Digital watermarking in data representing color channels

Patent metadata

Field	Value
Publication number	US-9940685-B2
Application number	US-201514924449-A
Country	US
Kind code	B2
Filing date	Oct 27, 2015
Priority date	Apr 19, 2000
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

The present disclosure relates to digital watermarking. One claim recites a method to detect two or more different digital watermarks in media. The method includes: receiving captured imagery of the media, the captured imagery comprising a plurality of image frames; for a first image frame applying a first watermark detector to search for a first digital watermark hidden within the first image frame, in which an electronic processor is programmed as the first watermark detector; and for a second image frame applying a second, different watermark detector to search for a second, different watermark hidden within the second image frame, in which an electronic processor is programmed as the second watermark detector. Other claims and combinations are provided too.

First claim

What is claimed is:

1. A method comprising:
receiving captured imagery of media, wherein the captured imagery includes a plurality of image frames;
for a first image frame, applying, using an electronic processor, a first watermark detector to search for a first imperceptible digital watermark hidden within the first image frame, wherein the first watermark detector uses a blue phase technique to search for the first imperceptible digital watermark, wherein the first image frame represents a blue channel, a green channel, and a red channel, wherein the first watermark detector uses a detection signal to search for the first imperceptible digital watermark, and wherein the detection signal is calculated using the blue channel, green channel, and the red channel;
for a second image frame, applying, using the electronic processor, a second, different watermark detector to search for a second, different imperceptible watermark hidden within the second image frame;
scaling the blue channel by a first factor;
scaling a sum of the red channel and the green channel by a second factor; and
subtracting the scaled sum of the red channel and green channel from the scaled blue channel as part of the detection signal.

2. The method of claim 1 , wherein the first image frame and the second image frame each represent a same portion of the media.

3. The method of claim 1 , wherein the second image frame is different than the first image frame.

4. The method of claim 1 , wherein first factor is different than the second factor.

5. The method of claim 4 , further comprising shifting the detection signal by a value to avoid color saturation.

6. The method of claim 1 , wherein the first factor is greater than the second factor.

7. The method of claim 1 , wherein the second imperceptible watermark is an orientation component.

8. A system comprising:
an electronic processor configured to:
receive captured imagery of media, wherein the captured imagery includes a plurality of image frames;
for a first image frame, apply a first watermark detector to search for a first digital imperceptible watermark hidden within the first image frame, wherein the first watermark detector uses a blue phase technique to search for the first imperceptible digital watermark wherein the first image frame represents a blue channel, a green channel, and a red channel, wherein the first watermark detector uses a detection signal to search for the first imperceptible digital watermark, and wherein the detection signal is calculated using the blue channel, green channel, and the red channel;
for a second image frame, apply a second, different watermark detector to search for a second, different imperceptible watermark hidden within the second image frame;

scale the blue channel by a first factor;
scale a sum of the red channel and the green channel by a second factor; and
subtract the scaled sum of the red channel and green channel from the scaled blue channel as part of the detection signal.

9. The system of claim 8 , wherein the electronic processor is further configured to shift the detection signal by a value to avoid color saturation.

10. The system of claim 9 , wherein first factor is different than the second factor.

11. A non-transitory computer readable medium having instructions stored thereon, the instructions comprising:
instructions to receive captured imagery of media, wherein the captured imagery includes a plurality of image frames;
instructions to, for a first image frame, apply a first watermark detector to search for a first digital imperceptible watermark hidden within the first image frame, wherein the first watermark detector uses a blue phase technique to search for the first imperceptible digital watermark, wherein the first image frame represents a blue channel, a green channel, and a red channel, wherein the first watermark detector uses a detection signal to search for the first digital imperceptible watermark, and wherein the detection signal is calculated using the blue channel, green channel, and the red channel;
instructions to, for a second image frame, apply a second, different watermark detector to search for a second, different imperceptible watermark hidden within the second image frame;
instructions to scale the blue channel by a first factor;
instructions to scale a sum of the red channel and the green channel by a second factor; and
instructions to subtract the scaled blue channel from the scaled sum of the red channel and green channel as part of the detection signal.

12. The non-transitory computer readable medium of claim 11 , wherein the instructions further comprise instructions to shift the detection signal by a value to avoid color saturation.

Assignees

• Digimarc Corp

Inventors

• Reed Alastair M
• Brundage Trent J

Classifications

• G06T1/0028

  Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking · CPC title

• H04N1/32288

  Multiple embedding, e.g. cocktail embedding, or redundant embedding, e.g. repeating the additional information at a plurality of locations in the image · CPC title

• H04N1/32208

  involving changing the magnitude of selected pixels, e.g. overlay of information or super-imposition (H04N1/32219, H04N1/32224 take precedence) · CPC title

• H04N1/32144

  embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp · CPC title

• H04N1/32229

  with selective or adaptive application of the additional information, e.g. in selected regions of the image (H04N1/32213 takes precedence) · CPC title