A three-dimensional stereoscopic hyperspectral imaging system and imaging method

Abstract

The present invention provides a three-dimensional stereoscopic hyperspectral imaging system and an imaging method to solve the technical problem that the adjustment and determination process of various parameters in the existing three-dimensional stereoscopic imaging during stereoscopic shooting is very cumbersome and complex. Even if micron-level calibration has been carried out at the factory, manual adjustment still needs to be performed during actual shooting to ensure good consistency and matching of the images of the two cameras. The present invention includes two optical paths of radiation or reflection from the measured target. After the outgoing light is compressed and collimated by the front collimation system and passes through the front polarizer, linearly polarized light is formed, and then enters the acousto-optic tunable filter to generate acousto-optic interaction with ultrasonic waves, producing 0th-order transmitted light and ±1st-order diffracted light. The diffracted light passes through the rear analyzer and the imaging mirror and is focused on the imaging detector, and the image with target information is collected and transmitted to the computer control terminal. Finally, by synthesizing the two narrow-band light images, a three-dimensional stereoscopic hyperspectral image of the target is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of three-dimensional hyperspectral imaging, and particularly relates to a three-dimensional hyperspectral imaging system and an imaging method. Background Art

[0002] For humans, "a picture is worth a thousand words", and the information feedback efficiency from images far exceeds other media such as language. As the most important perception means of humans, the absorption rate of the visual system for the signal volume is 70%-80% of the total signal volume. The process of relying on vision to understand the objective world and obtain useful information is irreplaceable. Through the reception of optical signals, the visual system can feel, acquire, and understand and analyze the appearance of external things. The visual perception ability has the most complex system. In the real world, the objectively existing things and scenes are all three-dimensional. The natural environment can be obtained as different two-dimensional visual images through our binoculars. After continuous processing by the visual perception system, the spatial information of any object can be completely obtained, thus forming a stereoscopic visual scene. When vision is fully and organically integrated with the natural environment, we can easily understand the whole world.

[0003] Two-dimensional vision is a planar image, which is used to identify objects by analysis or comparison. It can see the features on a plane of an object and can be used for defect detection, icon alignment, bar code and character recognition, and various two-dimensional image geometric analyses. Although two-dimensional vision technology is mature, with the increasing actual requirements and the more and more complex and harsh measured environmental conditions, the defects of the planar vision system have become increasingly prominent. Because it cannot obtain the spatial coordinate information of an object, it does not support the acquisition of information related to shape, such as: the smoothness, depth, height of an object, or the positional relationship of an object with a contact side. The three-dimensional technology has continuously made breakthroughs and is incomparable with two-dimensional in terms of accuracy, practicality, etc. Three-dimensional machine vision is constantly replacing two-dimensional systems and becoming the latest trend in the current vision development. The real world seen by the human eye is not just a simple planar image, but a three-dimensional structure with depth of field. When observing the same object, since many light rays reflected by the measured target have a certain angle and there is a certain distance between the two eyes, the images seen are also different. The brain combines these two pictures to form a kind of depth three-dimensional vision. This kind of vision with a sense of three-dimensionality is three-dimensional imaging. The three-dimensional stereoscopic imaging technology can quickly and timely obtain a large amount of accurate and objective information of the measured target. It is a comprehensive detection technology that reveals the characteristic properties and changes of an object through analysis, and can form comprehensive information in multiple levels, multiple ways, multiple sides, and all-round, greatly broadening the research breadth and depth. The three-dimensional hyperspectral imaging technology is the most advanced stereoscopic display technology in the world at present. It is a comprehensive detection technology that can accurately reveal the characteristics and changes of an object, greatly broadening the research breadth and depth of target recognition.

