Methods and apparatus for generating signatures

• US 7,783,889 B2
• Filed: 02/19/2007
• Issued: 08/24/2010
• Est. Priority Date: 08/18/2004
• Status: Active Grant

• Current Assignee: The Nielsen Company LLC (MOOD Media Corporation)
• Original Assignee: The Nielsen Company LLC (MOOD Media Corporation)
• Inventors: Srinivasan, Venugopal
• Primary Examiner(s): Moazzami; Nasser
• Assistant Examiner(s): ABEDIN, SHANTO
• Application Number:
  US11/676,452
• Publication Number:
  US 20070274537A1
• Time in Patent Office: 1,282 Days
• Field of Search: 713/160, 713/176, 713/179, 380/202, 380/206, 380/207, 380/239, 380/253, 380/229, 382/100, 382/232, 382/240, 382/191, 381/94.3, 375/134, 704/268, 704/273, 725/19, 725/20
• US Class Current: 713/179
• CPC Class Codes: H04L 2209/601 Broadcast encryption
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: H04N 21/44224 Monitoring of user activity on external systems, e.g. Internet browsing
• CPC Class Codes: H04N 21/44236 Monitoring of piracy processes or activities protecting computer platforms against harmful, malicious or unexpected behaviour or activities using intrusion detection and counter measures G06F21/566; computer virus detection and handling G06F21/56
• CPC Class Codes: H04N 21/4667 Processing of monitored end-user data, e.g. trend analysis based on the log file of viewer selections
• CPC Class Codes: H04N 21/835 Generation of protective data, e.g. certificates protecting software against unauthorised usage in a vending or licensing environment G06F21/10
• CPC Class Codes: H04N 21/84 Generation or processing of descriptive data, e.g. content descriptors systems specially adapted for using meta-information in broadcast systems H04H60/73
• CPC Class Codes: H04N 7/173 with two-way working, e.g. subscriber sending a programme selection signal

Abstract

Methods, apparatus, and articles of manufacture for media monitoring are disclosed. In particular, the example methods, apparatus, and articles of manufacture generate digital spectral signatures for use in identifying media information. Initially, a frame of media samples is obtained. A first frequency component having a first spectral power and a second frequency component having a second spectral power are identified by performing a spectral transform operation on the frame of media samples. A descriptor of the first frame of media samples is determined based on a comparison of the first spectral power and the second spectral power. A first signature is then generated based on the descriptor.

Claims

1. A method for generating signatures implemented using an apparatus comprising a processor, the method comprising:

obtaining a first frame of media samples;

identifying a first frequency component having a first spectral power and a second frequency component having a second spectral power by performing a spectral transform operation on the first frame of media samples;

determining a first descriptor of the first frame of media samples based on a comparison of the first spectral power and the second spectral power;

generating a first signature based on the first descriptor;

identifying a second frame of media samples by extracting a common plurality of media samples from the first frame of media samples and appending another plurality of media samples to the common plurality of media samples;

identifying a third spectral power associated with a third frequency component and a fourth spectral power associated with a fourth frequency component, wherein the third frequency component and the fourth frequency component are associated with performing the spectral transform operation on the second frame of media samples;

determining a second descriptor based on a comparison of the third spectral power and the fourth spectral power; and

generating a second signature based on the second descriptor.

2. A method as defined in claim 1, further comprising identifying media information based on the first signature.

3. A method as defined in claim 2, wherein a Hamming distance is used to identify the media information based on the first signature.

4. A method as defined in claim 2, wherein the media information is associated with at least one of audio information or video information.

5. A method as defined in claim 1, wherein the first descriptor is associated with only the first frame of media samples.

6. A method as defined in claim 1, wherein the second descriptor is of the second frame of media samples.

7. A method as defined in claim 1, wherein the spectral transform operation is a sliding Fast Fourier Transform.

8. An apparatus for generating signatures, comprising:

a processor system including a memory; and

instructions stored in the memory that enable the processor system to;

obtain a first and second frames of media samples, the first and second frames of media samples consecutively located in an audio stream, a portion of the first frame of media samples overlapping with a portion of the second frame of media samples;

identify a first frequency component having a first spectral power and a second frequency component having a second spectral power by performing a spectral transform operation on the first frame of media samples;

identify a third spectral power and a fourth spectral power;

determine a first descriptor of the first frame of media samples based on a comparison of the first spectral power and the second spectral power;

determine a second descriptor of the second frame of media samples based on a comparison of the third spectral power and the fourth spectral power; and

generate a first signature based on the first descriptor and a second signature based on the second descriptor.

9. An apparatus as defined in claim 8, wherein the instructions stored in the memory enable the processor system to identify media information based on the first signature.

10. An apparatus as defined in claim 9, wherein a Hamming distance is used to identify the media information based on the first signature.

11. An apparatus as defined in claim 8, wherein the first descriptor is associated with only the first frame of media samples.

12. An apparatus as defined in claim 8, wherein the instructions stored in the memory enable the processor system to:

obtain a first plurality of media samples; and

identify the second frame of media samples by extracting a common plurality of media samples from the first frame of media samples and appending the first plurality of media samples to the common plurality of media samples, the common plurality of media samples including the overlapping portions of the first and second frames of media samples.

13. An apparatus as defined in claim 8, wherein the third spectral power is associated with a third frequency component and the fourth spectral power is associated with a fourth frequency component, and wherein the third frequency component and the fourth frequency component are associated with performing the spectral transform operation on the second frame of media samples.

14. A tangible machine accessible medium having instructions stored thereon that, when executed, cause a machine to:

obtain a first frame first and second frames of media samples, the first and second frames of media samples consecutively located in an audio stream, a portion of the first frame of media samples overlapping with a portion of the second frame of media samples;

identify a first frequency component having a first spectral power and a second frequency component having a second spectral power by performing a spectral transform operation on the first frame of media samples;

identify a third spectral power and a fourth spectral power;

determine a first descriptor of the first frame of media samples based on a comparison of the first spectral power and the second spectral power;

determine a second descriptor of the second frame of media samples based on a comparison of the third spectral power and the fourth spectral power; and

generate a first signature based on the first descriptor and a second signature based on the second descriptor.

15. A tangible machine accessible medium as defined in claim 14, wherein the first descriptor is associated with only the first frame of media samples.

16. A tangible machine accessible medium as defined in claim 14 having instructions stored thereon that, when executed, cause the machine to:

obtain a first plurality of media samples; and

identify the second frame of media samples by extracting a common plurality of media samples from the first frame of media samples and appending the first plurality of media samples to the common plurality of media samples, the common plurality of media samples including the overlapping portions of the first and second frames of media samples.

17. A tangible machine accessible medium as defined in claim 14, wherein third spectral power is associated with a third frequency component and the fourth spectral power is associated with a fourth frequency component, and wherein the third frequency component and the fourth frequency component are associated with performing the spectral transform operation on the second frame of media samples.