Spectral imaging method and system

• US 10,605,660 B2
• Filed: 07/28/2016
• Issued: 03/31/2020
• Est. Priority Date: 07/30/2015
• Status: Active Grant

• Current Assignee: Technology Innovation Momentum Fund (Israel) Limited
• Original Assignee: Technology Innovation Momentum Fund (Israel) Limited
• Inventors: Raz, Ariel, Mendlovic, David
• Primary Examiner(s): Lyons, Michael A
• Application Number:
  US15/746,824
• Publication Number:
  US 20180209850A1
• Time in Patent Office: 1,342 Days
• CPC Class Codes: G01J 2003/1247 Tuning
• CPC Class Codes: G01J 2003/2813 2D-array
• CPC Class Codes: G01J 2003/2826 Multispectral imaging, e.g. filter imaging
• CPC Class Codes: G01J 3/0264 Electrical interface; User interface
• CPC Class Codes: G01J 3/26 using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• CPC Class Codes: G01J 3/2823 Imaging spectrometer
• CPC Class Codes: G01J 3/502 using a dispersive element, e.g. grating, prism
• CPC Class Codes: G16H 30/20 for handling medical images, e.g. DICOM, HL7 or PACS
• CPC Class Codes: G16H 40/63 for local operation

Abstract

A hyperspectral imaging system and method are presented for use in reconstruction of spectral data of an object. The system comprises: a pixel matrix of a detector; a tunable dispersive unit in front of the pixel matrix; and a control system. The control system comprises: a controller for tuning the dispersive unit during n image acquisition sessions to provide n different partially overlapping spectral transmission profiles of the dispersive unit; and a control unit which is in data communication with the detector and is configured and operable for processing n image data pieces generated by the pixel matrix in said n image acquisition sessions respectively, each being indicative of a spectral image detected by the pixel matrix and corresponding to the different spectral transmission profile of the dispersive unit, and determining the reconstructed spectral data of the object.

Claims

1. A hyperspectral imaging system for use in reconstructing spectral data of an object, the system comprising:

a pixel matrix of a detector;

a dispersive unit in front of the pixel matrix, wherein the dispersive unit comprises a spectral filter; and

a control system comprising;

a controller for tuning the dispersive unit during n image acquisition sessions to provide n different spectral transmission profiles of the dispersive unit;

wherein n is an integer that exceeds one;

wherein the different spectral transmission profiles partially overlap; and

a control unit in data communication with the detector and being

configured and operable for processing n image data pieces generated by the pixel matrix in said n image acquisition sessions respectively, each being indicative of a spectral image detected by the pixel matrix and corresponding to the different spectral transmission profiles of the dispersive unit, and determining, based on the different spectral transmission profiles of the dispersive unit, a reconstructed spectral data of the object.

2. The imaging system of claim 1, wherein the spectral filter is an etalon configured with a wide spectral range.

3. The imaging system of claim 2, wherein the dispersive unit is configured as a clear aperture Fabry-Perot etalon.

4. The imaging system of claim 3, wherein the imaging system is being configured and operable as a dual-purpose imaging system, selectively operating the dispersive unit in a standard color imaging mode during which a single image acquisitions is performed and in a hyperspectral imaging mode during which the n image acquisition sessions are performed.

5. The imaging system of claim 2, wherein the control unit is configured and operable for processing the n image data pieces and determining the reconstructed spectral data of the object, utilizing the following relation between the n image data pieces h, . . . TN and n spectral bands R(A−

1) . . . R(AN) of the object;

6. The imaging system of claim 1, wherein each one of the n different transmission profiles of the dispersive unit is a function of wavelengths and a tunable parameter of the dispersive unit.

7. The imaging system of claim 6, wherein the plurality of the image data pieces is a function of the plurality of the n different transmission profiles of the dispersive unit and the reconstructed spectral data of the object.

8. The imaging system of claim 1, wherein during each image acquisition session of then image acquisition sessions, a passage of light through the dispersive unit provides wavelength multiplexing of image data at the pixel matrix, such that for each pixel of the pixel matrix a detected light intensity at the pixel corresponds to the spectral data of the image multiplexed with a transmittance function of the dispersive unit applied during the image acquisition session.

9. The imaging system of claim 1, wherein the detector is configured as a monochromatic or color detector.

10. A hyperspectral imaging method for use in reconstructing spectral data of an object, the method comprising:

sequentially acquiring a plurality of n image frames, by performing n imaging sessions of the object onto a pixel matrix of a detector, while sequentially applying, by a dispersive unit that comprises a spectral filter, to light being imaged on the dispersive unit, n different dispersion profiles that are different from one another and partially overlap, thereby obtaining n image data pieces indicative of n different spectral images of the object, wherein n is an integer that exceeds one; and

processing said n image data pieces utilizing data about the n different n dispersion profiles, and reconstructing n spectral bands of the object being imaged.

11. The method of claim 10, wherein said applying of then different dispersion profiles comprises interacting the light with a dispersive pattern.

12. The method of claim 10, wherein data indicative of the n image data pieces is a function of the n different dispersive profiles and a spectrum of the object.

13. The method of claim 10 wherein each one of different dispersive profiles of the dispersive unit is a function of wavelengths and a tunable parameter of the dispersive unit.

14. The method of claim 10 wherein the determining of the reconstructed spectral data of the object, comprises utilizing the following relation between the n image data pieces h, . . . TN and n spectral bands R(A−

1) . . . R(AN) of the object;

15. A control unit for reconstructing spectral data of an object,

the control unit being configured for receiving input data comprising data indicative of n image data pieces corresponding to n spectral images obtained by a pixel matrix, each of said n spectral images being coded by a dispersive unit that comprises a tunable filter while applying a different dispersive profile out of n different dispersive profiles, wherein n is an integer that exceeds one;

and

wherein the control unit comprising an analyzer configured and operable for utilizing data indicative of the n different dispersive profiles in association with the respective n image data pieces and determining the spectral data of the object.

16. The control unit of claim 15, configured and operable for processing the n image data pieces and determining the reconstructed spectral data of the object, utilizing the following relation between the n image data pieces ‘

1, . . . TN and n spectral bands

R(li.1) . . . R(li.N) of the object;