Device and method for detecting non-visible content in a non-contact manner

• US 10,318,798 B2
• Filed: 07/10/2015
• Issued: 06/11/2019
• Est. Priority Date: 07/10/2015
• Status: Active Grant

• Current Assignee: BOOZ Allen Hamilton Holding Corporation
• Original Assignee: BOOZ Allen Hamilton Holding Corporation
• Inventors: Majumdar, Zigurts K., D'Angio, Paul C., Papazoglou, Michael A., Steinhardt, Allan, Hutchens, Christopher
• Primary Examiner(s): Rahaman, Mohammed S
• Assistant Examiner(s): Lee, Jimmy S
• Application Number:
  US14/796,343
• Publication Number:
  US 20170011259A1
• Time in Patent Office: 1,432 Days
• Field of Search: 348136
• CPC Class Codes: G01B 11/14 for measuring distance or clearance between spaced objects or spaced apertures G01B11/26 takes precedence; rangefinders G01C3/00
• CPC Class Codes: G06T 2207/30232 Surveillance
• CPC Class Codes: G06T 7/262 using transform domain methods, e.g. Fourier domain methods
• CPC Class Codes: G06V 10/145 Illumination specially adapted for pattern recognition, e.g. using gratings
• CPC Class Codes: G06V 20/52 Surveillance or monitoring of activities, e.g. for recognising suspicious objects recognising microscopic objects G06V20/69
• CPC Class Codes: G06V 2201/05 Recognition of patterns representing particular kinds of hidden objects, e.g. weapons, explosives, drugs
• CPC Class Codes: G06V 40/20 Movements or behaviour, e.g. gesture recognition recognition of facial expressions G06V40/16

Abstract

A method and device are provided for detecting non-visible content of an object in a non-contact manner. The device includes a light source configured to emit light toward a surface of an object over a period of time. The device also includes an optical sensing component configured to receive a pattern of light from the surface of the object, and to record the received pattern at plural points in time. In addition, the device includes a processing component configured to determine temporal changes in the pattern during the plural points in time, and to detect whether motion is present in the object based on determined temporal changes in the pattern, where the motion represents a frequency source of non-visible content in the object.

Claims

1. A device for detecting non-visible content of an object in a non-contact manner, the device comprising:

a light source configured to emit light toward a surface of an object over a period of time, wherein the light source includes a first laser configured to emit a first laser light toward a first surface of the object, and a second laser light source configured to emit a second laser light at a second surface of the object;

an optical sensing component configured to receive a pattern of light from the surface of the object, and to record the received pattern of light at plural points in time, wherein the received pattern of light includes a first interference pattern received from the first surface of the object based on the first laser light, and a second interference pattern received from the second surface of the object based on the second laser light; and

a processing component configured to determine temporal changes in the pattern of light during the plural points in time, and to detect whether motion is present in the object based on determined temporal changes in the pattern of light, the motion representing a frequency source of non-visible content in the object, wherein

the optical sensing component is configured to record a plurality of images of the received pattern at the plural points in time, and

the processing component is configured to calculate motion of corresponding identified segments in the plurality of images by determining which of the identified segments have at least a predetermined rate of change within the plural points in time.

2. The device according to claim 1, wherein the optical sensing component is configured to record, as the pattern, an image of an interference pattern of light received from the surface of the object.

3. The device according to claim 2, wherein the optical sensing component is configured to record the plurality of images of the interference pattern within an image frame at the plural points in time, and

wherein the processing component is configured to determine the temporal changes in the interference pattern by comparing the plurality of images and calculating changes in position of the interference pattern in the image frame between the plurality of images.

4. The device according to claim 3, wherein the processing component is configured to calculate changes in position of the interference pattern by overlapping at least two of the images and determining an amount of displacement of the overlapped images with respect to each other during the plural points in time.

5. The device according to claim 4, wherein the processing component is configured to determine the amount of displacement of the overlapped images based on respective intensities of the images and a relative motion of the respective intensities of the images with respect to each other during the plural points in time.