[0004] Hyperspectral imaging technology is a target detection method with more narrowband spectra developed on the basis of airborne or spaceborne spectral imaging technology. Its basic principle of action is to collect the reflection or radiation data of the target to be measured in a large number of adjacent or overlapping dense spectral bands. It can not only provide rich spatial structure information and numerous spectral information of the target to be identified, but also provide the surface two-dimensional data of the target to be identified and the third-dimensional spectral data of the pixels corresponding to any area in the measured space. The absorption peak half-width of many surface substances is between 20 and 40 nm. Since the spectral detection resolution of hyperspectral imaging technology is generally less than 10 nm, this technology can detect more surface substances with spectral characteristics. That is to say, hyperspectral technology can identify those substances that are powerless for multispectral technology, depict the target to be identified with a complete and continuous spectral curve to form spectral data, and can indirectly reflect the component information of the target to be identified.

[0005] Stereoscopic photography mainly simulates the imaging process of the human eye. When shooting, two cameras are used to capture two-dimensional images of the left and right perspectives respectively. When playing, certain technical means are adopted so that the viewer can only see the picture of the left camera with the left eye and the picture of the right camera with the right eye. After the two pictures are fused by the brain, a three-dimensional sense of depth is generated. The actual stereoscopic shooting is not as simple as described. Due to the sensitivity of the human eye to the perception of three-dimensional images, even a slight change in any parameter such as focal length, camera spacing, and angle may affect the three-dimensional effect of the picture. Therefore, the adjustment and determination of each parameter in stereoscopic shooting is a very cumbersome and complex process. To ensure the naturalness of the stereoscopic picture and reduce visual fatigue during viewing, it is necessary to ensure that the two cameras maintain a high degree of matching, consistency, and synchronization during stereoscopic shooting. However, it is not easy to always maintain the matching of the pictures within the focal length change range from telephoto to wide-angle for the two lenses. Although general equipment manufacturers will calibrate their cameras to the micron level before leaving the factory, during actual shooting, in order to avoid possible imaging deviations, users still need to make manual adjustments to ensure that the pictures of the two cameras maintain good consistency and matching. Summary of the Invention

[0006] The object of the present invention is to solve the technical problem that the adjustment and determination process of each parameter in the existing three-dimensional stereoscopic imaging during stereoscopic shooting is very cumbersome and complex. Even though it has been calibrated to the micron level before leaving the factory, during actual shooting, manual adjustments still need to be made to ensure that the pictures of the two cameras maintain good consistency and matching, and to provide a three-dimensional stereoscopic hyperspectral imaging system and imaging method.

[0007] The inventive concept of the present invention is as follows: Select two optical paths from the radiation or reflection of the target to be measured. After the outgoing light passes through the pre-collimation system for compression and collimation, linearly polarized light is formed after polarization by the pre-polarizer, and then enters the acousto-optic tunable filter to undergo acousto-optic interaction with ultrasonic waves, generating 0th-order transmitted light and ±1st-order diffracted light. The diffracted light passes through the post-analyzer and is focused on the imaging detector by the imaging lens, and the image with target information is collected and transmitted to the computer control terminal. Finally, by synthesizing the two narrow-band light images, a three-dimensional stereoscopic hyperspectral image of the target is obtained.

[0008] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] A three-dimensional stereoscopic hyperspectral imaging system, characterized in that it includes two optical paths for receiving the radiation or reflection from the target to be measured, an acousto-optic tunable filter, an acousto-optic tunable filter radio frequency driver, an image acquisition card, and a computer control terminal;

[0010] The outgoing light of the radiation or reflection received by each optical path sequentially passes through the pre-collimation system for compression and collimation and is polarized by the pre-polarizer to form linearly polarized light. The linearly polarized light enters the acousto-optic tunable filter to undergo acousto-optic interaction with the ultrasonic waves emitted by the acousto-optic tunable filter radio frequency driver, respectively generating 0th-order transmitted light and +1st-order diffracted light and 0th-order transmitted light and -1st-order diffracted light. The ±1st-order diffracted lights respectively pass through the post-analyzer and are focused on the imaging detector by the imaging lens;

[0011] The polarization directions of the pre-polarizers on the two optical paths are perpendicular, the polarization directions of the post-analyzers are also perpendicular, and the polarization directions of the pre-polarizers and post-analyzers on each optical path are perpendicular;

[0012] The image acquisition card is connected to the imaging detectors on each optical path. The image acquisition card is used to collect the images with target information and transmit them to the computer control terminal for storage;

[0013] The computer control terminal is used to synthesize the two narrow-band light images, obtain the three-dimensional stereoscopic hyperspectral image of the target, and control the frequency value of the ultrasonic waves generated by the acousto-optic tunable filter radio frequency driver.

