Method for operating an optical filter in multiple modes

• US 8,525,987 B2
• Filed: 09/12/2011
• Issued: 09/03/2013
• Est. Priority Date: 09/10/2010
• Status: Active Grant

• Current Assignee: Chemimage Corporation
• Original Assignee: Chemimage Corporation
• Inventors: Voigt, Thomas, Fuhrman, Michael, Shi, Lei
• Primary Examiner(s): Lauchman, Layla
• Application Number:
  US13/199,859
• Publication Number:
  US 20120062888A1
• Time in Patent Office: 722 Days
• Field of Search: 356/301, 356/300, 356/317, 356/326, 356/72, 356/73, 356/419, 382/133, 382/321
• US Class Current: 356/301
• CPC Class Codes: G01J 3/12 Generating the spectrum; Monochromators
• CPC Class Codes: G01J 3/1256 using acousto-optic tunable filter; acousto-optic elements or systems G02F1/11, G02F1/33
• CPC Class Codes: G01J 3/26 using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters

Abstract

A method for operating an optical filter in multiple modes. In one embodiment, an optical filter may be operated in a sensitivity mode to thereby generate a white light image representative of a region of interest. The optical filter may then be operated in a specificity mode to thereby generate a hyperspectral image representative of said region of interest. The white light image and the hyperspectral image may be fused to generate a hybrid image that provides morphological and hyperspectral data. The white light image and the hyperspectral image may be generated using a single detector, eliminating the need for image realignment.

Claims

1. A method for operating an optical system comprising:

operating an optical filter in a sensitivity mode to thereby generate at least one white light image representative of a region of interest;

operating said optical filter in a specificity mode to thereby generate at least one hyperspectral image representative of said region of interest; and

fusing said white light image and said hyperspectral image to thereby generate a hybrid image representative of said region of interest.

2. The method of claim 1 wherein said white light image and said hyperspectral image are obtained without realigning said optical system.

3. The method of claim 1 further comprising analyzing said white light image to thereby assess at least one morphological characteristic of an unknown object in said region of interest.

4. The method of claim 3 wherein said morphological characteristic comprises at least one of:

size of an unknown object, shape of an unknown object, color of an unknown object, and combinations thereof.

5. The method of claim 1 further comprising assessing said hyperspectral image to thereby target unknown object, identify an unknown object, and combinations thereof.

6. The method of claim 1 wherein said white light image and said hyperspectral image are generated using one detector.

7. The method of claim 6 wherein said detector is selected from the group consisting of:

an ICCD, a CCD, a CMOS detector, an InGaAs detector, an InSb detector, a MCT detector, and combinations thereof.

8. The method of claim 1 wherein said white light image is generated using a first detector and said hyperspectral image is generated using a second detector.

9. The method of claim 8 wherein at least one of said first detector and said second detector are selected from the group consisting of:

an ICCD, a CCD, a CMOS detector, an InGaAs detector, an InSb detector, a MCT detector, and combinations thereof.

10. The method of claim 8 wherein said detector comprises a focal plane array detector.

11. The method of claim 1 further comprising switching between operation in a sensitivity mode and operation in a specificity mode.

12. The method of claim 1 further comprising assessing at least one of said white light image and said hyperspectral image wherein said assessing is achieved by applying at least one chemometric technique.

13. The method of claim 12 wherein said chemometric technique is selected from the group consisting of:

principle components analysis, partial least squares discriminate analysis, cosine correlation analysis, Euclidian distance analysis, k-means clustering, multivariate curve resolution, band t. entropy method, mahalanobis distance, adaptive subspace detector, spectral mixture resolution, and combinations thereof.

14. The method of claim 1 wherein said operation in said sensitivity mode further comprises opening a plurality of bandpasses of said optical filter.

15. The method of claim 1 wherein said operation in said specificity mode further comprises opening one bandpass of said optical filter.

16. The method of claim 1 wherein said optical filter comprises at least one of:

a liquid crystal tunable filter, a multi-conjugate liquid crystal tunable filter, an acousto-optical tunable filter, a Lyot liquid crystal tunable filter, an Evans split-element liquid crystal tunable filter, a Solc liquid crystal tunable filter, a ferroelectric liquid crystal tunable filter, a Fabry Perot liquid crystal tunable filter, and combinations thereof.

17. The method of claim 1 wherein said hyperspectral image comprises at least one of:

a hyperspectral Raman image, a hyperspectral infrared image, a hyperspectral fluorescence image, a hyperspectral visible image, a LIBS hyperspectral image, an ultraviolet hyperspectral image, and combinations thereof.

18. The method of claim 17 wherein said hyperspectral infrared image comprises at least one of:

a SWIR hyperspectral image, a NIR hyperspectral image, a MWIR hyperspectral image, a LWIR hyperspectral image, and combinations thereof.

19. A method for operating an optical system comprising:

operating an optical filter in a sensitivity mode to thereby generate at least one white light image representative of a region of interest, wherein said sensitivity mode comprises opening a plurality of bandpasses of said optical filter;

operating an optical filter in a specificity mode to thereby generate at least one hyperspectral image representative of said region of interest, wherein said specificity mode comprises opening one bandpass of said optical filter, and

wherein said white light image and said hyperspectral image are obtained without realigning said optical system; and

fusing said white light image and said hyperspectral image to thereby generate a hybrid image representative of said region of interest.