Methods and apparatus to detect a blank frame in a digital video broadcast signal

• US 7,984,462 B2
• Filed: 09/25/2006
• Issued: 07/19/2011
• Est. Priority Date: 03/29/2004
• Status: Expired due to Fees

• Current Assignee: The Nielsen Company LLC (MOOD Media Corporation)
• Original Assignee: The Nielsen Company LLC (MOOD Media Corporation)
• Inventors: Deng, Kevin K.
• Primary Examiner(s): Koenig; Andrew Y
• Assistant Examiner(s): Le; Rong
• Application Number:
  US11/534,790
• Publication Number:
  US 20070083883A1
• Time in Patent Office: 1,758 Days
• Field of Search: 348/700, 725 10- 25, 725/41, 725/51, 382/181
• US Class Current: 725/19
• CPC Class Codes: G01R 19/0015 separating AC and DC
• CPC Class Codes: G11B 27/28 by using information signals recorded by the same method as the main recording G11B27/22 takes precedence
• CPC Class Codes: H04H 60/32 Arrangements for monitoring conditions of receiving stations, e.g. malfunction or breakdown of receiving stations
• CPC Class Codes: H04H 60/37 for identifying segments of broadcast information, e.g. scenes or extracting programme ID
• CPC Class Codes: H04N 19/15 by monitoring actual compressed data size at the memory before deciding storage at the transmission buffer
• CPC Class Codes: H04N 21/25866 Management of end-user data customer care in data networks H04L41/5077
• CPC Class Codes: H04N 21/44008 involving operations for analysing video streams, e.g. detecting features or characteristics in the video stream arrangements characterised by components specially adapted for monitoring, identification or recognition of video in broadcast systems H04H60/59
• CPC Class Codes: H04N 21/6582 Data stored in the client, e.g. viewing habits, hardware capabilities, credit card number arrangements where receivers interact with the broadcast H04H20/38
• CPC Class Codes: H04N 21/812 involving advertisement data advertising per se G06Q30/02
• CPC Class Codes: H04N 5/45 Picture in picture , e.g. displaying simultaneously another television channel in a region of the screen
• CPC Class Codes: H04N 5/85 on discs or drums
• CPC Class Codes: H04N 5/907 using static stores, e.g. storage tubes or semiconductor memories H04N5/91 takes precedence

Abstract

Methods and apparatus to detect blank images in a digital video broadcast signal are disclosed. An example method of detecting a blank image includes analyzing DC values of luminance blocks associated with a frame to determine a number of the luminance blocks having substantially the same DC value; and identifying the frame as a blank image if the number exceeds a predetermined threshold.

Claims

1. A method of detecting a blank image comprising:

analyzing a compressed frame of a tuned digital broadcast signal to determine if the frame is a blank candidate by determining if the compressed frame has a data size less than a first threshold and determining if more than a second threshold number of areas of the compressed frame includes substantially a same number of at least one of bits or bytes of data, wherein analyzing the compressed frame is performed without extracting DC values from the compressed frame; and

when the compressed frame is the blank candidate, extracting and analyzing at least some of the DC values from the compressed frame to determine if the blank candidate is a blank image by comparing a number of the DC values having substantially a same value to a third threshold.

2. A method as defined in claim 1 wherein the data size comprises a number of bits in substantially the entire compressed frame.

3. A method as defined in claim 1 wherein each of the areas has substantially a same size.

4. A method as defined in claim 1 wherein the areas comprise rows of the frame.

5. A method as defined in claim 4 wherein determining if more than a second threshold number of areas of the compressed frame includes substantially the same number of at least one of bits or bytes of data comprises determining if at least a percentage of the rows are allocated less than a threshold number of bits.

6. A method as defined in claim 1 wherein analyzing at least some of the DC values from the compressed frame to determine if the blank candidate is the blank image comprises analyzing one area of the blank candidate, the one area being less than the entire blank candidate.

7. A method as defined in claim 6 wherein the analyzed area comprises one slice of the blank candidate.

8. A method as defined in claim 6 wherein comparing a number of the DC values having substantially a same value to a third threshold comprises determining if more than a number of codes representing zero change in brightness are located in the area.

9. A method as defined in claim 1 wherein the at least some of the DC values are from a same slice of the blank candidate.

10. An apparatus to detect a blank image comprising:

a blank frame candidate identifier to analyze a compressed frame of a tuned digital broadcast signal to determine if the frame is a blank candidate without extracting DC values from the compressed frame, the blank frame candidate identifier to analyze the compressed frame by determining if the compressed frame has a data size less than a first threshold and determining if more than a second threshold number of areas of the compressed frame includes substantially a same number of at least one of bits or bytes of data; and

a blank frame tester to extract and analyze at least some of the DC values from the compressed frame to determine if the blank candidate is a blank image, the blank frame tester to determine if the blank frame candidate is a blank image by comparing a number of DC values having substantially a same value to a second threshold.

11. An apparatus as defined in claim 10 wherein the data size comprises a number of bits in substantially the entire compressed frame.

12. An apparatus as defined in claim 10 wherein each of the areas has substantially a same size.

13. An apparatus as defined in claim 10 wherein the areas comprise rows of the frame.

14. An apparatus as defined in claim 13 wherein the blank frame candidate identifier is to determine if more than a second threshold number of areas of the compressed frame includes substantially the same number of at least one of bits or bytes of data by determining if at least a percentage of the rows are allocated less than a threshold number of bits.

15. An apparatus as defined in claim 10 wherein the blank frame tester is to extract and analyze at least some of the DC values from the compressed frame by analyzing an area of the blank candidate.

16. An apparatus as defined in claim 15 wherein the analyzed area comprises one slice of the blank candidate.