[0014] Further, the two optical paths are the first optical path and the second optical path;

[0015] The first optical path includes a first pre - collimation system, a first pre - polarizer, an acousto - optic tunable filter, a first post - analyzer, a first imaging mirror, and a first imaging detector, which are arranged in sequence along the optical path. The first light beam forms parallel light after being compressed and collimated by the first pre - collimation system. The parallel light is incident on the first pre - polarizer to form a first linearly polarized light. The first linearly polarized light enters the acousto - optic tunable filter and undergoes acousto - optic interaction with the ultrasonic wave emitted by the radio - frequency drive of the acousto - optic tunable filter, generating a 0 - order transmitted light and a +1 - order diffracted light. The +1 - order diffracted light is transmitted through the first post - analyzer and then focused on the first imaging detector by the first imaging mirror;

[0016] The second optical path includes a second pre - collimation system, a second pre - polarizer, an acousto - optic tunable filter, a second post - analyzer, a second imaging mirror, and a second imaging detector, which are arranged in sequence along the optical path. The second light beam forms parallel light after being compressed and collimated by the second pre - collimation system. The parallel light is incident on the second pre - polarizer to form a second linearly polarized light. The second linearly polarized light enters the acousto - optic tunable filter and undergoes acousto - optic interaction with the ultrasonic wave emitted by the radio - frequency drive of the acousto - optic tunable filter, generating a 0 - order transmitted light and a -1 - order diffracted light. The -1 - order diffracted light is transmitted through the second post - analyzer and then focused on the second imaging detector by the second imaging mirror;

[0017] The polarization directions of the first pre - polarizer and the second pre - polarizer are perpendicular; the polarization directions of the first pre - polarizer and the first post - analyzer are perpendicular; the polarization directions of the second pre - polarizer and the second post - analyzer are perpendicular.

[0018] Further, a first reflecting mirror, a second reflecting mirror, and a right - angle reflecting prism are respectively arranged between the first pre - polarizer and the second pre - polarizer and the acousto - optic tunable filter. The first linearly polarized light and the second linearly polarized light are respectively refracted by the first reflecting mirror and the second reflecting mirror and then incident on two right - angle sides of the right - angle reflecting prism, and after reflection, they are incident on the acousto - optic tunable filter.

[0019] Further, the first pre - collimation system and the second pre - collimation system are symmetrically arranged with respect to the measured target, and the angles between them and the measured target are the same.

[0020] Further, the first post - analyzer is used to completely filter out the 0 - order transmitted light in the first linearly polarized light, and the +1 - order diffracted light completely passes through;

[0021] The second post - analyzer is used to completely filter out the 0 - order transmitted light in the second linearly polarized light, and the -1 - order diffracted light completely passes through.

[0022] Further, the first pre - polarizer, the second pre - polarizer, the first post - analyzer, and the second post - analyzer are polarizing sheets or polarizing prisms.

[0023] Further, the right-angle reflecting prism is an isosceles right-angle reflecting prism, and high-reflection films are coated on two right-angle sides.

