SPATIAL RESOLUTION ENHANCEMENT IN HYPERSPECTRAL IMAGING

• US 20150015692A1
• Filed: 01/30/2013
• Published: 01/15/2015
• Est. Priority Date: 01/30/2012
• Status: Active Grant

• Current Assignee: Healthy.io, Ltd.
• Original Assignee: Scanadu Incorporated
• Inventors: Smart, Anthony
• Granted Patent: US 9,818,193 B2
• Time in Patent Office: Days
• US Class Current: 348/77
• CPC Class Codes: G01J 3/2823 Imaging spectrometer
• CPC Class Codes: G01J 3/36 Investigating two or more bands of a spectrum by separate detectors
• CPC Class Codes: G01J 3/51 using colour filters
• CPC Class Codes: G06T 2207/10152 Varying illumination
• CPC Class Codes: G06T 2207/30088 Skin; Dermal
• CPC Class Codes: G06T 7/337 involving reference images or patches
• CPC Class Codes: H04N 23/80 Camera processing pipelines; Components thereof

Abstract

In a hyperspectral imaging system and method, a pixilated imaging sensor array receives light reflected from, transmitted through, or scattered by a target scene. Images of the target scene are acquired at a number of times and these images are processed to generate hyperspectral data for each pixel of the imaging sensor array based on data for the pixel included in each of the acquired images. This processing can include spatially aligning two or more of the images that were spatially shifted with respect to each other when acquired based on at least one common image feature in the images.

Claims

1. A hyperspectral imaging system comprising:

an imaging sensor array including an array of pixels configured for outputting electrical signals in response to receiving light reflected from, transmitted through, or scattered by a target scene;

an array of light filters configured for filtering the light reaching the pixels of the imaging sensor; and

a controller adapted to;

acquire into a memory of the controller from the imaging sensor array a plurality of images of the target scene during movement or dithering of the combination of the imaging sensor array and the array of light filters, wherein said plurality of images as acquired are spatially shifted with respect to each other; and

process the plurality of acquired images in the memory of the controller to spatially align said plurality of images based on at least one common image feature in said plurality of images.

2. The hyperspectral imaging system of claim 1, wherein each image includes the electrical signals output by the array of pixels of the imaging sensor array at the same time or substantially the same time.

3. The hyperspectral imaging system of claim 1, wherein the array of light filters includes light filters that are configured to filter different center, peak transmission wavelengths of light.

4. The hyperspectral imaging system of claim 3, wherein adjacent light filters of at least a portion of the array of light filters are configured to filter different center, peak transmission wavelengths of light.

5. The hyperspectral imaging system of claim 1, wherein:

the array of light filters includes a n² array of light filters, where n is a positive integer that is >

1; and

the light filters of the n² array of light filters are configured to filter different center, peak transmission wavelengths of light.

6. The hyperspectral imaging system of claim 5, wherein sums of optical power transmitted by the light filters of each row and column of the array of light filters are the same or substantially the same.

7. The hyperspectral imaging system of claim 1, further including a device for moving or dithering the combination of the imaging sensor array and the array of light filters.

8. The hyperspectral imaging system of claim 7, further including the controller adapted to synchronize said movement or dithering and said acquiring of images such that the plurality of images as acquired are spatially shifted with respect to each other.

9. A hyperspectral imaging system comprising:

a plurality of illumination sources, each having a different spectrum, for outputting light for reflection by, transmission through, or scattering by a target scene;

an imaging sensor array including an array of pixels configured for outputting electrical signals in response to receiving the light reflected from, transmitted through, or scattered by the target scene; and

a controller adapted to;

acquire into a memory of the controller from the imaging sensor array a first image of the target scene illuminated by a first one of the plurality of illumination sources;

acquire into the memory of the controller from the imaging sensor array a second image of the target scene illuminated by a second one of the plurality of illumination source; and

generate hyperspectral data for each pixel of the imaging sensor array based on data for said pixel included the first and second acquired images.

10. The hyperspectral imaging system of claim 9, wherein each image includes the electrical signals output by the array of pixels of the imaging sensor array at the same time or substantially the same time.

11. The hyperspectral imaging system of claim 9, wherein the first and second illumination sources have either overlapping or non-overlapping spectra.

12. The hyperspectral imaging system of claim 9, wherein at least one of the illumination sources is a monochromatic illumination source.

13. The hyperspectral imaging system of claim 9, wherein at least one of the illumination sources is a white illumination source.

14. A method of hyperspectral imaging using an imaging sensor array including an array of pixels configured for outputting electrical signals in response to receiving light reflected from, transmitted through, or scattered by a target scene and an array of light filters configured for filtering the light reaching the pixels of the imaging sensor, the method comprising:

(a) acquiring from the imaging sensor array a plurality of images of the target scene during movement or dithering of the combination of the imaging sensor array and the array of light filters, wherein said plurality of images as acquired are spatially shifted with respect to each other;

(b) processing the plurality of acquired images to spatially align said plurality of images based on at least one common image feature in said plurality of images; and

(c) following step (b), generating hyperspectral data based on the aligned images.

15. The method of claim 14, wherein each acquired image includes the electrical signals output by the array of pixels of the imaging sensor array at the same time or substantially the same time.

16. The method of claim 14, wherein:

the array of light filters comprises plural rows and plural columns of light filters; and

adjacent light filters of at least a portion of the array of light filters are configured to filter different center, peak transmission wavelengths of light.

17. The method of claim 14, wherein sums of optical power transmitted by the light filters of each row and column are the same or substantially the same.

18. A method of hyperspectral imaging using a plurality of illumination sources, each having a different spectrum, for outputting light for reflection by, transmission through, or scattering by a target scene and an imaging sensor array including an array of pixels configured for outputting electrical signals in response to receiving the light reflected from, transmitted through, or scattered by the target scene, the method comprising:

acquiring a first image of the target scene illuminated only by a first one of the plurality of illumination sources;

acquiring a second image of the target scene illuminated only by a second one of the plurality of illumination source; and

generating hyperspectral data for each pixel of the imaging sensor array based on data for said pixel in the first and second acquired images.

19. The method of claim 18, wherein each image includes the electrical signals output by the array of pixels of the imaging sensor array at the same time or substantially the same time.

20. The method of claim 18, wherein the first and second illumination sources have either overlapping or non-overlapping spectra.

21. The method of claim 18, wherein at least one of the illumination sources is a monochromatic illumination source.

22. The method of claim 18, wherein at least one of the illumination sources is a white illumination source.