6. The device according to claim 5, wherein the processing component is configured to determine the amount of displacement of the overlapped images based on an amount of relative motion of the respective intensities with respect to Cartesian coordinates.

7. The device according to claim 3, wherein the processing component is configured to identify a plurality of segments in each of the images, respectively, and to calculate changes in position in the interference pattern by calculating changes in position of corresponding identified segments in the plurality of images.

8. The device according to claim 7, wherein the processing component is configured to associate each of the identified segments with position information indicating a respective position within the image frame in each corresponding image, and to determine whether the corresponding position information for at least one of the identified segments in a first one of the plurality of images changes with respect to the corresponding position information for the at least one of the identified segments in a second one of the plurality of images recorded subsequent to the first one of the plurality of images.

9. The device according to claim 8, wherein the processing component is configured to determine whether the corresponding position information for the at least one of the identified segments in the first one of the plurality of images changes with respect to a predetermined number of the plurality of images.

10. The device according to claim 8, wherein the position information includes Cartesian coordinates within the image frame for the corresponding identified segment.

11. The device according to claim 8, wherein the position information includes a measured position of the corresponding identified segment in relation to a known position of at least one other identified segment in the corresponding image.

12. The device according to claim 8, wherein the processing component is configured to calculate a frequency of change for each of the corresponding identified segments in the plurality of images.

13. The device according to claim 1, wherein the processing component is configured to detect non-visible contents of the object by determining which of the corresponding identified segments in the plurality of images have at least the predetermined rate of change during the plural points in time.

14. The device according to claim 13, wherein the processing component is configured to determine motion of the non-visible content of the object in a first direction and in a second direction transverse to the first direction.

15. The device according to claim 13, wherein the processing component is configured to detect a frequency of vibration in the non-visible content based on the determined rate of change of corresponding segments in the image frame within the plural points in time.

16. The device according to claim 1, wherein the optical sensing component includes a camera configured to record respective images of the pattern received from the first surface at the plural points in time.

17. The device according to claim 16, wherein the optical sensing component is configured to record a first image of the first interference pattern received from the first surface of the object based on the first laser light, to record a second image of the second interference pattern from the second surface of the object based on the second laser light, to record a plurality of the first images of the first interference pattern within a first image frame at the plural points in time, and to record a plurality of the second images of the second interference pattern within a second image frame at the plural points in time.

18. The device according to claim 17, wherein the processing component is configured to:

determine the temporal changes in the first interference pattern by comparing the plurality of first images and calculating changes in position of the first interference pattern in the first image frame between the plurality of first images;

determine the temporal changes in the second interference pattern by comparing the plurality of second images and calculating changes in position of the second interference pattern in the second image frame between the plurality of second images; and

determine whether the temporal changes in the first interference pattern are greater or less than the temporal changes in the second interference pattern.

19. The device according to claim 18, wherein the processing component is configured to identify a plurality of segments in each of the first and second images of the first and second interference patterns, respectively, and to identify segments in the first images which respectively correspond to segments in the second images, and

wherein the processing component is configured to detect temporal changes in the first and second interference patterns by calculating changes in position in the corresponding segments of the plurality of first and second images during the plural points in time.

20. The device according to claim 19, wherein the processing component is configured to:

record position information for each segment identified in each of the first and second images, respectively,

calculate changes in position of the corresponding segments by determining whether position information of the corresponding segments of the plurality of first and second images changes during the plural points in time, and

detect whether motion is present in the object based on the calculated changes in position of the corresponding segments of the plurality of first and second images.

21. The device according to claim 1, wherein the optical sensing component comprises a plurality of sensors each configured to detect a corresponding proximity of a plurality of segments of the pattern with respect to the sensors over the plural points in time, and

wherein the processing component is configured to determine temporal changes in the pattern during the plural points in time by determining whether each segment has a predetermined displacement between the recorded patterns.

22. The device according to claim 1, wherein the optical sensing component includes a light sensitive area configured to receive the pattern of light from the surface of the object,

wherein the optical sensing component is configured to output a signal proportional to changes in the pattern of light incident on the light sensitive area of the detector, and

wherein the processing component is configured to determine temporal changes in the pattern during the plural points in time based on the output signal of the optical sensing component.