[0024] The present invention also provides a three-dimensional stereoscopic hyperspectral imaging method. Based on the above three-dimensional stereoscopic hyperspectral imaging system, it is characterized in that it includes the following steps:

[0025] Step 1), use the pre-collimation systems on two optical paths to respectively collect the radiation light or reflected light of the target to be measured. After being compressed and collimated by the pre-collimation systems, it is incident on the pre-polarizer to form two parallel polarized lights with perpendicular polarization directions;

[0026] Step 2), control the radio frequency drive of the acousto-optic tunable filter through the computer control terminal, so that the ultrasonic waves emitted by it satisfy the momentum matching condition with the two polarized lights in the acousto-optic tunable filter, an acousto-optic interaction occurs, reaching an equal-value balance, and generating +1-order diffracted light, -1-order diffracted light and 0-order transmitted light;

[0027] Step 3), tune the post-analyzer so that the 0-order transmitted light in the two polarized lights is completely filtered out, and the +1-order diffracted light and -1-order diffracted light are completely transmitted and imaged on the imaging detector;

[0028] Step 4), use the image acquisition card to respectively collect the spectral information of the +1-order diffracted light and -1-order diffracted light and transmit it to the computer control terminal;

[0029] Step 5), use the computer control terminal to synthesize the +1-order diffracted light and -1-order diffracted light images with the spectral information of the target to be measured to obtain the three-dimensional stereoscopic hyperspectral image of the target to be measured.

[0030] Further, when the pre-collimation systems on two optical paths collect the radiation light or reflected light of the target to be measured (1), the pre-collimation systems are symmetrically arranged relative to the target to be measured (1), and the included angles between them and the target to be measured (1) are the same.

[0031] Further, it further includes Step 6): use the three-dimensional stereoscopic hyperspectral image of the target to be measured (1) obtained in Step 5) to judge whether the included angles between the pre-collimation systems on two optical paths and the target to be measured (1) are the same;

[0032] If they are not the same, correct the obtained three-dimensional stereoscopic hyperspectral image of the target to be measured (1), and use the corrected three-dimensional stereoscopic hyperspectral image as the final three-dimensional stereoscopic hyperspectral image of the target to be measured (1);

[0033] If they are the same, directly use the three-dimensional stereoscopic hyperspectral image of the target to be measured (1) as the final three-dimensional stereoscopic hyperspectral image of the target to be measured (1).

[0034] Further, in step 2), the momentum matching and equivalent balance mean that the ultrasonic wave simultaneously undergoes acousto-optic interaction with the +1st order diffracted light and the -1st order diffracted light, and the intensities of the two diffracted lights are the same.

[0035] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0036] 1. The three-dimensional stereoscopic hyperspectral imaging system provided by the present invention combines three-dimensional stereoscopic imaging with hyperspectral technology. Existing three-dimensional stereoscopic imaging systems collect targets in the full wavelength band, that is, the two-dimensional target information output by a simple camera, without spectral dimension information. An acousto-optic tunable filter is added in front of the detector of this system. The acousto-optic tunable filter is used to split the incident light from the target, filter the incident light into any desired narrowband monochromatic light, and thus add spectral dimension information to the two-dimensional image information of the target.

[0037] 2. The three-dimensional stereoscopic hyperspectral imaging system provided by the present invention is a new type of high-throughput system. It uses an acousto-optic tunable filter for spectral filtering, combines stereoscopic vision, and simultaneously obtains hyperspectral and three-dimensional information of the target, and is expected to provide a new idea for experimental research in fields such as aerospace navigation, geological exploration, drug supervision, construction engineering, microscopic optics, cultural heritage protection, and food production.

[0038] 3. The three-dimensional stereoscopic hyperspectral imaging method provided by the present invention uses this system to detect the target. The detection result not only includes traditional three-dimensional stereoscopic information, but also adds spectral information, and moreover, it is hyperspectral information. The final acquisition result will be the three-dimensional stereoscopic information of the target under any narrowband single wavelength within the tuning range, which will filter out many interference factors and make the detection result of the target more accurate. The system adds an acousto-optic tunable filter that can flexibly modulate the output of narrowband wavelengths. The computer control terminal can simultaneously control the acousto-optic tunable filter and the imaging detector, and can accurately record the three-dimensional stereoscopic hyperspectral image of any narrowband monochromatic target. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic structural diagram of an embodiment of the three-dimensional stereoscopic hyperspectral imaging system of the present invention;

[0040] Reference Signs:

