Detecting Media Areas Likely of Hosting Watermarks

• US 20080149713A1
• Filed: 10/23/2007
• Published: 06/26/2008
• Est. Priority Date: 08/13/2003
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Brundage, Trent J.
• Granted Patent: US 8,301,893 B2
• Time in Patent Office: Days
• US Class Current: 235/435
• CPC Class Codes: G06T 1/0071 using multiple or alternating watermarks
• CPC Class Codes: G06T 2201/0601 whereby calibration information is embedded in the watermark, e.g. a grid, a scale, a list of transformations
• CPC Class Codes: G07D 7/0043 using barcodes
• CPC Class Codes: G07D 7/0047 using checkcodes, e.g. coded numbers derived from serial number and denomination
• CPC Class Codes: G07D 7/0053 involving markings added to a pattern, e.g. interstitial points
• CPC Class Codes: G07D 7/04 Testing magnetic properties of the materials thereof, e.g. by detection of magnetic imprint G07D7/01 takes precedence
• CPC Class Codes: G07F 7/082 Features insuring the integrity of the data on or in the card

Abstract

The present invention relates generally to digital watermarking and steganographic encoding. One claim recites a method including: receiving data corresponding to at least a portion of digital data; separating the data into a plurality of portions; determining a measure relative to a predetermined measure for each of the portions, wherein the measure comprises a measure related to a predetermined digital watermark signal; based at least in part on the measure, identifying which out of the plurality of portions are likely to host digital watermarking therein. Of course, other combinations are provided as well.

Claims

1. A method of identifying portions of digital data, the digital data corresponding to a printed document, the printed document including first and second different areas conveying first and second different digital watermarks, respectively, wherein the first digital watermark includes a first orientation component and the second digital watermark includes a second orientation component, and wherein the identified portions of the digital data are suspected to include digital watermark data, the method comprising:

segregating the digital data into a plurality of windows;

for each of the plurality of windows, determining an orientation measure;

grouping the windows based on orientation measure; and

selecting at least two of the groups based on at least one of a number of windows assigned to a group and a collective watermark strength for a group, wherein the windows within the selected groups include the portions of the digital data that are suspected to include digital watermark data.

2. The method of claim 1 wherein the two groups are distinguished based on orientation measure.

3. The method of claim 1 wherein the orientation measure comprises a relative scale and a relative rotation.

4. The method of claim 3 wherein the orientation measure further comprises a relative translation.

5. The method of claim 1, further comprising analyzing only the windows within the two groups to detect a watermark message.

6. The method of claim 1 wherein the printed document comprises at least one of an identification document and a financial document.

7. The method of claim 1 wherein the grouping comprises generating a histogram.

8. The method of claim 7 wherein the histogram represents a number of windows over given orientations.

9. The method of claim 1 wherein the histogram identifies predominate watermark orientation components.

10. A method of identifying a first area and a second area of a printed document that are likely to include, respectively, a first digital watermark and a second digital watermark, wherein the first digital watermark includes a first orientation component and the second digital watermark includes a second orientation component, the method comprising:

receiving optically scanned image data that corresponds with at least a portion of the printed document;

segmenting the image data into a plurality of image portions;

determining an orientation measure relative to a predetermined orientation for each of the image portions;

identifying the first area by associating image portions having a first orientation measure; and

identifying the second area by associating image portions having a second orientation measure.

11. The method of claim 10 wherein the first orientation measure and the second orientation measure are each associated with a relatively higher number of image portions when compared to other orientation measures.

12. The method of claim 10 wherein the orientation measure corresponds to a relative scale and a relative rotation.

13. The method of claim 10, wherein the printed document comprises at least one of a financial document and an identification document.

14. The method of claim 10 wherein the first orientation component is embedded so as to represent a first orientation, and wherein the second orientation component is embedded so as to represent a second different orientation.

15. The method of claim 14 wherein the first orientation comprises a first scale, and the second different orientation comprises a second different scale.

