A method and imaging system for obtaining single-exposure four-dimensional compressive imaging

Abstract

The present invention relates to a method and an imaging system for obtaining single-exposure four-dimensional compressive imaging; the method includes an object optical signal, performing one-dimensional Fourier transform on the object optical signal to obtain an object dynamic spectral signal, then applying random modulation to obtain an object spectral signal modulation signal, and finally obtaining a two-dimensional compressed image; the system part includes a spectral signal conversion module, a spectral signal modulation module, and a spectral signal compression module. Through the present invention, four-dimensional compressive imaging images can be obtained while considering the time variable.

Description

Technical Field

[0001] The present invention relates to the field of computational optical imaging. Specifically, it relates to a method and an imaging system for obtaining single-exposure four-dimensional compressive imaging. Background Art

[0002] Compressed sensing, also known as compressive sampling, sparse sampling, or compressive sensing, is a new sampling theory. By exploiting the sparse characteristics of signals, it uses random sampling to obtain discrete samples of signals under conditions far less than the Nyquist sampling rate, and then obtains the reconstructed signal through a non-linear reconstruction algorithm.

[0003] Based on the theory of compressed sensing, researchers have developed a high-dimensional imaging technology without scanning, called single-exposure high-dimensional compressive imaging. This technology can obtain three-dimensional information of an object through a single exposure of a two-dimensional compressive detector. For example, in 2007, the hyperspectral imaging system developed by the David J. Brady group at Duke University in the United States could obtain dozens of spectral images of an object through a single exposure of a grayscale camera; in 2014, the ultrafast imaging system reported by the Lihong V. Wang group at Washington University in St. Louis, USA, in the journal Nature used a single exposure of a streak camera to obtain slow-motion videos of light propagation.

[0004] After being improved by the Qiaomu team of the School of Physical Science and Technology at Ningbo University, this technology has been further perfected. As Figure 1 shown, the frame rate compressive imaging technology developed by this research group in 2020 can obtain a dynamic video of up to 50 frames of an object through a single exposure of an ordinary camera. Its core is to use a Digital Micromirror Device (DMD) to perform a random two-dimensional modulation on each frame of the moving image, and finally perform a single exposure measurement on a Charge-coupled Device (CCD) through an optical path to obtain a two-dimensional compressive image of the object to be measured, which is called Coding Aperture Compressive Time Imaging (CACTI).

[0005] As Figure 2It is a tomographic compression imaging system developed by the team in 2021. This system can obtain up to 200 depth slices. This technology has two technical features. One is to use OCT (Optical Coherence Tomography) to convert the three-dimensional information (x, y, z) of an object into a three-dimensional spectral image (x, y, λ). The other is to perform translational modulation on the spectral dimension of the signal light through a dispersion element to achieve the purpose of randomly two-dimensional modulating the three-dimensional spectral image. The specific implementation method is to first divide the signal light into a reference light and a probe light through a Michelson interferometer. The probe light is reflected from different depths of the object and interferes with the reflected reference light. By receiving the signal of the interference light, we convert the three-dimensional stereoscopic information (x, y, z) of the object into spatial spectral data (x, y, λ). Next, the received light intensity information is modulated successively through a fixed mask and a dispersion element (prism or grating). Since the dispersion element will perform translational modulation on the spectral dimension of the signal light, and since the translated random pattern can be equivalent to a new random pattern (i.e., the correlation coefficient with the original pattern is zero), this step of operation is equivalent to applying a random modulation to the spectral dimension as well. Through the above operations, random binary amplitude modulation is applied to the three dimensions of the signal light. Finally, a single exposure measurement is performed through a two-dimensional grayscale detector (CCD) to obtain the two-dimensional compressed image of the object under test. We call this compressed spectral imaging method Encoded Aperture Snapshot Spectral Imaging (CASSI).

[0006] However, the spectral data signal in reality is a function that changes with time. In other words, the spectral data signal should be a function of four-dimensional space-time. Therefore, a method or device that considers the time variable and can obtain a four-dimensional compressed imaging image is needed. Summary of the Invention

[0007] The purpose of the present invention is to overcome the defects of the prior art and provide a method for obtaining single-exposure four-dimensional compressed imaging and an imaging system implemented based on this method.

