Method for generating hyperspectral images, hyperspectral imaging system, and optical dispersion device

Abstract

A hyperspectral imaging (HSI) system for generating hyperspectral images is provided. The HSI system includes a mask, an image sensor, and an optical dispersion device. The optical dispersion device is configured to relay a masked image from the mask to the image sensor and includes a first optical element and multiple second optical elements. The first optical element has a first principal axis, and the second optical elements share a second principal axis, where the first principal axis is positioned relative to the second principal axis with an offset, and the offset includes at least one of a parallel displacement and an angular deviation.

Description

METHOD FOR GENERATING HYPERSPECTRAL IMAGES, HYPERSPECTRAL IMAGING SYSTEM, AND OPTICAL DISPERSION DEVICEFIELD

[0001] The present disclosure generally relates to an imaging technology and, more particularly, to a method for generating hyperspectral images, and a hyperspectral imaging system, and an optical dispersion device.BACKGROUND

[0002] In hyperspectral imaging (HSI) systems, dispersion devices such as prisms and optical diffraction elements are used to introduce dispersion for analyzing the spectral information in the reflected or transmitted light of an object. The dispersion capability of these devices directly affects the spectral resolution capability of the system. For example, when processing spectra in the wavelength range of 400 to 900 nanometers, more sensing pixels can obtain richer spectral information. Generally, increasing the length of the system or the number of dispersion elements (e.g., adding more prisms or optical diffraction elements) is a common method to improve spectral resolution.

[0003] Increasing the number of prisms has relatively high processing costs. Additionally, to achieve greater dispersion capability, the angle of the prisms needs to be increased, which will lead to an increase in the system size and corresponding costs. Furthermore, combining prisms made of different materials to produce dispersion can enhance dispersion capability, but increasing the refractive index differences between these materials can affect the Modulation Transfer Function (MTF) of the lens, causing different wavelengths of light to interfere with each other upon reaching the sensor, thereby reducing the system's resolution.

[0004] On the other hand, increasing the number of optical diffraction elements introduces many issues. For example, adding more diffraction elements introduces problems related to stray light, which affects the system's accuracy. Factors such as reflection, scattering, and multiple-order diffraction of the diffraction elements can impact the system's efficiency. The stray light caused by increasing the number of diffraction elements can result in a decrease in the signal-to-noise ratio.SUMMARY

[0005] In view of the above, the present disclosure provides a method for generating hyperspectral images, a hyperspectral imaging system, and an optical dispersion device, that can effectively increase the dispersion to improve the spectral resolution while maintaining the cost.

[0006] A first aspect of the present disclosure provides an optical dispersion device for relaying an image to an image sensor. The optical dispersion device includes a first optical element having a first principal axis; and a plurality of second optical elements sharing a second principal axis. The first principal axis is positioned relative to the second principal axis with an offset, and the offset includes at least one of a parallel displacement and an angular deviation.

[0007] In an implementation of the first aspect, the image is relayed to the image sensor through an optical path, the second principal axis aligns with an optical axis of the optical path, and the offset exists between the first principal axis and the optical axis.

[0008] In another implementation of the first aspect, the angular deviation comprises an angle rotated along the second principal axis.

[0009] In yet another implementation of the first aspect, the angular deviation comprises an angle rotated along a first axis, and the first axis is perpendicular to the second principal axis.

[0010] In yet another implementation of the first aspect, the optical dispersion device further includes an adjustment element that is configured to adjust the offset.

[0011] In yet another implementation of the first aspect, the adjustment element is further configured to: increase the parallel displacement to increase spectral dispersion of the image; and decrease the parallel displacement to reduce the spectral dispersion of the image.

[0012] In yet another implementation of the first aspect, the adjustment element is further configured to: increase the angular deviation to increase spectral dispersion of the image; and decrease the angular deviation to reduce the spectral dispersion of the image.

[0013] In yet another implementation of the first aspect, the first optical element and the plurality of second optical elements include a zoom lens, and the zoom lens is configured to adjust a magnification of the optical dispersion device.

[0014] In yet another implementation of the first aspect, the first optical element includes at least one of a lens, a prism, a grating, and a planar mirror.