16. A method comprising:

receiving data corresponding to at least a portion of digital data;

segmenting the data into a plurality of portions;

determining an orientation measure relative to a predetermined orientation for each of the portions;

identifying a first area by associating portions having a first orientation measure; and

identifying a second area by associating portions having a second orientation measure.

17. The method of claim 16 wherein the first area is identified as being likely to include a first digital watermark associated with a first orientation component, where the.

18. The method of claim 17 wherein the second area is identified as being likely to include a second digital watermark associated with a second orientation component.

19. The method of claim 16 wherein the digital data corresponds to at least one of audio, video or imagery.

20. A method comprising:

receiving data corresponding to at least a portion of digital data;

separating the data into a plurality of portions;

determining a measure relative to a predetermined measure for each of the portions, wherein the measure comprises a measure related to a predetermined digital watermark signal;

based at least in part on the measure, identifying which out of the plurality of portions are likely to host digital watermarking therein.

21. The method of claim 20 wherein the predetermined measure comprises at least one of watermark signal strength or an expected watermark orientation property.

22. The method of claim 21 wherein the expected watermark orientation property comprises at least one of scale, rotation or translation.

23. The method of claim 20 wherein the digital data corresponds to audio, video or imagery.

24. The method of claim 20 wherein the predetermined measure comprises both a watermark correlation measure and a watermark orientation measure.

25. A method to determine whether a media signal has been altered relative to an original media signal, said method comprising:

receiving data corresponding to at least a portion of digital data;

separating the data into a plurality of portions;

first determining a measure for each of the portions, wherein the measure comprises a measure related to a digital watermark signal;

second determining for each of the portions whether the respective measure is relatively different compared to a neighborhood of measure or to an expected measure.

based on said act of second determining, identifying portions which may not correspond to the original media signal.

26. A method to detect a copy of media, the media comprising a first area and a second area including, respectively, a first digital watermark and a second digital watermark, wherein the first digital watermark includes a first orientation component and the second digital watermark includes a second orientation component, said method comprises:

receiving data representing the media;

segmenting the data into a plurality of portions;

determining an orientation parameter for at least some of the portions;

identifying from the determined orientation parameters, at least two relatively prominent orientation parameters;

comparing at least one of;

i) a relationship between at least the two most prominent orientation parameters;

ii) at least the two most prominent orientation parameters to predetermined orientation parameters;

or iii) a relationship between at least the two most prominent orientation parameters and an expected relationship between the two most prominent orientation parameters; and

based on the act of comparing, determining whether the media is an original or is a copy of the media.

27. The method of claim 26 wherein the media comprises a printed document.

28. The method of claim 27 wherein the printed document comprises an identification document, and wherein the first area corresponds with a photographic representation of a bearer of the identification document.

29. The method of claim 26 wherein the orientation parameter comprises rotation and scale.

30. A method of determining areas of media that have a likelihood of including digital watermark information, said method comprising:

receiving digital data corresponding to the media;

analyzing a plurality of portions of the digital data to determine an orientation measure for each of the portions, wherein the orientation measure provides an orientation measure relative to a predetermined orientation measure; and

identifying a predetermined number of orientation measures that have at least one of;

i) a highest number of portions associated therewith; and

ii) a strongest collective watermark strength associated therewith.

31. The method of claim 30 wherein the media comprises imagery.

32. The method of claim 30 wherein the media comprises video or audio.

33. The method of claim 30 wherein the media comprises a printed document.

34. The method of claim 33 wherein the printed document comprises at least one of an identification document and a financial document.

35. The method of claim 30 further comprising analyzing portions that correspond to the identified orientation measures to recover the digital watermark information.

36. The method of claim 35 wherein the identified orientation measures respectively correspond to different digital watermark orientation components.

37. The method of claim 35 wherein prior to said analyzing step, said method further comprises manipulating the portions that correspond to the identified orientation measures to compensate for image distortion identified by the orientation measures.