Method of detecting and extracting a watermark

Patent metadata

Field	Value
Publication number	US-10026139-B2
Application number	US-201415033040-A
Country	US
Kind code	B2
Filing date	Oct 30, 2014
Priority date	Oct 31, 2013
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

A method of detecting and extracting a watermark (digital watermarking) in a digital signal. The watermark is composed by the repetition of elementary components of a load to be transmitted. At least one repetition of an elementary component in the digital signal is detected. At least one quality attribute is assigned to each repetition of at least one elementary component. The repetitions of an elementary component are sorted according to a function of the quality attributes of these repetitions. Certain repetitions, dubbed individualities, of an elementary component are selected. The selected repetitions are fused.

First claim

The invention claimed is:

1. A method of detecting and extracting a watermark, a digital watermarking, in a digital signal, said watermark being composed by a repetition of elementary components, said method comprising the steps of:
detecting at least one repetition of an elementary component in the digital signal to provide a data sample dubbed an individuality of said elementary component, said at least one repetition being a binary bit;
determining at least one quality attribute of each repetition of at least one elementary component, said at least one quality attribute being a bit error rate, a reliable repetition having a lower bit rate than an erroneous repetition;
classifying the repetitions of said elementary component according to said at least one quality attribute of these repetitions to identify erroneous repetitions;
selecting the repetitions, dubbed individualities, of said elementary component according to a classification of the repetitions to discard the erroneous repetitions and to keep reliable repetitions of said elementary component; and
merging the reliable repetitions by a weighted summation, a weight of each reliable repetition being determined as a function of said at least one quality attribute of said each reliable repetition, to detect and extract the watermark in the digital signal.

2. The method as claimed in claim 1 , wherein the quality attribute of each repetition of said elementary component is the reliability of this repetition.

3. The method as claimed in claim 1 , further comprising the step of classifying the repetitions of one and the same elementary component by decreasing bit error rate.

4. The method as claimed in claim 1 , further comprising the step of discarding the erroneous repetitions from a final process of determining a value to be retained for the elementary component.

5. The method as claimed in claim 1 , wherein the elementary components are binary.

6. The method as claimed in claim 1 , wherein the elementary components are real quantities, values of the elementary components are in a set of real numbers.

7. The method as claimed in claim 1 , further comprising a step of grouping the classification of the repetitions into two classes: a class of winning individualities and a class of minor individualities.

8. The method as claimed in claim 7 , further comprising the step of evaluating a boundary between domains of the winning individualities and of the minor individualities by a statistical computation on a total or partial population of the repetitions of the elementary components.

9. The method as claimed in claim 7 wherein a merger of the winning individualities arising from the repetition of one and the same elementary component is carried out by summation.

10. The method as claimed in claim 1 , wherein the digital signal is representative of a still image.

11. The method as claimed in claim 1 , wherein the digital signal is representative of a sequence of moving images.

12. The method as claimed in claim 1 , wherein the digital signal is representative of a sound sequence.

13. A digital watermark decoding device for detecting and extracting a watermark, a digital watermarking, in a digital signal, said watermark being composed by a repetition of elementary components, the digital watermark decoding device detects at least one repetition of an elementary component in the digital signal to provide a data sample dubbed an individuality of said elementary component; determines at least one quality attribute of each repetition of at least one elementary component, said at least one quality attribute being a bit error rate, a reliable repetition having a lower bit rate than an erroneous repetition; classifies the repetitions of said elementary component according to said at least one quality attribute of these repetitions to identify erroneous repetitions; selects the repetitions, dubbed individualities, of said elementary component according to a classification of the repetitions to discard the erroneous repetitions and to keep reliable repetitions of said elementary component; and merges the reliable repetitions by a weighted summation, a weight of each reliable repetition being determined as a function of said at least one quality attribute of said each reliable repetition, to detect and extract the watermark in the digital signal.

Assignees

• Dolby Laboratories Licensing Corp

Inventors

• Nguyen Philippe
• Rizko Camille

Classifications

• G06T1/0071 Primary

  using multiple or alternating watermarks · CPC title

• H04N1/32293

  Repeating the additional information in a regular pattern · CPC title

• G10L19/018

  Audio watermarking, i.e. embedding inaudible data in the audio signal · CPC title

• G06T2201/0053

  Embedding of the watermark in the coding stream, possibly without decoding; Embedding of the watermark in the compressed domain · CPC title

• G06T1/005 Primary

  Robust watermarking, e.g. average attack or collusion attack resistant · CPC title