[0015] In yet another implementation of the first aspect, the plurality of second optical elements includes at least one of a lens, a prism, a grating, and a planar mirror.

[0016] A second aspect of the present disclosure, a hyperspectral imaging system is provided. The hyperspectral imaging system includes a mask, a first image sensor, and the optical dispersiondevice provided in the first aspect of the present disclosure. The optical dispersion device is configured to relay a mask image from the mask to the first image sensor.

[0017] In an implementation of the second aspect, the hyperspectral imaging system further includes a processor, which is coupled to the first image sensor and configured to perform an analysis based on a first output image from the first image sensor, a configuration of the optical dispersion device, and a pattern of the mask.

[0018] In another implementation of the second aspect, the hyperspectral imaging system further includes an objective lens, a second image sensor coupled to the processor, and a beam splitter. The beam splitter is configured to split an input image from the objective lens to the mask and the second image sensor. The processor is further configured to perform the analysis based on the first output image from the first image sensor, a second output image from the second image sensor, the configuration of the optical dispersion device, and the pattern of the mask.

[0019] In yet another implementation of the second aspect, the configuration of the optical dispersion device includes the offset.

[0020] A third aspect of the present disclosure provides a method for generating a hyperspectral image. The method includes providing a mask; providing the optical dispersion device provided in the first aspect of the present disclosure; converting an input image into a mask image through the mask; and relaying the mask image to an image sensor through the optical dispersion device.

[0021] A fourth aspect of the present disclosure provides an optical dispersion device for relaying an image to an image sensor. The optical dispersion device includes a first optical element having a first principal axis, multiple second optical elements sharing a second principal axis, and an adjustment element. The adjustment element is configured to adjust an offset between the first principal axis and the second principal axis. The offset includes at least one of a parallel displacement and an angular deviation.BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1 is a diagram illustrating a hyperspectral imaging system in accordance with an example implementation of the present disclosure.

[0023] FIG. 2 is a diagram illustrating an optical dispersion device in accordance with an example implementation of the present disclosure.

[0024] FIG. 3 is a diagram illustrating an optical dispersion device in accordance with an example implementation of the present disclosure.

[0025] FIG. 4A and FIG. 4B are diagrams illustrating two different dispersion directions in accordance with an example implementation of the present disclosure.

[0026] FIG. 5A and FIG. 5B are diagrams illustrating an image analysis in accordance with an example implementation of the present disclosure.

[0027] FIG. 6 is a flowchart for generating a hyperspectral image in accordance with an example implementation of the present disclosure.DETAILED DESCRIPTION

[0028] The following will refer to the relevant drawings to describe implementations of a method for generating hyperspectral images, a hyperspectral imaging system, and an optical dispersion device in the present disclosure, in which the same components will be identified by the same reference symbols.

[0029] The following description includes specific information regarding the exemplary implementations of the present disclosure. The accompanying detailed description and drawings of the present disclosure are intended to illustrate the exemplary implementations only. However, the present disclosure is not limited to these exemplary implementations. Those skilled in the art will appreciate that various modifications and alternative implementations of the present disclosure are possible. In addition, the drawings and examples in the present disclosure are generally not drawn to scale and do not correspond to actual relative sizes.

[0030] The term “couple” is defined as a connection, whether direct or indirect, through an intermediate component, and is not necessarily limited to a physical connection. When the terms “comprising” or “including” are used, they mean “including but not limited to,” and explicitly indicate an open relationship between the combination, group, series, and the like. In addition, the terms "first," "second," and "third" used in the description and the accompanying drawings of this disclosure are intended to differentiate between different objects, not to describe a specific order.

[0031] A hyperspectral imaging (HSI) system may be a system used to generate hyperspectral images. Compared to black-and-white images, grayscale images, or red-green-blue (RGB) images that lose many wavelength details, hyperspectral images may present spectral information of reflected or transmitted light from various parts of a target object, including light intensity corresponding to multiple wavelengths.