[0041] 1 - Measured target, 2 - First pre - collimation system, 3 - Second pre - collimation system, 4 - First pre - polarizer, 5 - Second pre - polarizer, 6 - Right - angle reflecting prism, 7 - First mirror, 8 - Second mirror, 9 - Acousto - optic tunable filter, 10 - Radio - frequency driver for acousto - optic tunable filter, 11 - First post - analyzer, 12 - Second post - analyzer, 13 - First imaging lens, 14 - Second imaging lens, 15 - First imaging detector, 16 - Second imaging detector, 17 - Image acquisition card, 18 - Computer control terminal. Detailed implementation mode

[0042] To make the objectives, advantages and features of the present invention clearer, the following further details a three - dimensional stereoscopic hyperspectral imaging system and imaging method proposed by the present invention in combination with the accompanying drawings and specific embodiments. Those skilled in the art should understand that these implementation modes are only used to explain the technical principles of the present invention, and the purpose is not to limit the protection scope of the present invention. In the description of the present invention, it should be noted that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0043] As Figure 1 shown, a three - dimensional stereoscopic hyperspectral imaging system proposed by the present invention includes a first optical path and a second optical path for the radiation light or reflected light from the measured target 1, an image acquisition card 17 for collecting and storing target information, and a computer control terminal 18; the first optical path and the second optical path are symmetrically arranged with respect to the measured target 1, and the angles between the measured target 1 and the first optical path and the second optical path are the same. If the angles between the measured target 1 and the first optical path and the second optical path are different, the detected images need to be corrected after the detection.

[0044] The first optical path includes a first pre - collimation system 2, a first pre - polarizer 4, a first mirror 7, a right - angle reflecting prism 6, an acousto - optic tunable filter 9, a first post - analyzer 11, a first imaging lens 13, and a first imaging detector 15 arranged in sequence along the optical path.

[0045] The incident light of the first path from the measured target 1 is compressed and collimated by the first pre - collimation system 2 to form parallel light, the parallel light is incident on the first pre - polarizer 4 to form first - line polarized light, and the first - line polarized light passes through the first mirror 7 and the right - angle reflecting prism 6 in sequence and then vertically enters the acousto - optic tunable filter 9 to undergo acousto - optic interaction with the ultrasonic wave emitted by the radio - frequency driver 10 of the acousto - optic tunable filter, generating 0 - order transmitted light and +1 - order diffracted light. By tuning the first post - analyzer 11, exactly the 0 - order transmitted light can be completely filtered out, and the +1 - order diffracted light completely passes through. The +1 - order diffracted light is focused on the first imaging detector 15 by the first imaging lens 13 after passing through the first post - analyzer 11.

[0046] The second optical path includes a second pre - collimation system 3, a second pre - polarizer 5, a second reflector 8, a right - angle reflecting prism 6, an acousto - optic tunable filter 9, a second post - analyzer 12, a second imaging lens 14, and a second imaging detector 16, which are arranged in sequence along the optical path.

[0047] The incident light of the second path from the measured target 1 forms parallel light after being compressed and collimated by the second pre - collimation system 3. The parallel light is incident on the second pre - polarizer 5 to form second linearly polarized light. The polarization direction of the second pre - polarizer 5 is perpendicular to that of the first pre - polarizer 4. The second linearly polarized light passes through the second reflector 8 and the right - angle reflecting prism 6 in sequence and then vertically enters the acousto - optic tunable filter 9, where it undergoes acousto - optic interaction with the ultrasonic wave emitted by the acousto - optic tunable filter radio - frequency driver 10, generating 0 - order transmitted light and - 1 - order diffracted light. By tuning the second post - analyzer 12, the 0 - order transmitted light can be exactly filtered out completely, and the - 1 - order diffracted light passes through completely. The - 1 - order diffracted light is focused on the second imaging detector 16 by the second imaging lens 14 after passing through the second post - analyzer 12.