[0008] A method for obtaining single-exposure four-dimensional compressed imaging provided by the present invention has the following technical solution:

[0009] A method for obtaining single-exposure four-dimensional compressed imaging includes the following steps:

[0010] Step 1: Collect the optical signal data of a specific object within a time interval l, and obtain the object optical signal O(x, y, z, t) with the Cartesian product A of the three-dimensional space region D where the specific object is located and the time interval l as the domain. Among them,

[0011] A = D × l

[0012] (x, y, z) ∈ D represents the position coordinates of any point on the region D where the specific object is located, and t ∈ I is the time variable;

[0013] Step 2: Perform a one-dimensional Fourier transform on the object optical signal O(x, y, z, t) to obtain the object dynamic spectral signal F(x, y, λ, t), where λ is the wavelength parameter;

[0014] Step 3: Apply random modulation simultaneously to the four dimensions of the object dynamic spectral signal F(x, y, λ, t) to obtain the object spectral signal modulation signal G(x, y, λ, t);

[0015] Step 4: Simultaneously compress the spectral dimension and the time dimension of the object spectral signal modulation signal G(x, y, λ, t) through the method of joint integral measurement to obtain the image function Y(x, y);

[0016] Step 5: Output the encoded image represented by the image function Y(x, y) through a computer program to obtain a two-dimensional compressed image.

[0017] Adopting the above technical solution, compared with the prior art, the beneficial effects that the technical solution of the present application can bring at least are: when the spectral data of a mobile phone to an object is obtained, it is possible to convert and modulate the obtained optical signal through the above five basic steps and then perform compression, which not only realizes the image acquisition of four-dimensional compressed imaging under single exposure, but also lays a foundation for the popularization of obtaining compressed imaging with more than four dimensions.

[0018] Preferably, the one-dimensional Fourier transform in Step 2 includes performing the following transformation on the object optical signal O(x, y, z, t);

[0019]

[0020] Among them, F(x, y, λ, t) is the object dynamic spectral signal distribution; it is easy to implement in many optical systems (such as Michelson interferometers), thereby laying a foundation for the implementation of Step 3.

[0021] Preferably, Step 3 includes:

[0022] Step 3.1: Define a random amplitude modulation function M(x, y, λ, t) with the same domain as the object dynamic spectral signal F(x, y, λ, t);

[0023] Step 3.2: Perform a multiplication operation on the object dynamic spectral signal F(x, y, λ, t) and the random amplitude modulation function M(x, y, λ, t)

[0024] G(x, y, λ, t) = F(x, y, λ, t) · M(x, y, λ, t)

[0025] Among them, G(x, y, λ, t) is the modulation signal of the object spectral signal;

[0026] Since the random function M(x, y, λ, t) is a binary function (only has two function values, such as taking 0 and 1), modulating through the random function M(x, y, λ, t) is relatively convenient and simple to operate.

[0027] Preferably, the simultaneous compression of the spectral dimension and time dimension of the object spectral signal modulation signal G(x, y, λ, t) in the fourth step includes performing the following parametric integral on the object spectral signal modulation signal G(x, y, λ, t);

[0028] Y(x, y) = ∫∫G(x, y, λ, t)dλdt

[0029] Among them, the integration region of the integrand G(x, y, λ, t) is (0, +∞) × (0, +∞), and the function Y(x, y) is the image function. In this way, the image function is obtained very naturally. As for the effect of the above integration, relevant books on mathematical physics methods can be referred to, which are omitted here.