[0032] In some implementations, hyperspectral images may be used for material analysis. For example, plants exhibit different reflection spectra under different conditions, and thus thehyperspectral images may be used in agriculture to analyze plant health, soil conditions, and plant growth, etc. Additionally, in the medical field, hyperspectral images may be used to analyze a patient's skin condition; in the field of autonomous driving, hyperspectral images may be used to analyze whether an object ahead is an animal, metal, or plastic; in environmental monitoring, hyperspectral images may detect whether the ground is polluted or if food contains additives.

[0033] FIG. 1 is a diagram illustrating a hyperspectral imaging system in accordance with an example implementation of the present disclosure.

[0034] Referring to FIG. 1, the hyperspectral imaging system 1 may include a mask 11, an optical dispersion device 10, and a first image sensor 12. The hyperspectral imaging system 1 may capture an input image of a target object, and the input image may be converted into a masked image by the mask 11. The optical dispersion device 10 may then disperses the masked image and forms an image on the first image sensor 12. Accordingly, multiple wavelengths of each pixel of the masked image may be spatially separated by the optical dispersion device 10 and imaged onto the first image sensor 12.

[0035] In some implementations, the hyperspectral imaging system 1 may include, for example, a coded aperture snapshot spectral imager (CASSI).

[0036] In some implementations, as shown in FIG. 1 , the hyperspectral imaging system 1 may further include a lens 13, a beam splitter 14, a second image sensor 15, and a processor 16, where the processor 16 may be coupled to the first image sensor 12 and the second image sensor 15.

[0037] Various components included in the hyperspectral imaging system 1 are described in the following.

[0038] In some implementations, the mask 11 may include a preset or editable pattern, which allows the mask 11 to convert the input image into the masked image.

[0039] It should be noted that the specific pattern of the mask 11 is not limited by the implementations of the present disclosure, and those skilled in the art are allowed to design the pattern of the mask 11 based on their needs.

[0040] In some implementations, the optical dispersion device 10 may be configured to relay an image (e.g., the masked image) to the first image sensor 12. During the process of relaying the image to the first image sensor 12, the optical dispersion device 10 may generate dispersion to spatially separate multiple wavelengths of each pixel of the image, so that the first image sensor 12 may receive a hyperspectral image corresponding to the relayed image (e.g., the masked image). The more spatially separated the multiple wavelengths are, the higher the dispersion capability of the optical dispersiondevice 10, and thus, the higher the resolution of the hyperspectral image.

[0041] In some implementations, additional prisms or prism pairs may be provided (e.g., to the optical dispersion device 10) to increase the dispersion capability of the optical dispersion device 10, thereby improving the resolution of the hyperspectral image.

[0042] In some implementations, additional optical diffraction elements may be provided (e.g., to the optical dispersion device 10) to increase the dispersion capability of the optical dispersion device 10, thereby improving the resolution of the hyperspectral image. The optical diffraction elements may include, but are not limited to, gratings.

[0043] In some implementations, the optical dispersion device 10 may include multiple optical elements, and the image may be relayed to the first image sensor 12 through an optical path. The principal axis of one or more of the multiple optical elements may be offset from an optical axis (e.g., the central axis) of the optical path to increase the dispersion capability of the optical dispersion device 10, thereby improving the resolution of the hyperspectral image.

[0044] Specifically, the optical dispersion device 10 may include at least one first optical element and multiple second optical elements, where the first principal axis of the first optical element may be positioned relative to the optical axis of the optical path with an offset, and the second principal axes of the second optical elements may be all aligned with the optical axis of the optical path. In some examples, all second optical elements may share the same second principal axis, and the first principal axis of the first optical element may be positioned relative to the second principal axis of the second optical elements with the offset.

[0045] In some implementations, the offset may include a parallel displacement. In some implementations, the offset may include an angular deviation. In some implementations, the offset may include both a parallel displacement and an angular deviation.

[0046] The first optical element may include at least one of a lens, a prism, a grating, and a planar mirror, but which is not limited in the present disclosure. The second optical elements may include at least one of a lens, a prism, a grating, and a planar mirror, but which are not limited in the present disclosure.

[0047] In some implementations, the number of at least one first optical element is one.

[0048] In some implementations, the number of at least one first optical element is multiple.

