Spectral imaging method and system

Patent metadata

Field	Value
Publication number	US-10101206-B2
Application number	US-201515524827-A
Country	US
Kind code	B2
Filing date	Nov 5, 2015
Priority date	Nov 6, 2014
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

An imaging system and method are presents for use in reconstructing spectral data of an object. The imaging system comprises: an optical unit; a pixel array of a detector; and a data processor for receiving and processing image data indicative of light detected by the pixel array and generating reconstructed spectral data of the object being imaged. The optical unit is configured and operable for applying a predetermined coding to an input light field while creating an optical image thereof on a detection plane defined by the pixel array. Therefore, the image data is a function of the predetermined coding and a spectrum of the object to be determined.

First claim

The invention claimed is:

1. An imaging system for use in reconstructing spectral data of an object being imaged, the imaging system comprising: an optical unit; a detector having a pixel array configured and operable to detect light from the optical unit and generate image data indicative of the detected light; and a data processor configured and operable to receive and process the image data indicative of the light detected by the pixel array and generating reconstructed spectral data of the object being imaged by the optical unit; wherein the optical unit is configured and operable for applying predetermined angular coding to an input light field while creating an optical image thereof on an imaging plane defined by the pixel array, such that the image data is a function of a predetermined angular code and a spectrum of the object to be determined.

2. The system of claim 1 , wherein the optical unit comprises a coder assembly configured for applying said predetermined angular coding, and an imaging lens module, the imaging plane defined by the pixel array being located in the back focal plane of the lens module.

3. The system of claim 2 , wherein the coder assembly is accommodated in the optical path of the input light between the lens module and the imaging plane.

4. The system of claim 2 , wherein the coder assembly is accommodated upstream of the lens module with respect to input light propagation direction.

5. The system of claim 2 , wherein the coder assembly is operable in transmission or reflection mode.

6. The system of claim 2 , wherein the coder assembly comprises a dispersive unit, a given relative orientation of said lens module and a dispersive pattern of said dispersive unit defining given effective spectral transmission function of the optical unit, the predetermined angular code being defined by the effective spectral transmission function.

7. The system of claim 6 , comprising a controller associated with at least one of the dispersive unit and the lens module and configured and operable for modifying the effective spectral transmission function of the optical unit by carrying out at least one of the following: affecting the dispersive pattern of a tunable dispersive unit, affecting an angular position of the dispersive pattern with respect to an optical axis of the optical unit, varying a focal length of the lens module, and displacing the lens module.

8. The imaging system of claim 6 , wherein the dispersive unit comprises an etalon.

9. The imaging system of claim 6 , wherein the dispersive unit is tunable enabling controllable variation of the dispersive pattern thereof.

10. The imaging system of claim 6 , wherein the dispersive unit comprises a dispersive element having the predetermined dispersive pattern.

11. The system of claim 1 , wherein the detector is a monochromatic or color detector.

12. The system of claim 1 , wherein the angular coding applied to the input light field is defined by an effective spectral transmission function of the optical unit.

13. The system of claim 12 , further comprising a controller configured and operable to sequentially modify the effective spectral transmission function of the optical unit, to modify the angular coding applied to the input light field, the image data being thereby indicative of sequentially acquired frames with different angular coding of the input light field.

14. The imaging system of claim 12 , wherein the angular coding applied by the optical unit provides angular multiplexing of image data at the pixel array, such that the detected light intensity at the pixel corresponds to the spectral data of the image multiplexed with the effective transmittance function of the optical unit.

15. The imaging system claim 12 , wherein the processing unit is configured and operable to pre-process the image data corresponding to image of a region of interest within an acquired frame and identify the object whose spectral data is to be reconstructed, and utilize the effective spectral transmission function corresponding to acquisition of said frame for processing the image data of the identified object and reconstructing the object's spectrum.

16. The imaging system of claim 15 , wherein said pre-processing comprises applying at least one pattern recognition algorithm to the image data from the detector to identify the object having a substantially uniform spectral content.

17. The imaging system of claim 1 , wherein the optical unit is configured for imaging the object on at least N pixels of the pixel array, thereby allowing reconstruction of N spectral bands of the object being imaged.

18. The imaging system of claim 17 , wherein the optical unit includes a dispersive unit and a lens module including one or more lenses, a given relative orientation of said lens module and a dispersive pattern of said dispersive unit defining an effective spectral transmittance of the optical unit, the predetermined angular code being defined by the effective spectral transmission function.

19. A system for use in reconstructing spectral data of an object, the system comprising: an optical unit, an imaging lens module and a dispersive unit, a given relative orientation of said lens module and a dispersive pattern of said dispersive unit defining a given effective spectral transmission function of the optical unit, a predetermined angular code being defined by the effective spectral transmission function, such that said optical unit applies an angular coding, defined by the effective spectral transmission function, to an input light field while being imaged onto an imaging plane defined by a pixel array of a detector located in a back focal plane of the imaging lens module; a controller configured and operable to sequentially modify the effective spectral transmission function of the optical unit, to modify the angular coding applied to the input light field, such that image data generated by the detector is indicative of sequentially acquired frames with different angular coding of the input light field; and a data processor configured and operable to process the image data utilizing data indicative of the different angular coding applied in said sequentially acquired frames and generating reconstructed spectral data of the object being imaged.

20. A method for use in reconstructing spectral data of an object being imaged, the method comprising:
performing one or more optical imaging sessions, each optical imaging session comprising creating an image of an input light field originated in a region of interest in an imaging plane defined by a pixel array while applying to said input light field being imaged a predetermined angular coding, such that detected light intensity at the pixel corresponds to spectral data in the image created during the imaging session multiplexed with the predetermined angular coding; and
processing data indicative of the detected light intensity in each of said one or more imaging sessions, utilizing the predetermined angular coding, and determining the spectral data of the object.

Assignees

• Univ Ramot
• Ramot At Tel Avi Univ Ltd

Inventors

• Schleyen Ran
• Raz Ariel
• Mendlovic David

Classifications

• G01J2003/1243

  Pivoting IF or other position variation · CPC title

• G01J3/26 Primary

  using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters · CPC title

• G01J3/0229 Primary

  using masks, aperture plates, spatial light modulators or spatial filters, e.g. reflective filters · CPC title

• G01J3/2823 Primary

  Imaging spectrometer · CPC title