[0048] The image acquisition card 17 is connected to the first imaging detector 15 and the second imaging detector 16, and is used to acquire images with target information, and then transmit them to the computer control terminal 18 for storage. The computer control terminal 18 obtains the three - dimensional stereoscopic hyperspectral image of the target by synthesizing the two narrow - band light images.

[0049] By tuning the ultrasonic frequency value emitted by the acousto - optic tunable filter radio - frequency driver 10 through the computer control terminal 18, the two parallel light beams can just satisfy the momentum matching condition with the ultrasonic wave at the same time and then undergo acousto - optic interaction.

[0050] The first pre - polarizer 4 and the second pre - polarizer 5 can be polarization instruments such as polarizing films and polarizing prisms that can change natural light into linearly polarized light. The right - angle reflecting prism 6, the first reflector 7, and the second reflector 8 are mainly used to fold back the two - path polarized light into two parallel light beams, reducing the size of the optical system. The right - angle reflecting prism 6 is an isosceles right - angle reflecting prism, and high - reflection films are coated on the two right - angle sides (surfaces).

[0051] After passing through the acousto - optic tunable filter 9, the first linearly polarized light and the second linearly polarized light filter the two parallel polarized light beams and output monochromatic light in a narrow - band manner. The 0 - order transmitted light in the monochromatic light is filtered out by the first post - analyzer 11 and the second post - analyzer 12, and the narrow - band output monochromatic polarized light passes through.

[0052] The three - dimensional stereoscopic hyperspectral imaging method based on the above three - dimensional stereoscopic hyperspectral imaging system includes the following steps:

[0053] Step 1): The first pre-collimation system 2 and the second pre-collimation system 3 respectively collect the radiation light or reflected light of the target to be measured 1. After being compressed and collimated by the first pre-collimation system 2 and the second pre-collimation system 3, the light is incident on the first pre-polarizer 4 and the second pre-polarizer 5, forming two parallel polarized lights with perpendicular polarization directions.

[0054] Step 2): The computer control terminal 18 controls the radio frequency drive 10 of the acousto-optic tunable filter, so that the ultrasonic wave emitted by it satisfies the momentum matching condition with the two polarized lights in the acousto-optic tunable filter 9, and acousto-optic interaction occurs, reaching an equivalent balance, generating +1 order diffracted light, -1 order diffracted light and 0 order transmitted light.

[0055] Momentum matching and equivalent balance mean that the ultrasonic wave simultaneously has acousto-optic interaction with the +1 order diffracted light and the -1 order diffracted light, and the intensities of the two diffracted lights are the same.

[0056] Step 3): Tune the first post-analyzer 11 and the second post-analyzer 12 so that the 0 order transmitted light in the two polarized lights is completely filtered out, and the +1 order diffracted light and the -1 order diffracted light are completely transmitted, and are imaged on the first imaging detector 15 and the second imaging detector 16.

[0057] Step 4): Use the image acquisition card 17 to collect the spectral information of the +1 order diffracted light and the -1 order diffracted light respectively, and transmit it to the computer control terminal 18.

[0058] Step 5): Use the computer control terminal 18 to synthesize the images of the +1 order diffracted light and the -1 order diffracted light with the spectral information of the target to be measured 1, and obtain the three-dimensional stereoscopic hyperspectral image of the target to be measured 1.

[0059] It further includes Step 6): Use the three-dimensional stereoscopic hyperspectral image of the target to be measured (1) obtained in Step 5) to judge whether the angles between the pre-collimation systems on the two optical paths and the target to be measured (1) are the same;

[0060] If they are not the same, correct the obtained three-dimensional stereoscopic hyperspectral image of the target to be measured (1), and use the corrected three-dimensional stereoscopic hyperspectral image as the final three-dimensional stereoscopic hyperspectral image of the target to be measured (1);

[0061] If they are the same, directly use the three-dimensional stereoscopic hyperspectral image of the target to be measured (1) as the final three-dimensional stereoscopic hyperspectral image of the target to be measured (1).