[0049] FIG. 2 is a diagram illustrating an optical dispersion device in accordance with an example implementation of the present disclosure.

[0050] Referring to FIG. 2, in some implementations, the optical dispersion device 10 mayinclude a first lens 101, a second lens 102, a first prism pair 103, a second prism pair 104, a third lens 105, and a fourth lens 106, where the principal axis PAI of the third lens 105 has an offset 01 relative to the optical axis OA, and the first lens 101, the second lens 102, the first prism pair 103, the second prism pair 104, and the fourth lens 106 share the principal axis PA2 aligned with the optical axis OA. In this example, the offset 01 is a parallel displacement (e.g., along the Y-axis) between the optical axis OA and the principal axis PAI, as well as a parallel displacement between the principal axis PA2 and the principal axis PAI.

[0051] In some implementations, the lenses mentioned above may include lens assemblies or cemented lenses, which are not limited in the present disclosure.

[0052] In some implementations, there may be optical element(s) other than the third lens 105 (e.g., at least one of the first lens 101, the second lens 102, the first prism pair 103, the second prism pair 104, and the fourth lens 106) whose principal axis is offset from the optical axis OA. In other words, besides the third lens 105, other optical element(s) may be classified as the first optical element.

[0053] FIG. 3 is a diagram illustrating an optical dispersion device in accordance with an example implementation of the present disclosure.

[0054] Referring to FIG. 3, in some implementations, the optical dispersion device 10 may include a first lens 101, a second lens 102, a first prism pair 103, a second prism pair 104, a third lens 105, and a fourth lens 106, where the principal axis PA3 of the second prism pair 104 has an offset 02 relative to the optical axis OA, and the first lens 101, the second lens 102, the first prism pair 103, the third lens 105, and the fourth lens 106 share the principal axis PA2 aligned with the optical axis OA. In this example, the offset 02 may be an angular deviation between the optical axis OA and the principal axis PA3, as well as an angular deviation between the principal axis PA2 and the principal axis PA3.

[0055] In some implementations, the lenses mentioned above may include lens assemblies or cemented lenses, but which are not limited in the present disclosure.

[0056] It should be noted that, the angular deviation of the principal axis PA3 relative to the principal axis PA2 may include an angle rotated along an axis (e.g., the Z-axis) perpendicular to the principal axis PA2 (e.g., which is parallel to the X-axis). In some implementations, the angular deviation of the principal axis PA3 relative to the principal axis PA2 may also include an angle rotated along the principal axis PA2.

[0057] In some implementations, there may be optical element(s) other than the second prism pair 104 (e.g., at least one of the first lens 101, the second lens 102, the first prism pair 103, the thirdlens 105, and the fourth lens 106) whose principal axis is offset from the optical axis OA. In other words, besides the third lens 105, other optical elements may be classified as the first optical element.

[0058] In some implementations, the optical dispersion device 10 may include, for example, a zoom lens. For example, the fourth lens 106 may include a zoom lens used to adjust the magnification of the optical dispersion device 10.

[0059] It should be noted that, in the implementation shown in FIG. 3, the offset 01 is a parallel displacement of the principal axis PAI relative to the optical axis OA along the Y-axis. In other implementations, the offset may also include parallel displacements along other axes relative to the optical axis OA. Additionally, the offset may include both parallel displacements and angular deviations.

[0060] In some implementations, the optical dispersion device 10 may further include an adjustment element (not shown). The adjustment element may be configured to adjust the offset mentioned above to control the dispersion capability and / or dispersion direction of the optical dispersion device 10. For example, the adjustment element may include mechanical components such as motors, slides, screws, and nuts, but the specific form of the adjustment element is not limited by the present disclosure.

[0061] By adjusting the offset of the principal axis of the first optical element in the optical dispersion device 10 through the adjustment element, the dispersion capability / direction of the optical dispersion device 10 may be controlled.

[0062] Advantageously, the optical dispersion device 10 with the adjustment element may more precisely control the size or capability of the dispersion, which helps improve stability in the manufacturing of the optical dispersion device 10. The reason is that typically, during lens manufacturing, the dispersion generated by each lens may vary significantly. By setting an adjustment element in the optical dispersion device 10, the dispersion of the optical dispersion device 10 may be made more controllable (e.g., to maintain consistency) in a simple and low-cost manner.

