Extending watermark detection distortion tolerances

• US 9,710,870 B2
• Filed: 03/03/2015
• Issued: 07/18/2017
• Est. Priority Date: 03/05/2010
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Reed, Alastair M., Sharma, Ravi K.
• Primary Examiner(s): Bayat, Ali
• Application Number:
  US14/637,121
• Publication Number:
  US 20150242981A1
• Time in Patent Office: 868 Days
• Field of Search: 382100
• CPC Class Codes: G06F 18/00 Pattern recognition
• CPC Class Codes: G06T 1/00 General purpose image data processing
• 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 1/0085 Time domain based watermarking, e.g. watermarks spread over several images
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0065 Extraction of an embedded watermark; Reliable detection

Abstract

The present disclosures relates generally to digital watermarking and data hiding. One claim recites a smartphone comprising: a camera to capture video of a display that is rendering video, in which the video comprises a first watermark signal embedded in a first portion of the data, a second watermark signal embedded in a second portion of the data, and a third watermark signal embedded in a third portion of the data, in which at least two of the first watermark signal, second watermark signal and third watermark signal are inversely related to one another; electronic memory for buffering data representing captured video; one or more electronic processors programmed for: applying a first perspective distortion to the data representing the captured video to yield first perspective distorted video; and analyzing the first perspective distorted video to detect digital watermarking, in which a second perspective distortion is applied to the data representing the captured video to yield second perspective distorted video when the analyzing does not detect digital watermarking, and then performing analyzing the second perspective distorted video to detect digital watermarking. Of course, other claims are provided too.

Claims

1. A method comprising:

generating a watermark signal;

using one or more programmed electronic processors, transforming color imagery by embedding a watermark signal in a first portion of the color imagery, the watermark signal being associated with a first embedding size at which alterations corresponding to the watermark signal are to be made, the first embedding size being associated with an n×

m pixel area where n and m are both integers;

adjusting the first embedding size associated with the watermark signal in a first manner to allow expanded detection of the watermark signal in the presence of first distortion, said adjusting yielding a second embedding size, the second embedding size being associated with an a×

b pixel area, in which a and b are both integers and are both different from n and m; and

using one or more programmed electronic processors, transforming the color imagery by embedding the watermark signal with the second embedding size as adjusted from the first embedding size in the first manner in a second portion of the color imagery.

2. The method of claim 1 in which the first distortion is due to positive image capture perspective angle variance.

3. The method of claim 2 in which image capture perspective angle variance is introduced by a mobile device capturing imagery of color imagery.

4. The method of claim 1 in which the color imagery comprises color video.

5. A method comprising:

generating a watermark signal;

using one or more programmed electronic processors, transforming color imagery by embedding a watermark signal in a first portion of the color imagery, in which said transforming color imagery by embedding the watermark signal in the first portion of the color imagery uses a first embedding bump size, in which the first embedding bump size corresponds with a first detection range distance when capturing optical scan data associated with the color imagery,

preconditioning the watermark signal in a first manner to allow expanded detection of the preconditioned watermark signal in the presence of first distortion; and

using one or more programmed electronic processors, transforming the color imagery by embedding the watermark signal preconditioned in the first manner in a second portion of the color imagery, and in which said transforming color imagery by embedding the watermark signal preconditioned in the first manner in a second portion of the color imagery uses a second embedding bump size that corresponds with a second detection range distance when capturing optical scan data associated with the color imagery, in which the second detection range distance comprises a larger detection range distance relative to the first detection range distance.

6. An apparatus comprising:

memory for storing a watermark signal;

one or more programmed electronic processors configured for;

altering color imagery by embedding a watermark signal in a first portion of the color imagery, the watermark signal being associated with a first embedding size at which alterations corresponding to the watermark signal are to be made, the first embedding size being associated with an n×

m pixel area where n and m are both integers;

adjusting the first embedding size associated with the watermark signal in a first manner to allow expanded detection of the watermark signal in the presence of first distortion, the second embedding size being associated with an a×

b pixel area, in which a and b are both integers and are both different from n and m; and

altering the color imagery by embedding the watermark signal with the second embedding size as adjusted from the first embedding size in the first manner in a second portion of the color imagery.

7. The apparatus of claim 6 in which the first distortion is due to positive image capture perspective angle variance.

8. The apparatus of claim 7 in which image capture perspective angle variance is introduced by a mobile device capturing imagery of color imagery.

9. The apparatus of claim 7 in which the color imagery comprises color video.

10. An apparatus comprising:

memory for storing a watermark signal;

one or more programmed electronic processors configured for;

altering color imagery by embedding a watermark signal in a first portion of the color imagery, in which said altering color imagery by embedding the watermark signal in the first portion of the color imagery uses a first embedding bump size, in which the first embedding bump size corresponds with a first detection range distance when capturing optical scan data associated with the color imagery;

preconditioning the watermark signal in a first manner to allow expanded detection of the preconditioned watermark signal in the presence of first distortion; and

altering the color imagery by embedding the watermark signal preconditioned in the first manner in a second portion of the color imagery, and in which said altering color imagery by embedding the watermark signal preconditioned in the first manner in a second portion of the color imagery uses a second embedding bump size that corresponds with a second detection range distance when capturing optical scan data associated with the color imagery, in which the second detection range distance comprises a larger detection range distance relative to the first detection range distance.