23. The device according to claim 21, wherein the processing component is configured to determine temporal changes in the pattern by calculating an amount of change in the output signal of the optical sensing component.

24. The device according to claim 1, wherein the processing component is configured to detect motion within a predetermined frequency range.

25. A method for detecting non-visible content of an object in a non-contact manner, the method comprising:

emitting light from a light source toward a surface of an object over a period of time, wherein the light source includes a first laser configured to emit a first laser light toward a first surface of the object, and a second laser light source configured to emit a second laser light at a second surface of the object;

receiving, by an optical sensing component, a pattern of light from the surface of the object, and to record the received pattern of light at plural points in time, wherein the received pattern of light includes a first interference pattern received from the first surface of the object based on the first laser light, and a second interference pattern received from the second surface of the object based on the second laser light; and

determining, by a processor of a computer processing device, temporal changes in the pattern of light during the plural points in time; and

detecting, by the processor, whether motion is present in the object based on determined temporal changes in the pattern of light, the motion representing a frequency source of non-visible content in the object, wherein

the optical sensing component is configured to record a plurality of images of the received pattern at the plural points in time, and

the processing component is configured to calculate motion of corresponding identified segments in the plurality of images by determining which of the identified segments have at least a predetermined rate of change within the plural points in time.

26. The method according to claim 25, comprising:

recording, as the pattern, an image of an interference pattern of light received from the surface of the object; and

recording a plurality of the images of the interference pattern at the plural points in time.

27. The method according to claim 26, wherein the optical sensing component is configured to record the plurality of images of the interference pattern within an image frame at the plural points in time, and

wherein the processing component is configured to determine the temporal changes in the interference pattern by comparing the plurality of images and calculating changes in position of the interference pattern in the image frame between the plurality of images.

28. A non-transitory computer-readable recording medium having a computer program tangibly recorded thereon that, when executed by a processor of a computer processing device, causes the processor to carry out operations for detecting non- visible content of an object in a non-contact manner, the operations comprising:

emitting light toward a surface of an object over a period of time, wherein the light source includes a first laser configured to emit a first laser light toward a first surface of the object, and a second laser light source configured to emit a second laser light at a second surface of the object;

receiving a pattern of light from the surface of the object, and to record the received pattern of light at plural points in time, wherein the received pattern of light includes a first interference pattern received from the first surface of the object based on the first laser light, and a second interference pattern received from the second surface of the object based on the second laser light; and

determining temporal changes in the pattern of light during the plural points in time; and

detecting whether motion is present in the object based on determined temporal changes in the pattern of light, the motion representing a frequency source of non-visible content in the object, wherein

the optical sensing component is configured to record a plurality of images of the received pattern at the plural points in time, and

the processing component is configured to calculate motion of corresponding identified segments in the plurality of images by determining which of the identified segments have at least a predetermined rate of change within the plural points in time.

29. A device for detecting non-visible content of an object in a non-contact manner, the device comprising:

a light source configured to emit light toward a surface of an object over a period of time1 wherein the light source includes a first laser configured to emit a first laser light toward a first surface of the object, and a second laser light source configured to emit a second laser light at a second surface of the object;

an optical sensing component configured to receive a pattern of light from the surface of the object, and to record the received pattern of light at plural points in time, wherein the received pattern of light includes a first interference pattern received from the first surface of the object based on the first laser light, and a second interference pattern received from the second surface of the object based on the second laser light; and

a processing component configured to define the pattern recorded at at least one of the plural points in time as a reference pattern, to determine temporal changes in the pattern of light during the plural points in time by comparing the pattern of light during the plural points in time with the reference pattern, and to detect whether motion is present in the object when determined temporal changes in the pattern of light differ a predetermined amount the reference pattern, the motion representing non-visible content in the object, wherein

the optical sensing component is configured to record a plurality of images of the received pattern at the plural points in time, and

the processing component is configured to calculate motion of corresponding identified segments in the plurality of images by determining which of the identified segments have at least a predetermined rate of change within the plural points in time.