[0063] FIG. 4A and FIG. 4B are diagrams illustrating two different dispersion directions in accordance with an example implementation of the present disclosure.

[0064] When the offset is a parallel displacement of the first principal axis of the first optical element relative to the optical axis (or the second principal axis of the second optical element) along the Y-axis, the optical dispersion device 10 may produce linear dispersion in the direction along the Y-axis, as shown in FIG. 4A.

[0065] When the offset includes a parallel displacement of one first principal axis of one firstoptical element relative to the optical axis (or the second principal axis of the second optical element) along the Y-axis, and also includes a parallel displacement of another first principal axis of another first optical element relative to the optical axis (or the second principal axis of the second optical element) along the Z-axis, the optical dispersion device 10 may produce curved dispersion with a direction change in the Y-Z plane, as shown in FIG. 4B.

[0066] Besides the dispersion direction, by adjusting the offset of the principal axis of the first optical element in the optical dispersion device 10 through the adjustment element, the dispersion capability of the optical dispersion device 10 may also be adjusted to increase or decrease the spectral dispersion of the image.

[0067] In some implementations, the adjustment element may be configured to increase the parallel displacement of the first principal axis of the first optical element relative to the optical axis (or the second principal axis of the second optical element) in a specific direction to increase the spectral dispersion in that specific direction, and / or to decrease the parallel displacement of the first principal axis of the first optical element relative to the optical axis (or the second principal axis of the second optical element) in a specific direction to decrease the spectral dispersion in that specific direction.

[0068] In some implementations, the adjustment element may also be configured to increase the angular deviation of the first principal axis of the first optical element relative to the optical axis (or the second principal axis of the second optical element) to increase spectral dispersion, and / or to decrease the angular deviation of the first principal axis of the first optical element relative to the optical axis (or the second principal axis of the second optical element) to decrease spectral dispersion.

[0069] Referring to FIG. 1, in some implementations, the lens 13 may include, for example, an objective lens configured to capture an input image of a target object.

[0070] In some implementations, the beam splitter 14 may be configured to split the input image from the lens 13 to the mask 11 and the second image sensor 15.

[0071] In some implementations, the first image sensor 12 may be configured to convert the image of optical signal into an electronic signal. For example, the first image sensor 12 may include at least one of a charge-coupled device (CCD) and a complementary metal-oxide-semiconductor (CMOS), but the type of the first image sensor 12 is not limited by the present disclosure.

[0072] In some implementations, the second image sensor 15 may be configured to convert the image of optical signal into an electronic signal. For example, the second image sensor 15 may include at least one of a CCD and a CMOS, but the type of the second image sensor 15 is not limited by thepresent disclosure.

[0073] In some implementations, the processor 16 may be configured to receive the digital image (also referred to as the first output image) from the first image sensor 12 and perform an analysis based on the first output image, the configuration of the optical dispersion device 10 (including the parameters of each optical element, the offset mentioned above, etc.), and the pattern of the mask 11. The analysis results may be used in various fields mentioned earlier, such as agriculture, medicine, autonomous driving, and environmental monitoring.

[0074] In some implementations, the processor 16 may be further configured to receive the digital image (also referred to as the second output image) from the second image sensor 15 and perform an analysis based on the first output image, the second output image, the configuration of the optical dispersion device 10 (including the parameters of each optical element, the offset mentioned above, etc.), and the pattern of the mask 11. The analysis results may be used in various fields mentioned earlier, such as agriculture, medicine, autonomous driving, and environmental monitoring. For example, the processor 16 may analyze the spectral information corresponding to each pixel in the second output image based on the first output image, the configuration of the optical dispersion device 10, and the pattern of the mask 11.

[0075] For example, the processor 16 may include a central processing unit (CPU) or other programmable general-purpose or special-purpose microprocessors, digital signal processors (DSPs), programmable controllers, application-specific integrated circuits (ASICs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), or similar components, as well as combinations of these components.

