Fast signal detection and distributed computing in portable computing devices

• US 20060031684A1
• Filed: 08/05/2005
• Published: 02/09/2006
• Est. Priority Date: 08/06/2004
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Sharma, Ravi K., Rodriguez, Tony F.
• Granted Patent: US 8,694,049 B2
• Time in Patent Office: Days
• US Class Current: 713/186
• CPC Class Codes: G05B 2219/24162 Biometric sensor, fingerprint as user access password
• CPC Class Codes: G06F 16/683 using metadata automatically derived from the content
• CPC Class Codes: G06F 2218/02 Preprocessing
• CPC Class Codes: G06F 2218/10 by analysing the shape of a waveform, e.g. extracting parameters relating to peaks
• CPC Class Codes: G06T 1/0064 Geometric transfor invariant watermarking, e.g. affine transform invariant
• CPC Class Codes: G06T 2201/0052 Embedding of the watermark in the frequency domain
• CPC Class Codes: G10L 25/18 the extracted parameters being spectral information of each sub-band
• CPC Class Codes: G10L 25/21 the extracted parameters being power information
• CPC Class Codes: H04M 1/0264 for a camera module assembly
• CPC Class Codes: H04N 1/00204 with a digital computer or a digital computer system, e.g. an internet server programmed control between transmitter and receiver or between image input and image output device H04N1/32561
• CPC Class Codes: H04N 1/00244 with a server, e.g. an internet server fax-servers or the like for store and forward H04N1/324
• CPC Class Codes: H04N 1/00307 with a mobile telephone apparatus constructional features of portable telephone sets H04M1/0202; mobile radio systems H04W84/00
• CPC Class Codes: H04N 1/00358 Type of the scanned marks
• CPC Class Codes: H04N 1/00363 Bar codes or the like
• CPC Class Codes: H04N 1/00973 from a remote device, e.g. receiving via the internet instructions input to a computer terminal
• CPC Class Codes: H04N 1/32117 in a separate transmission or protocol signal prior to or subsequent to the image data transmission, e.g. in digital identification signal [DIS], in non standard setup [NSS] or in non standard field [NSF] for mode signalling H04N1/333
• CPC Class Codes: H04N 1/32144 embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
• CPC Class Codes: H04N 1/3216 using Fourier transforms
• CPC Class Codes: H04N 2201/0096 Portable devices
• 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 2201/3278 : Transmission
• CPC Class Codes: H04W 88/02 : Terminal devices

Abstract

This disclosure describes a distributed reader architecture for a mobile computing device such as cellular telephone handset. This architecture includes a reader library that reads device capabilities and business model parameters in the device, and in response, for selects an appropriate configuration of reader modules for identifying a content item. The reader modules each perform a function used in identifying a content item. The modules are selected so that the resources available on the device and in remote devices are used optimally, depending on available computing resources on the device and network bandwidth. One example of a reader module is a fast watermark detection module that quickly detects the presence of a watermark, enabling resources to be focused on portions of content that are most likely going to lead to successful content identification. A watermark signal structure for fast watermark detection is comprised of a dense array of impulse functions in a form of a circle in a Fourier magnitude domain, and the impulse functions having pseudorandom phase. Alternative structures are possible.

Claims

1. A reader for a mobile telephone handset comprising:

a reader library for reading device capabilities or business model parameters and in response, for selecting a configuration of reader modules for identifying a content item; and

reader modules, each for performing a function used in identifying a content item.

2. The reader of claim 1 wherein the reader modules include a pre-filter to provide a filtered signal used for identifying the content item from a host signal captured on the handset.

3. The reader of claim 2 wherein a content fingerprint is derived from the filtered signal, and the fingerprint is used for identifying the content item.

4. The reader of claim 2 wherein the pre-filter is executed on the mobile telephone handset and identifying the content item from the filtered signal is performed on a device remote from the handset.

5. The reader of claim 2 wherein the reader modules include a digital watermark detection module for identifying the content item based on a watermark extracted from the host signal.

6. The reader of claim 1 wherein the reader modules include a fast detect module and a full detect module used for identifying the content item from a host signal captured on the handset.

7. The reader of claim 6 wherein the fast detect module is executed on the handset and the full detect module is executed on a device remote from the handset to identify the content item.

8. The reader of claim 1 wherein the reader modules include a fingerprint module for computing a hash of a host signal captured on the handset for identifying the content item from the host signal.

9. The reader of claim 8 wherein the reader modules include a digital watermark detector.

10. The reader of claim 9 wherein the digital watermark detector and fingerprint module operate on the host signal for identifying the content item from a host signal captured on the handset.

11. The reader of claim 1 wherein the device capabilities or business model parameters comprise processor capabilities.

12. The reader of claim 1 wherein the device capabilities or business model parameters comprise parameters associated with a service provider or calling plan for wireless communication.

13. The reader of claim 1 wherein the device capabilities or business model parameters comprise network bandwidth available to the handset.

14. A method for identifying a content item from a host signal captured on a mobile telephone handset, the method comprising:

in a server, receiving data derived from the host signal for use in identifying the content item, an identification method being selected from among alternative identification methods based on device capabilities or business model parameters of the handset;

in response to receiving the data in the server, identifying the content item from the data according to the selected identification method; and

determining an action associated with the content item.

15. The method of claim 14 wherein the action includes returning data associated with the content item for rendering on the handset.

16. The method of claim 14 wherein the identification method is selected based on processor capabilities of the handset.

17. The method of claim 14 wherein the identification method is selected based on a business model parameter relating to a wireless service provider or plan.

18. A watermark signal structure on a tangible medium for fast watermark detection, the structure comprising:

a dense array of impulse functions in a form of a circle in a Fourier magnitude domain, the impulse functions having pseudorandom phase.

19. A method for detection of an embedded signal in an image signal, the method comprising:

receiving an image signal including an embedded array of impulse functions in a frequency domain of the image signal;

computing a frequency domain transformation of the image signal;

computing a one dimensional projection of the frequency domain transformation;

and detecting a peak in the projection to detect the embedded array of impulse functions.

20. The method of claim 19 wherein the embedded array of impulse functions form a circle in a Fourier magnitude domain, and the impulse functions have pseudorandom phase.