[0062] The present invention uses an acousto-optic tunable filter to filter the incident light and output monochromatic light for spectral filtering, combines stereoscopic vision, and simultaneously obtains hyperspectral and target three-dimensional information, and is expected to provide a new idea for experimental research in fields such as aerospace navigation, geological exploration, drug supervision, construction engineering, microscopic optics, cultural heritage protection, and food production.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A three-dimensional hyperspectral imaging system, characterized in that: it includes two optical paths for receiving radiation or reflection from the measured target (1), an acousto-optic tunable filter (9), an acousto-optic tunable filter radio frequency driver (10), an image acquisition card (17), and a computer control terminal (18); for each of the two optical paths, the outgoing light of the received radiation or reflection passes through a pre-collimation system for compression and collimation and a pre-polarizer for polarization in sequence to form linearly polarized light. The linearly polarized light enters the acousto-optic tunable filter (9) and undergoes acousto-optic interaction with the ultrasonic wave emitted from the acousto-optic tunable filter radio frequency driver (10), generating 0th-order transmitted light and +1st-order diffracted light, and 0th-order transmitted light and -1st-order diffracted light respectively. The ±1st-order diffracted lights pass through a post-analyzer and are focused on an imaging detector by an imaging mirror respectively; the polarization directions of the pre-polarizers on the two optical paths are perpendicular, the polarization directions of the post-analyzers are also perpendicular, and the polarization directions of the pre-polarizer and the post-analyzer on each optical path are perpendicular; the image acquisition card (17) is connected to the imaging detectors on each optical path. The image acquisition card (17) is used to acquire images with target information and transmit them to the computer control terminal (18) for storage; the computer control terminal (18) is used to synthesize the images of two narrowband lights to obtain a three-dimensional hyperspectral image of the target and control the frequency value of the ultrasonic wave generated by the acousto-optic tunable filter radio frequency driver (10).

2. The three-dimensional hyperspectral imaging system according to claim 1, characterized in that: the two optical paths are a first optical path and a second optical path; the first optical path includes a first pre-collimation system (2), a first pre-polarizer (4), a first post-analyzer (11), a first imaging mirror (13), and a first imaging detector (15) arranged in sequence along the optical path. The light of the first path forms parallel light after being compressed and collimated by the first pre-collimation system (2). The parallel light is incident on the first pre-polarizer (4) to form first linearly polarized light. The first linearly polarized light enters the acousto-optic tunable filter (9) and undergoes acousto-optic interaction with the ultrasonic wave emitted from the acousto-optic tunable filter radio frequency driver (10), generating 0th-order transmitted light and +1st-order diffracted light. The +1st-order diffracted light is transmitted through the first post-analyzer (11) and is focused on the first imaging detector (15) by the first imaging mirror (13); the second optical path includes a second pre-collimation system (3), a second pre-polarizer (5), a second post-analyzer (12), a second imaging mirror (14), and a second imaging detector (16) arranged in sequence along the optical path. The light of the second path forms parallel light after being compressed and collimated by the second pre-collimation system (3). The parallel light is incident on the second pre-polarizer (5) to form second linearly polarized light. The second linearly polarized light enters the acousto-optic tunable filter (9) and undergoes acousto-optic interaction with the ultrasonic wave emitted from the acousto-optic tunable filter radio frequency driver (10), generating 0th-order transmitted light and -1st-order diffracted light. The -1st-order diffracted light is transmitted through the second post-analyzer (12) and is focused on the second imaging detector (16) by the second imaging mirror (14); The polarization directions of the first pre - polarizer (4) and the second pre - polarizer (5) are perpendicular; the polarization directions of the first pre - polarizer (4) and the first post - analyzer (11) are perpendicular; the polarization directions of the second pre - polarizer (5) and the second post - analyzer (12) are perpendicular.