[0076] FIG. 5A and FIG. 5B are diagrams illustrating an image analysis in accordance with an example implementation of the present disclosure.

[0077] In some implementations, the target objects may include, for example, M&M candies and Skittles candies. In RGB images, it is not easy to distinguish M&M candies from Skittles candies of the same color (e.g., yellow). However, since the spectra of the same color M&M candies and Skittles candies are different, the hyperspectral imaging system 1 can analyze and distinguish the same color M&M candies and Skittles candies based on the first output image, the second output image, the configuration of the optical dispersion device 10, and the pattern of the mask 11 using the processor 16.

[0078] FIG. 5A, for example, shows the spectral information of yellow M&M candies (shown in blue) and yellow Skittles candies (shown in red). For example, the spectral information of yellowM&M candies and yellow Skittles candies may be pre-obtained known information.

[0079] FIG. 5B, for example, shows a superimposed image of the first output image and the second output image. Specifically, the second output image has not pass through the optical dispersion device 10; therefore, the second output image may be, for example, a clear RGB image of the target object. Since the first output image has passed through the optical dispersion device 10, multiple wavelengths of reflected light from the target object (e.g., multiple point light sources) may be spatially dispersed in the first output image. Therefore, the superimposed image of the first output image and the second output image may be, for example, a blurred image as shown in FIG. 5B.

[0080] FIG. 5C, for example, marks the yellow M&M candies and yellow Skittles candies in the superimposed image. For example, the processor 16 may distinguish the yellow M&M candies (shown in blue) and yellow Skittles candies (shown in red) in the superimposed image (or the second output image) based on the first output image, the second output image, the configuration of the optical dispersion device 10, and the pattern of the mask 11, using the known information from FIG. 5 A.

[0081] It should be noted that, FIGS. 5A to 5C exemplarily illustrate the analysis that the processor 16 may perform based on the first output image, the second output image, the configuration of the optical dispersion device 10, and the pattern of the mask 11. However, the specific analysis items or contents are not limited in the implementations of the present disclosure. In some implementations, a user may, for example, click on the image of FIG. 5B, and the processor 16 may determine the objects with the same (substantially the same or similar) spectrum as the clicked point and mark them with the same color. For example, if the user first clicks on a yellow M&M candy in the image of FIG. 5B, the processor 16 may, for example, mark all areas with the same spectrum in blue as shown in FIG. 5C. Thus, the user may know which areas in the image correspond to the yellow M&M candies. For example, if the user then clicks on a yellow Skittles candy in the image of FIG. 5B, the processor 16 may, for example, mark all areas with the same spectrum in red as shown in FIG. 5C. Thus, the user may know which areas in the image correspond to the yellow Skittles candies.

[0082] FIG. 6 is a flowchart for generating a hyperspectral image in accordance with an example implementation of the present disclosure.

[0083] Referring to FIG. 6, process 600 may be used to generate a hyperspectral image corresponding to a target object.

[0084] In operation 610, a mask may be provided.

[0085] In some implementations, the mask 11 of the hyperspectral imaging system 1 may be provided.

[0086] In operation 620, an optical dispersion device may be provided.

[0087] In some implementations, the optical dispersion device 10 of the hyperspectral imaging system 1 may be provided.

[0088] In operation 630, an input image may be converted into a masked image through the mask.

[0089] In some implementations, the input image may be, for example, an image captured of the target object. It should be noted that the input image is an optical image, where each pixel may be considered a point light source, thus including light signals of multiple wavelengths. In other words, the input image is not a digital image converted by an image sensor.

[0090] In some implementations, the pattern of the mask may at least partially block the input image, so that the input image passing through the mask may form a masked image.

[0091] In operation 640, the masked image may be relayed to an image sensor through the optical dispersion device.

[0092] In some implementations, during the process of relaying the masked image to the image sensor, the optical dispersion device may spatially separate the light of different wavelengths in the masked image. Therefore, the image sensor may generate a corresponding digital image, which is the hyperspectral image, including spectral information of multiple parts of the target object.

