Detection of out-of-phase low visibility watermarks

• US 20020067844A1
• Filed: 08/20/2001
• Published: 06/06/2002
• Est. Priority Date: 05/08/1995
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Cattone, Jeremy, Reed, Alastair
• Granted Patent: US 6,763,123 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: B42D 25/00 Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof printing processes to produce identification or security features B41M3/14
• CPC Class Codes: B42D 25/333 Watermarks
• CPC Class Codes: B42D 25/382 absorbing or reflecting infrared light
• CPC Class Codes: G06F 16/955 using information identifiers, e.g. uniform resource locators [URL]
• CPC Class Codes: G06K 19/06009 with optically detectable marking G06K19/063, G06K19/08 take precedence
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 19/06046 Constructional details
• CPC Class Codes: G06K 19/14 the marking being sensed by radiation
• CPC Class Codes: G06K 19/18 Constructional details
• CPC Class Codes: G06K 2019/06253 for a specific application
• CPC Class Codes: G06K 7/1417 2D bar codes
• CPC Class Codes: G06K 7/1447 extracting optical codes from image or text carrying said optical code
• CPC Class Codes: G06Q 20/341 Active cards, i.e. cards including their own processing means, e.g. including an IC or chip
• CPC Class Codes: G06Q 20/40145 Biometric identity checks
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 1/0042 Fragile watermarking, e.g. so as to detect tampering
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06V 30/40 Document-oriented image-based pattern recognition
• CPC Class Codes: G07C 9/253 visually
• CPC Class Codes: G07D 7/0034 using watermarks
• CPC Class Codes: G07D 7/004 : using digital security elements, e.g. information coded on a magnetic thread or strip
• CPC Class Codes: G07F 17/16 : for devices exhibiting advertisements, announcements, pictures or the like
• CPC Class Codes: G07F 7/086 : by passive credit-cards adapted therefor, e.g. constructive particularities to avoid counterfeiting, e.g. by inclusion of a physical or chemical security-layer for security documents G07D7/00; for the reading of record-carriers in general G06K7/00; for the design of coded credit-cards G06K19/10
• CPC Class Codes: G07F 7/1008 : Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system
• CPC Class Codes: G10L 19/018 : Audio watermarking, i.e. embedding inaudible data in the audio signal
• CPC Class Codes: 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
• CPC Class Codes: G11B 20/00884 : involving a watermark, i.e. a barely perceptible transformation of the original data which can nevertheless be recognised by an algorithm
• CPC Class Codes: G11B 20/00891 : embedded in audio data
• CPC Class Codes: H04N 1/00005 : relating to image data
• CPC Class Codes: H04N 1/00037 : Detecting, i.e. determining the occurrence of a predetermined state H04N1/00031 takes precedence
• CPC Class Codes: H04N 1/00079 : remotely
• CPC Class Codes: H04N 1/32122 : in a separate device, e.g. in a memory or on a display separate from image data
• CPC Class Codes: H04N 1/32149 : Methods relating to embedding, encoding, decoding, detection or retrieval operations
• CPC Class Codes: H04N 1/32154 : Transform domain methods H04N1/32309 takes precedence
• CPC Class Codes: H04N 1/3216 : using Fourier transforms
• CPC Class Codes: H04N 1/32203 : Spatial or amplitude domain methods H04N1/32309 takes precedence
• CPC Class Codes: H04N 1/32208 : involving changing the magnitude of selected pixels, e.g. overlay of information or super-imposition H04N1/32219, H04N1/32224 take precedence
• CPC Class Codes: H04N 1/32229 : with selective or adaptive application of the additional information, e.g. in selected regions of the image H04N1/32213 takes precedence
• CPC Class Codes: H04N 1/32251 : in multilevel data, e.g. greyscale or continuous tone data
• CPC Class Codes: H04N 1/32288 : Multiple embedding, e.g. cocktail embedding, or redundant embedding, e.g. repeating the additional information at a plurality of locations in the image
• CPC Class Codes: H04N 1/32293 : Repeating the additional information in a regular pattern
• CPC Class Codes: H04N 1/32309 : in colour image data
• CPC Class Codes: H04N 1/32352 : Controlling detectability or arrangements to facilitate detection or retrieval of the embedded information, e.g. using markers for decoding, detection or retrieval operations H04N1/32149 and subgroups take precedence
• CPC Class Codes: H04N 19/467 : characterised by the embedded information being invisible, e.g. watermarking
• CPC Class Codes: H04N 21/23892 : involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level
• CPC Class Codes: 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
• CPC Class Codes: H04N 2201/3205 : of identification information, e.g. name or ID code H04N2201/3209 takes precedence
• CPC Class Codes: H04N 2201/3207 : of an address
• CPC Class Codes: H04N 2201/3225 : of data relating to an image, a page or a document
• CPC Class Codes: H04N 2201/3226 : of identification information or the like, e.g. ID code, index, title, part of an image, reduced-size image
• CPC Class Codes: H04N 2201/3233 : of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/327 : which are undetectable to the naked eye, e.g. embedded codes
• CPC Class Codes: H04N 2201/3271 : Printing or stamping
• CPC Class Codes: H04N 2201/3274 : Storage or retrieval of prestored additional information
• CPC Class Codes: H04N 2201/3284 : for error correction