[0030] Correspondingly, the technical solution of the present application also provides an image imaging system for obtaining single-exposure four-dimensional compressed imaging, including:

[0031] A spectral signal conversion module for obtaining the object optical signal O(x, y, z, t) and converting the object optical signal O(x, y, z, t) into the object dynamic spectral signal F(x, y, λ, t);

[0032] A spectral signal modulation module for simultaneously applying random modulation to the four dimensions of the object dynamic spectral signal F(x, y, λ, t) to obtain the object spectral signal modulation signal G(x, y, λ, t);

[0033] A spectral signal compression module for simultaneously compressing the spectral dimension and time dimension of the object spectral signal modulation signal G(x, y, λ, t) and obtaining the two-dimensional compressed image;

[0034] The spectral signal modulation module and the spectral signal compression module are arranged in sequence along the propagation direction of the object dynamic spectral signal F(x, y, λ, t) obtained by the spectral signal conversion module.

[0035] Adopting the above technical solution, compared with the prior art, the beneficial effects that the technical solution of the present application can bring at least include: obtaining the required spectral signal through the spectral signal conversion module, performing random modulation through the spectral signal modulation module, and finally obtaining the final two-dimensional compressed image in the spectral signal compression module. While fully respecting the physical laws, combined with the requirements of the above method for obtaining a single-exposure four-dimensional compressed imaging image, the difficulty of obtaining a single-exposure four-dimensional compressed imaging image is overcome.

[0036] Preferably, the spectral signal conversion module includes an illumination light source, an achromatic lens AL1, a low-pass filter LPF, a high-pass filter HPF, an achromatic lens AL2, a beam splitter BS, an objective lens OL1, a reflector, an objective lens OL2, and a dynamic object; the achromatic lens AL1, the low-pass filter LPF, the high-pass filter HPF, the achromatic lens AL2, and the beam splitter BS are sequentially arranged along the propagation direction of the illumination light output by the illumination light source. The beam splitter divides the illumination light into a reference light and a detection light. The objective lens OL1 and the reflector are sequentially arranged along the propagation direction of the reference light; the objective lens OL2 and the dynamic object are sequentially arranged along the propagation direction of the detection light; after the reference light and the detection light are respectively reflected by the reflector and the dynamic three-dimensional dynamic object, they recombine at the beam splitter BS to interfere and form a signal light, and the signal light is the object dynamic spectral signal F(x, y, λ, t); in this way, not only the acquisition of the spectral signal is realized, but also the conversion of the spectral signal is realized, and the structure is simple and the cost is low.

[0037] Preferably, the distance between the objective lens OL1 and the reflector is the same as the focal length of the objective lens OL1, and the distance between the objective lens OL2 and the dynamic object is the same as the focal length of the objective lens OL2; this can ensure that the light does not form an image when passing through the relevant lenses, thus ensuring the smoothness of the optical path.

[0038] Preferably, an optical fiber is arranged between the illumination light source and the achromatic lens AL1. The distance from the outlet A of the optical fiber to the achromatic lens AL1 is the same as the focal length of the achromatic lens AL1, and the other end of the optical fiber is connected to the illumination light source; this can ensure the smooth transmission of the illumination light to the achromatic lens AL1 and prevent imaging.

[0039] Preferably, the spectral signal modulation module includes a random modulation optical signal unit and a translation modulation optical signal unit. The random modulation optical signal unit and the translation modulation optical signal unit are arranged in sequence along the propagation direction of the object dynamic spectral signal F(x, y, λ, t). The random modulation optical signal unit is configured to convert the object dynamic spectral signal F(x, y, λ, t) into a random modulation optical signal and transmit it to the translation modulation optical signal unit. The translation modulation optical signal unit is configured to perform translation modulation on the random modulation optical signal to form the object spectral signal modulation signal G(x, y, λ, t). This ensures joint spatial modulation, temporal modulation, and spectral modulation, and applies random modulation to the four dimensions of the object dynamic spectral signal F(x, y, λ, t) simultaneously.

[0040] Preferably, the random modulation optical signal unit includes a sleeve lens TL1, a prism 1, and a digital micromirror device DMD. The sleeve lens TL1, the prism 1, and the digital micromirror device DMD are arranged in sequence along the propagation direction of the object dynamic spectral signal F(x, y, λ, t). The object dynamic spectral signal F(x, y, λ, t) is randomly modulated by the digital micromirror device DMD to form a random modulation optical signal. In this way, by using the previous digital micromirror device DMD and based on the frame rate compression imaging technology, random modulation is achieved at a relatively low cost.