[0093] In summary, implementations of the present disclosure provide a hyperspectral imaging system for generating hyperspectral images, where the dispersion capability of an optical dispersion device in the hyperspectral imaging system can be changed through the principal axis offset of at least one optical element in the optical dispersion device. Accordingly, dispersion can be effectively increased to improve spectral resolution while maintaining costs. Additionally, the implementations of the present disclosure also provide a technique using an adjustment element to adjust the offset, which can adjust the dispersion size, direction, and / or trajectory to optimize subsequent calculations in response to the content being captured or the target object.

[0094] Based on the above description, it is apparent that various techniques can be configured to implement the concepts described in this application without departing from their scope. Furthermore, although certain implementations have been specifically described and illustrated, those skilled in the art will recognize that variations and modifications can be made in form and detail without departing from the scope of the concepts. Thus, the described implementations are to be considered in all respects as illustrative and not restrictive. Moreover, it should be understood that this application is not limited to the specific implementations described above, but many rearrangements, modifications, and substitutions can be made within the scope of the present disclosure.

Claims

WHAT IS CLAIMED IS:

1. An optical dispersion device for relaying an image to an image sensor, comprising: a first optical element having a first principal axis; and a plurality of second optical elements sharing a second principal axis, wherein the first principal axis is positioned relative to the second principal axis with an offset, and the offset comprises at least one of a parallel displacement and an angular deviation.

2. The optical dispersion device of claim 1, wherein the image is relayed to the image sensor through an optical path, the second principal axis aligns with an optical axis of the optical path, and the offset exists between the first principal axis and the optical axis.

3. The optical dispersion device of claim 1 or 2, wherein the angular deviation comprises an angle rotated along the second principal axis.

4. The optical dispersion device of any preceding claim, wherein the angular deviation comprises an angle rotated along a first axis, and the first axis is perpendicular to the second principal axis.

5. The optical dispersion device of any preceding claim, further comprising: an adjustment element configured to adjust the offset.

6. The optical dispersion device of claim 5, wherein the adjustment element is further configured to: increase the parallel displacement to increase spectral dispersion of the image; and decrease the parallel displacement to reduce the spectral dispersion of the image.

7. The optical dispersion device of claim 5 or 6, wherein the adjustment element is further configured to: increase the angular deviation to increase spectral dispersion of the image; and decrease the angular deviation to reduce the spectral dispersion of the image.

8. The optical dispersion device of any preceding claim, wherein the first optical element and the plurality of second optical elements comprise a zoom lens, and the zoom lens is configured to adjust a magnification of the optical dispersion device.

9. The optical dispersion device of any preceding claim, wherein the first optical element comprises at least one of a lens, a prism, a grating, and a planar mirror.

10. The optical dispersion device of any preceding claim, wherein the plurality of second optical elements comprises at least one of a lens, a prism, a grating, and a planar mirror.

11. A hyperspectral imaging system, comprising: a mask; a first image sensor; and the optical dispersion device according to any one of claims 1 to 10, wherein the optical dispersion device is configured to relay a mask image from the mask to the first image sensor.

12. The hyperspectral imaging system of claim 11, further comprising: a processor coupled to the first image sensor and configured to perform an analysis based on a first output image from the first image sensor, a configuration of the optical dispersion device, and a pattern of the mask.

13. The hyperspectral imaging system of claim 12, further comprising: an objective lens; a second image sensor coupled to the processor; and a beam splitter configured to split an input image from the objective lens to the mask and the second image sensor, wherein the processor is further configured to perform the analysis based on the first output image from the first image sensor, a second output image from the second image sensor, the configuration of the optical dispersion device, and the pattern of the mask.

14. The hyperspectral imaging system of claim 12 or 13, wherein the configuration of the optical dispersion device comprises the offset.

15. A method for generating a hyperspectral image, comprising: providing a mask; providing the optical dispersion device according to any of claims 1 to 10; converting an input image into a mask image through the mask; and relaying the mask image to an image sensor through the optical dispersion device.

16. An optical dispersion device for relaying an image to an image sensor, comprising: a first optical element having a first principal axis; a plurality of second optical elements sharing a second principal axis; and an adjustment element configured to adjust an offset between the first principal axis and the second principal axis, wherein the offset comprises at least one of a parallel displacement and an angular deviation.

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