Abstract

The present invention relates to detecting digital watermarks. In a preferred embodiment, media is embedded with a digital watermark component. The media includes a cyan color plane, a magenta color plane, a yellow color plane, and a black color plane. The digital watermark component is embedded in the cyan, magenta, and yellow color planes. The digital watermark component is inverted and is embedded in the black color plane. The embedded media is illuminated with infrared light, which emphasizes the black color plane. An input device captures a digital image of the illuminated media. The digital watermark component is detected from the emphasized black plane.

Claims

1. A method to detect an out-of-phase digital watermark, the out-of-phase digital watermark embedded in media, said method comprising the steps of:

illuminating the embedded media with infrared light;

capturing an image of the illuminated media; and

analyzing the captured illuminated image to detect the out-of-phase digital watermark.

2. The method according to claim 1, wherein the out-of-phase digital watermark comprises at least a first component and a second component.

3. The method according to claim 2, wherein the first component is embedded in at least a first color plane, and the second component is embedded in at least a black color plane.

4. The method according to claim 3, wherein the second component is inverted with respect to the first component.

5. The method according to claim 4, wherein said black color plane includes black ink comprising carbon.

6. The method according to claim 1, further comprising the step of shielding the media from visible light.

7. The method according to claim 1, further comprising the step of filtering visible light before said step of capturing an image.

8. A method to detect a digital watermark embedded in media comprising the steps of:

illuminating the media with infrared light; and

detecting the digital watermark from the illuminated media.

9. The method according to claim 8, wherein the digital watermark comprises an out-of-phase digital watermark.

10. The method according to claim 9, wherein the media includes a plurality of colors and the out-of-phase digital watermark includes at least a first component and a second component, wherein the second component is embedded out-of-phase with respect to the first component.

11. The method according to claim 10, wherein the plurality of colors includes at least black and the second component is embedded in the black color.

13. The apparatus according to claim 12, further comprising electronic processing circuitry to process digital watermark detecting software instructions for detecting the digital watermark in a captured image.

14. The apparatus according to claim 13, wherein said camera comprises an infrared-pass filter.

15. The apparatus according to claim 14, wherein said digital watermark comprises an out-of-phase digital watermark.

16. The apparatus according to claim 12, further comprising an opaque housing to shield at least said input device.

17. The apparatus according to claim 12, wherein said input device comprises at least one of a digital camera and a web camera.

20. The method according to claim 19, wherein said isolating step comprises the step of illuminating the plurality of color plane with infrared light.

21. The method according to claim 20, wherein the digital watermark comprises an out-of-phase digital watermark.

12. Apparatus to detect a digital watermark comprising:

an infrared illumination source to illuminate media embedded with a digital watermark; and

an input device to capture an image of the media illuminated by said infrared illumination source.

18. Apparatus to detect an out-of-phase digital watermark embedded in media comprising:

means for illuminating the media with infrared light;

means for capturing an image of the illuminated media; and

means for analyzing the captured image to detect the out-of-phase digital watermark.

19. A method to detect a digital watermark embedded in at least a first of a plurality of color planes, said method comprising the steps of:

isolating the first color plane from the plurality of color planes; and

analyzing the isolated color plane to detect the embedded digital watermark.