Spectral imaging system for remote and noninvasive detection of target substances using spectral filter arrays and image capture arrays
An approach to noninvasively and remotely detect the presence, location, and/or quantity of a target substance in a scene via a spectral imaging system comprising a spectral filter array and image capture array. For a chosen target substance, a spectral filter array is provided that is sensitive to selected wavelengths characterizing the electromagnetic spectrum of the target substance. Elements of the image capture array are optically aligned with elements of the spectral filter array to simultaneously capture spectrally filtered images. These filtered images identify the spectrum of the target substance. Program instructions analyze the acquired images to compute information about the target substance throughout the scene. A color-coded output image may be displayed on a smartphone or computing device to indicate spatial and quantitative information about the detected target substance. The system desirably includes a library of interchangeable spectral filter arrays, each sensitive to one or more target substances.
1. A method of using a spectral imaging system to capture image information to detect one or more target substances in a scene, comprising the steps of:
a) providing an image capture array comprising a plurality of image capturing elements;
b) providing a plurality of interchangeable, spectral filter arrays that are interchangeably selectable to be optically aligned with the image capture array, and wherein each spectral filter array comprises a plurality of spectral filter elements and a filter array identifier;
c) selecting and optically aligning a spectral filter array with the image capture array to provide a plurality of wavelength channels that independently capture spectrally filtered images;
d) using the filter array identifier to automatically identify the selected spectral filter array;
e) automatically selecting one or more algorithms pre-associated with the identified spectral filter array from a library of algorithms;
f) using the wavelength channels to capture spectrally filtered image information of the scene; and
g) using the captured spectrally filtered image information and the automatically selected one or more algorithms to determine whether the one or more target substances are detected in the scene.
2. The method of claim 1 , wherein step e) comprises using an identifying characteristic on a filter array to select an associated algorithm.
3. The method of claim 1 , wherein the plurality of interchangeable, spectral filter arrays comprises a plurality of spectral filter cards, wherein each spectral filter card comprises a filter element array comprising a plurality of filter elements.
4. The method of claim 1 , wherein the filter array identifier comprises an RFID tag.
5. The method of claim 1 , wherein the filter array identifier is electronically readable.
6. The method of claim 1 , wherein step e) comprises using an orientation of a filter array in the system to select a pre-associated algorithm.
7. The method of claim 1 , wherein step e) further comprises automatically selecting a user interface associated with the identified spectral filter array that is used to detect a target substance in the scene.
8. The method of claim 1 , wherein an algorithm that is pre-associated with an identified spectral filter array analyzes captured image information to determine which portion(s) of the image information, if any, have spectral characteristics that match the target substance.
9. The method of claim 1 , wherein each wavelength channel includes an image capturing element of the image capture array and a filter element of the array that is optically aligned with the image capturing element.
10. The method of claim 1 , further comprising the step of providing an output indicative of whether the one or more target substances are detected in the scene.
11. The method of claim 10 , wherein the output indicates a location of the one or more target substances in the scene.