Method and apparatus for remote sensing and comparing utilizing radiation speckle

• US 9,582,883 B2
• Filed: 05/19/2014
• Issued: 02/28/2017
• Est. Priority Date: 06/16/2006
• Status: Active Grant

• Current Assignee: Lyle G. Shirley
• Original Assignee: Lyle G. Shirley
• Inventors: Shirley, Lyle G.
• Primary Examiner(s): Chowdhury, Tarifur
• Assistant Examiner(s): Cook, Jonathon
• Application Number:
  US14/281,255
• Publication Number:
  US 20140321734A1
• Time in Patent Office: 1,016 Days
• Field of Search: 356/511, 356/512
• US Class Current: 1/1
• CPC Class Codes: A61B 2576/00 Medical imaging apparatus involving image processing or analysis A61B1/00009, A61B6/52 and A61B8/52 take precedence; image processing per se G06T; details of algorithms for analysing medical images G06T7/0012
• CPC Class Codes: A61B 5/0077 Devices for viewing the surface of the body, e.g. camera, magnifying lens
• CPC Class Codes: A61B 5/117 Identification of persons methods or arrangements for recognising patterns, e.g. fingerprints, G06F18/00, G06V40/00; identification of persons by analysing their voice or speech G10L17/00
• 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: G01B 11/2441 using interferometry
• CPC Class Codes: G01B 9/02004 using frequency scans
• CPC Class Codes: G01B 9/02005 using discrete frequency stepping or switching
• CPC Class Codes: G01B 9/02069 Synchronization of light source or manipulator and detector
• CPC Class Codes: G01B 9/02083 characterised by particular signal processing and presentation
• CPC Class Codes: G01B 9/02094 Speckle interferometers, i.e. for detecting changes in speckle pattern
• CPC Class Codes: G01B 9/02096 detecting a contour or curvature
• CPC Class Codes: G06F 18/253 of extracted features
• CPC Class Codes: G06F 21/32 using biometric data, e.g. fingerprints, iris scans or voiceprints
• CPC Class Codes: G06T 2207/10152 Varying illumination
• CPC Class Codes: G06T 7/521 from laser ranging, e.g. using interferometry; from the projection of structured light
• CPC Class Codes: G06T 7/55 from multiple images
• CPC Class Codes: G06V 10/143 Sensing or illuminating at different wavelengths
• CPC Class Codes: G06V 10/806 of extracted features
• CPC Class Codes: G16H 30/40 for processing medical images, e.g. editing

Abstract

Disclosed are systems and methods to extract information about the size and shape of an object by observing variations of the radiation pattern caused by illuminating the object with coherent radiation sources and changing the wavelengths of the source. Sensing and image-reconstruction systems and methods are described for recovering the image of an object utilizing projected and transparent reference points and radiation sources such as tunable lasers. Sensing and image-reconstruction systems and methods are also described for rapid sensing of such radiation patterns. A computational system and method is also described for sensing and reconstructing the image from its autocorrelation. This computational approach uses the fact that the autocorrelation is the weighted sum of shifted copies of an image, where the shifts are obtained by sequentially placing each individual scattering cell of the object at the origin of the autocorrelation space.

Claims

1. An imaging apparatus, said imaging apparatus comprising:

at least one source of coherent radiation outputting a plurality of wavelengths illuminating an object creating a plurality of speckle patterns whereby each speckle pattern of said plurality of speckle patterns corresponds to one of said plurality of wavelengths;

at least one sensor at a location relative to said object to determine a speckle pattern intensity of said speckle pattern for each of said plurality of wavelengths;

a processor receiving information from said at least one sensor, said processor having means for constructing at least one autocorrelation of said object from said speckle pattern intensity of said speckle pattern;

said processor further comprising means to compare at least one of said at least one autocorrelation; and

said processor further comprising means to compare said at least one autocorrelation of said object to a second autocorrelation.

2. The imaging apparatus of claim 1 wherein said at least one autocorrelation is obtained from a measurement of said object at a first time and said second autocorrelation is obtained from a measurement of said object at a second time.

3. The imaging apparatus of claim 1 wherein said processor further comprises means for relating a change between said object at a first time and a second time to said comparison of said at least one autocorrelation and said second autocorrelation.

4. The imaging apparatus of claim 1 wherein said second autocorrelation comprises an autocorrelation of a physical feature of an object.

5. The imaging apparatus of claim 1 wherein:

said speckle pattern intensity varies spatially; and

said speckle pattern intensity at an observation point can be represented by a function I(x, y, z;

ν

).

