined signal; encoding the combined signal in accordance with a given encoding process to produce an encoded signal; and modifying the encoded signal to represent the supplemental data to produce the modified signal. ### Claim 2 (depends on 1) The method of claim 1, wherein the encoding includes unity bit encoding. ### Claim 3 (depends on 2) The method of claim 2, wherein the encoding includes sigma-delta modulation. ### Claim 4 (depends on 1) The method of claim 1, wherein the step of modifying the encoded signal includes the replacement of selected samples of the encoded signal by samples of the supplemental data. ### Claim 5 (depends on 2) The method of claim 2, wherein the step of modifying the encoded signal includes the inversion of selected samples of the unity bit encoded signal, the embedded data being represented by the number of sample periods between successive inverted samples. ### Claim 6 A method of extracting supplemental data from a received encoded signal in which selected predetermined samples are replaced by samples of the supplemental data, and including the step of selecting the samples in response to a predetermined selection signal. ### Claim 7 (depends on 6) The method of claim 6, wherein the selection signal is retrieved by detecting a synchronization pattern included in the supplemental data. ### Claim 8 A method of extracting supplemental data from a received encoded signal, comprising the steps of: encoding the original signal in accordance with a given encoding process including the step of feeding back the received encoded signal to control the encoding; and comparing the encoded original signal and the received encoded signal, the difference between the signals representing the supplemental data. ### Claim 9 (depends on 8) The method of claim 8, wherein the supplemental data is represented by the number of sample periods between successive inverted samples, and further comprising the step of counting the number of sample periods between inverted samples to extract the supplemental data. ### Claim 10 An arrangement for embedding supplemental data in an encoded signal, comprising: means for combining an input signal with a modified signal to produce a combined signal; an encoder for encoding the combined signal to produce an encoded signal; means for modifying selected samples of the encoded signal to represent the supplemental data to produce the modified signal; and a feedback loop connected to feed the modified encoded signal back to the combining means. ### Claim 11 (depends on 10) The arrangement of claim 10, wherein the encoder includes a unity bit encoder. ### Claim 12 (depends on 11) The arrangement of claim 11, wherein the encoder includes a sigma-delta modulator. ### Claim 13 (depends on 10) The arrangement of claim 10, wherein the means for modifying the encoded signal includes a multiplexer for replacing selected samples of the encoded signal by samples of the supplemental data. ### Claim 14 (depends on 11) The method of claim 11, wherein the means for modifying the encoded signal include an inverter for inverting selected samples of the unity bit encoded signal, the embedded data being represented by the number of sample periods between successive inverted samples. ### Claim 15 An arrangement for extracting supplemental data from a received encoded signal in which selected predetermined samples are replaced by samples of the supplemental data, comprising: register means for selecting the samples in response to a predetermined selection signal. ### Claim 16 (depends on 15) The arrangement of claim 15, further comprising means for detecting a synchronization pattern included in the supplemental data and means for generating the selection signal in response to the detection. ### Claim 17 An arrangement for extracting supplemental data from a received encoded signal, comprising: encoder means for encoding the original signal without the supplemental data and using the received encoded signal containing the supplemental data to control the encoding; and means for comparing the encoded original signal with the received encoded signal, the difference between the signals representing the supplemental data. ### Claim 18 (depends on 17) The arrangement of claim 17, wherein the supplemental data is represented by the number of sample periods between successive inverted samples, and further comprising a counter for counting the number of sample periods between inverted samples to extract the supplemental data. ### Claim 19 (depends on 1) An encoded signal produced by the process of claim 1. ### Claim 20 An encoded signal with embedded supplemental data, in which selected bits of the encoded signal have been inverted to represent the supplemental data with the number of bit periods between successive inverted bits representing the embedded data. ### Claim 21 (depends on 1) A storage medium having stored thereon a signal produced by the process of claim 1. ### Claim 22 A method of embedding supplemental data in an signal, comprising the steps of: encoding the signal in accordance with a given encoding process including feeding back the encoded signal to control the encoding; and modifying the signal to represent the supplemental data after encoding the signal and before feeding back the encoded signal to control the encoding. ### Claim 23 A method of embedding supplemental data in a signal, comprising the steps of: unity bit encoding the signal in accordance with a given unity bit encoding process including feeding back the encoded signal to control the encoding; and modifying the signal to represent the supplemental data before feeding back the signal to control the encoding. ### Claim 24 A method of embedding unity bit supplemental data in a signal, comprising the steps of: encoding the signal in accordance with a given encoding process including feeding back the encoded signal to control the encoding; and combining unitary bit supplemental data into the signal before feeding the signal back to control the encoding. ### Claim 25 A method of embedding supplemental data in a signal, comprising the steps of: encoding the signal in accordance with a given encoding process; combining supplemental data into the signal; continuously feeding the combined and encoded signal containing the supplemental data back to the encoding process to control the encoding.