3. The three - dimensional stereoscopic hyperspectral imaging system according to claim 2, characterized in that: It further includes a first reflector (7), a second reflector (8) and a right - angle reflecting prism (6) respectively arranged between the first pre - polarizer (4), the second pre - polarizer (5) and the acousto - optic tunable filter (9); the first linearly polarized light and the second linearly polarized light are incident on two right - angled sides of the right - angle reflecting prism (6) after the optical paths are deflected by the first reflector (7) and the second reflector (8) respectively, and are incident on the acousto - optic tunable filter (9) after reflection.

4. The three - dimensional stereoscopic hyperspectral imaging system according to claim 3, characterized in that: The first post - analyzer (11) is used to completely filter out the 0 - order transmitted light in the first linearly polarized light, and the + 1 - order diffracted light is completely transmitted; The second post - analyzer (12) is used to completely filter out the 0 - order transmitted light in the second linearly polarized light, and the - 1 - order diffracted light is completely transmitted.

5. The three - dimensional stereoscopic hyperspectral imaging system according to claim 4, characterized in that: The first pre - polarizer (4), the second pre - polarizer (5), the first post - analyzer (11) and the second post - analyzer (12) are polarizing sheets or polarizing prisms.

6. The three - dimensional stereoscopic hyperspectral imaging system according to claim 5, characterized in that: The right - angle reflecting prism (6) is an isosceles right - angle reflecting prism, and high - reflection films are coated on two right - angled sides.

7. A three - dimensional stereoscopic hyperspectral imaging method, based on the three - dimensional stereoscopic hyperspectral imaging system according to any one of claims 1 - 6, characterized in that, it includes the following steps: Step 1): Use the pre - collimation systems on two optical paths to collect the radiation light or reflected light of the measured target (1) respectively. After being compressed and collimated by the pre - collimation systems, they are incident on the pre - polarizer to form two parallel polarized lights with perpendicular polarization directions; Step 2): Control the radio - frequency drive (10) of the acousto - optic tunable filter through the computer control terminal (18) so that the ultrasonic waves emitted by it satisfy the momentum - matching condition with the two polarized lights in the acousto - optic tunable filter (9), and acousto - optic interaction occurs to reach an equivalent balance, generating + 1 - order diffracted light, - 1 - order diffracted light and 0 - order transmitted light; Step 3): Tune the post - analyzer so that the 0 - order transmitted light in the two polarized lights is completely filtered out, and the + 1 - order diffracted light and the - 1 - order diffracted light are completely transmitted, and are imaged on the imaging detector; Step 4): Use the image acquisition card (17) to collect the spectral information of the + 1 - order diffracted light and the - 1 - order diffracted light respectively, and transmit it to the computer control terminal (18); Step 5): Use the computer control terminal (18) to synthesize the images of the + 1 - order diffracted light and the - 1 - order diffracted light with the spectral information of the measured target (1) to obtain the three - dimensional stereoscopic hyperspectral image of the measured target (1).

8. The three-dimensional hyperspectral imaging method according to claim 7, characterized in that: In step 1), when the pre-collimation systems on two optical paths collect the radiation light or reflected light of the target to be measured (1), the pre-collimation systems are symmetrically arranged with respect to the target to be measured (1), and the angles between them and the target to be measured (1) are the same.

9. The three-dimensional hyperspectral imaging method according to claim 7, characterized in that, it further includes step 6): using the three-dimensional hyperspectral image of the target to be measured (1) obtained in step 5), determining whether the angles between the pre-collimation systems on two optical paths and the target to be measured (1) are the same; if they are not the same, correcting the obtained three-dimensional hyperspectral image of the target to be measured (1), and using the corrected three-dimensional hyperspectral image as the final three-dimensional hyperspectral image of the target to be measured (1); if they are the same, directly using the three-dimensional hyperspectral image of the target to be measured (1) as the final three-dimensional hyperspectral image of the target to be measured (1).

10. The three-dimensional hyperspectral imaging method according to claim 9, characterized in that: In step 2), the momentum matching and equivalent balance means that the ultrasonic wave simultaneously undergoes acousto-optic interaction with the +1st order diffracted light and the -1st order diffracted light, and the intensities of the two diffracted lights are the same.

Images