Methods, apparatus and articles of manufacture to monitor environments

• US 9,292,923 B2
• Filed: 03/06/2013
• Issued: 03/22/2016
• Est. Priority Date: 03/06/2013
• Status: Active Grant

• Current Assignee: The Nielsen Company LLC (MOOD Media Corporation)
• Original Assignee: The Nielsen Company LLC (MOOD Media Corporation)
• Inventors: Srinivasan, Venugopal, Soundararajan, Padmanabhan
• Primary Examiner(s): Bella, Matthew
• Assistant Examiner(s): SHIN, SOO JUNG
• Application Number:
  US13/787,314
• Publication Number:
  US 20140254880A1
• Time in Patent Office: 1,112 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G01B 11/22 for measuring depth
• CPC Class Codes: G06F 18/22 Matching criteria, e.g. proximity measures
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/10028 Range image; Depth image; 3D point clouds
• CPC Class Codes: G06T 2207/30196 Human being; Person
• CPC Class Codes: G06T 7/248 involving reference images or patches
• CPC Class Codes: G06T 7/50 Depth or shape recovery
• CPC Class Codes: G06T 7/60 Analysis of geometric attributes
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: G06T 7/74 involving reference images or patches
• CPC Class Codes: G06V 40/10 Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
• CPC Class Codes: G06V 40/20 Movements or behaviour, e.g. gesture recognition recognition of facial expressions G06V40/16
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

Methods, apparatus, and articles of manufacture to monitor environments are disclosed. An example method includes analyzing a first depth value corresponding to a coordinate of an object of an image captured by a depth sensor, the first depth value having been captured with the depth sensor positioned at a first angle relative to a reference axis; moving the depth sensor to a second angle relative to the reference axis, the second angle being different than the first angle; triggering capture of a second depth value at the coordinate with the depth sensor positioned at the second angle; and calculating a depth gradient for the coordinate based on the first and second depth values.

Claims

1. A method, comprising:

analyzing, with a processor, a first depth value corresponding to a coordinate of an object of an image captured by a depth sensor, the first depth value having been captured with the depth sensor positioned at a first angle relative to a reference axis;

initiating, with the processor, the depth sensor to move to a second angle relative to the reference axis, the second angle being different than the first angle;

triggering, with the processor, capture of a second depth value at the coordinate with the depth sensor positioned at the second angle; and

calculating, with the processor, a depth gradient for the coordinate based on the first depth value, the second depth value, and a difference between the first angle and the second angle.

2. A method as defined in claim 1, wherein the moving of the depth sensor to the second angle is based on a comparison of the first depth value and a threshold.

3. A method as defined in claim 2, wherein a value of the threshold depends on whether the object, a movement, or a gesture is being analyzed.

4. A method as defined in claim 1, wherein the moving of the depth sensor to the second angle is in response to detecting movement at the coordinate.

5. A method as defined in claim 1, wherein the moving of the depth sensor includes actuating a tilt motor coupled to a housing of the depth sensor.

6. A method as defined in claim 1, further including triggering capture of a third depth value at the coordinate with the depth sensor positioned at a third angle relative to the reference axis, the third angle being different than the first and second angles.

7. A method as defined in claim 6, wherein the calculating of the depth gradient for the coordinate includes consideration of the third depth value.

8. A method as defined in claim 1, wherein the reference axis is a horizontal axis extending away from the depth sensor into the environment.

9. A tangible machine readable storage medium comprising instructions that, when executed, cause a machine to at least:

identify a first depth value corresponding to a coordinate of an object in a first image captured by a depth sensor, the first image having been captured with the depth sensor positioned at a first angle relative to a reference axis;

determine whether a condition associated with a recognition analysis is present at the coordinate; and

in response to the condition being present at the coordinate;

trigger capture of a second image at the coordinate with the depth sensor positioned at a second angle relative to the reference axis, the second angle being different than the first angle;

identify a second depth value corresponding to the coordinate of the object in the second image; and

calculate an accumulated value for the coordinate based on a difference between the first angle and the second angle and on a difference between the first and second depth values.

10. A storage medium as defined in claim 9, wherein the condition includes an indication that a person is detected at the coordinate at a distance from the depth sensor greater than a threshold distance associated with a person detector.

11. A storage medium as defined in claim 9, wherein the condition includes an indication that movement is detected at the coordinate at a distance from the depth sensor greater than a threshold distance associated with a movement detector.

12. A storage medium as defined in claim 9, wherein the condition includes an indication that a gesture is detected at the coordinate at a distance from the depth sensor greater than a threshold distance associated with a gesture detector.

13. A storage medium as defined in claim 9, wherein the instructions, when executed, cause the machine to identify a third depth value at the coordinate in a third image captured with the depth sensor positioned at a third angle relative to the reference axis, the third angle being different than the first and second angles.

14. A storage medium as defined in claim 13, wherein the instructions, when executed, cause the machine to calculate the accumulated value based on the first, second and third depth values.

15. An audience measurement device, comprising:

a recognizer to identify an object as likely being a person by analyzing data representative of an environment; and

a depth analyzer to, when a first depth value associated with a coordinate of the object captured by a depth sensor with the depth sensor oriented along a first axis is greater than a threshold distance from the depth sensor;

cause the depth sensor to capture a second depth value at the coordinate with the depth sensor positioned at a first tilt relative to the first axis; and

calculate an accumulated value for the coordinate based on (1) a comparison of the first depth value and the second depth value and (2) an angle of the first tilt;

at least one of the recognizer or the depth analyzer being implemented via a logic circuit.

16. An audience measurement device as defined in claim 15, wherein the angle is different than a baseline angle.

17. An audience measurement device as defined in claim 15, wherein the recognizer is to use the accumulated value to confirm that the object is a person.

18. An audience measurement device as defined in claim 15, wherein the depth analyzer is to actuate a tilt motor to move the depth sensor to the first tilt from the first axis.

19. An audience measurement device as defined in claim 15, wherein the angle is a particular number of degrees away from the first axis, the first axis extending away from the depth sensor.

20. An audience measurement device as defined in claim 15, wherein the depth sensor is to utilize a projected dot array, and a first dot of the dot array corresponds to the coordinate.

21. An apparatus, comprising:

a depth sensor to collect images of an environment, the depth sensor having a housing;

a tilt motor to tilt the housing of the depth sensor relative to a reference axis; and

a processor to;

determine a first depth value associated with a coordinate of a first image collected with the housing at a first angle relative to the reference axis;

instruct the tilt motor to move the housing to a second angle relative to the reference axis, the second angle being different from the first angle;

determine a second depth value associated with the coordinate in a second image collected by the depth sensor with the housing at the second angle; and

calculate a depth gradient for the coordinate based on the first depth value, the second depth value, and a difference between the first angle and the second angle.

22. A method, comprising:

analyzing, with a processor, a first depth value corresponding to a coordinate of an object of an image captured by a depth sensor, the first depth value having been captured with the depth sensor positioned at a first angle relative to a reference axis;

moving, with the processor, the depth sensor to a second angle relative to the reference axis, the second angle being different than the first angle;

triggering, with the processor, capture of a second depth value at the coordinate with the depth sensor positioned at the second angle; and

calculating, with the processor, a depth gradient for the coordinate based on the first depth value, the second depth value, and the second angle;

wherein the calculating of the depth gradient for the coordinate based on the first depth value, the second depth value, and the second angle includes;

calculating a first difference between the first depth and the second depth;

calculating a second difference between the first angle and the second angle; and

calculating a ratio of the first difference and the second difference.