6. An imaging apparatus, said imaging apparatus comprising:

at least one source of coherent radiation outputting a plurality of wavelengths;

illuminating an object creating a plurality of speckle patterns each corresponding to one of the said plurality of wavelengths;

at least one sensor at a location relative to said object to determine a speckle pattern intensity of a speckle pattern from said plurality of speckle patterns for each of said plurality of wavelengths;

a processor receiving information from at least one sensor, said processor having means for constructing at least one autocorrelation of said object from said speckle pattern intensity of said speckle pattern;

said processor further comprising means to compare at least one of said at least one autocorrelation;

wherein said processor further comprises means to compare said at least one autocorrelation of said object to a second autocorrelation;

wherein said second autocorrelation comprises an autocorrelation of a physical feature of an object; and

wherein said processor further comprises means for verifying that said physical feature of an object is not contained in said object by comparing a support of said at least one autocorrelation and said second autocorrelation.

7. The imaging apparatus of claim 6 wherein said at least one autocorrelation is obtained from a measurement of said object at a first time and said second autocorrelation is obtained from a measurement of said object at a second time.

8. The imaging apparatus of claim 6 wherein said physical feature of an object comprises a CAD model or a mathematical model of said physical feature of said object.

9. An imaging apparatus, said imaging apparatus comprising:

at least one source of coherent radiation outputting a plurality of wavelengths;

illuminating an object creating a plurality of speckle patterns each corresponding to one of the said plurality of wavelengths;

at least one sensor at a location relative to said object to determine a speckle pattern intensity of a speckle pattern from said plurality of speckle patterns for each of said plurality of wavelengths;

a processor receiving information from at least one sensor, said processor having means for constructing at least one autocorrelation of said object from said speckle pattern intensity of said speckle pattern;

said processor further comprising means to compare at least one of said at least one autocorrelation;

more than one autocorrelation of said object; and

said processor further comprising means to rotate and compare one autocorrelation of said object relative to at least one other autocorrelation of said object to construct a representation of said object.

10. The imaging apparatus of claim 9 wherein said at least one autocorrelation is obtained from a measurement of said object at a first time and said at least one other autocorrelation is obtained from a measurement of said object at a second time.

11. The imaging apparatus of claim 9 wherein said means to rotate and compare one autocorrelation of said object relative to at least one other autocorrelation of said object to construct a representation of said object includes the step of taking a difference between rotationally aligned said at least one autocorrelation and said at least one other autocorrelation.

12. An imaging apparatus comprising:

at least one source of coherent radiation outputting a plurality of wavelengths illuminating an object creating a plurality of speckle patterns each corresponding to one of said plurality of wavelengths;

at least one sensor at a location relative to said object to determine a speckle pattern intensity of a speckle pattern for each of said plurality of wavelengths for each of said plurality of wavelengths;

said source of coherent radiation rapidly outputting said plurality of wavelengths;

means to associate the outputting of each of said plurality of wavelengths from said coherent radiation source with a time of receipt of at least one spatial component of said speckle pattern intensity of said speckle pattern at said at least one sensor whereby said time of receipt of said at least one spatial component of said speckle pattern intensity associates said at least one spatial component of said speckle pattern intensity to one of said plurality of wavelengths;

said means to associate the outputting of each of said plurality of wavelengths from said at least one source of coherent radiation with said time of receipt of said at least one spatial component of said speckle pattern intensity at said at least one sensor comprises a timing means to correlate said outputting of said plurality of wavelengths and said receipt of said at least one spatial component of said speckle pattern intensity;

said source of coherent radiation rapidly outputting said plurality of wavelengths comprises said source of coherent radiation outputting said plurality of wavelengths whereby one of each of said plurality of wavelengths is outputted within a timing cycle of said sensor; and

a processor receiving information from said at least one sensor, said processor having means for constructing at least one autocorrelation of said object from said speckle pattern intensity.

13. The imaging apparatus of claim 12 wherein said timing means further comprises a timing clock communicating at least one correlated timing signal with said sensor and said coherent radiation source.

14. The imaging apparatus of claim 13 wherein said sensor is a Geiger-mode avalanche photodiode array.

15. The imaging apparatus of claim 13 wherein said correlated timing signal comprises a photon arrival time for at least one pixel of said sensor.

16. The imaging apparatus of claim 12 wherein said rapidly outputting of said plurality of wavelengths comprises a repetitive frequency chirp whereby a count can be made of a number of photons arriving within at least one time interval associated with a time bin of a repetitive waveform for at least one pixel of said sensor.

17. The imaging apparatus of claim 16 wherein said repetitive frequency chirp comprises alternating up-chirps and down-chirps.

18. The imaging apparatus of claim 15 wherein a data cube is formed by accumulating a count of number of photons arriving within at least one time interval associated with a time bin of a repetitive waveform for said at least one pixel of said sensor.

19. The imaging apparatus of claim 12 further comprising at least one pixel on said at least one sensor whereby said plurality of speckle patterns can be received by said pixel on said at least one sensor within a frame time of said at least one sensor.

20. The imaging apparatus of claim 12 further comprising a plurality of pixels on said at least one sensor whereby said plurality of speckle patterns can be received by said plurality of pixels on said at least one sensor within a frame time of said at least one sensor.