[0041] Preferably, the translation modulation optical signal unit includes a prism 2, an objective lens OL3, and a grating. The prism 2, the objective lens OL3, and the grating are arranged in sequence along the propagation direction of the random modulation optical signal. The random modulation optical signal performs translation modulation on the spectral dimension through the grating to form the object spectral signal modulation signal G(x, y, λ, t). The translation modulation of the random modulation optical signal is achieved through the grating, and a high-quality object spectral signal modulation signal G(x, y, λ, t) is obtained.

[0042] Preferably, the distance between the sleeve lens TL1 and the digital micromirror device DMD is the same as the focal length of the sleeve lens TL1, and the distance between the digital micromirror device DMD and the objective lens OL3 is the same as the focal length of the objective lens OL3. This is to ensure smooth optical paths.

[0043] Preferably, the spectral signal compression module includes a sleeve lens TL2 and a two-dimensional grayscale detector CCD. The sleeve lens TL2 and the two-dimensional grayscale detector CCD are arranged in sequence along the propagation direction of the object spectral signal modulation signal G(x, y, λ, t). The object spectral signal modulation signal G(x, y, λ, t) is subjected to single-exposure mapping through the two-dimensional grayscale detector CCD to obtain the two-dimensional compressed image. The distance between the sleeve lens TL2 and the two-dimensional grayscale detector CCD is equal to the focal length of the sleeve lens TL2. Accordingly, the acquisition of the two-dimensional compressed image is realized. Description of the Drawings

[0044] Figure 1 It is the encoded image of a moving object captured by the detector of the "single-exposure time compression imaging technology" developed by the Qiaomu team in the early stage;

[0045] Figure 2 It is the encoded image of a three-dimensional object captured by the detector of the "single-exposure stereoscopic imaging technology" developed by the Qiaomu team in the early stage;

[0046] Figure 3 It is a flowchart of a method for obtaining a single-exposure four-dimensional compressed imaging image in the present invention;

[0047] Figure 4 It is a structural diagram of an image imaging system for obtaining a single-exposure four-dimensional compressed imaging image in the present invention;

[0048] Figure 5 An optical path diagram of an image imaging system for obtaining a single-exposure four-dimensional compressed imaging image in the present invention. Detailed Embodiments

[0049] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0050] Combined with Figure 1 —5, in this embodiment, a detailed introduction will be given to a method and an imaging system for obtaining a single-exposure four-dimensional compressed imaging image in the present invention.

[0051] A method for obtaining a single-exposure four-dimensional compressed imaging image provided by an embodiment of the present invention includes the following steps:

[0052] Step 1: Collect optical signal data of a specific object within a time interval l, and obtain an object optical signal O(x, y, z, t) with the Cartesian product A of the three-dimensional space region D where the specific object is located and the time interval l as the domain, where

[0053] A = D × 1

[0054] (x, y, z) ∈ D represents the position coordinates of any point on the region D where the specific object is located, and t ∈ I is the time variable.

[0055] The optical signal data can be obtained through signal acquisition, and then the object optical signal O(x, y, z, t) can be obtained through numerical calculation methods.

[0056] Step 2: Perform a one-dimensional Fourier transform on the object optical signal O(x, y, z, t) to obtain the object dynamic spectral signal F(x, y, λ, t); the one-dimensional Fourier transform in this embodiment is to perform the following transformation on the object optical signal O(x, y, z, t);

[0057]

[0058] Among them, F(x, y, λ, t) is the object dynamic spectral signal distribution, and λ is the wavelength parameter.

[0059] Step 3: Apply random modulation to the four dimensions of the object dynamic spectral signal F(x, y, λ, t) simultaneously to obtain the object spectral signal modulation signal G(x, y, λ, t).

[0060] Specifically, this step is achieved through the following two basic steps:

[0061] Step 3.1: Define a random amplitude modulation function M(x, y, λ, t) with the same domain as the object dynamic spectral signal F(x, y, λ, t). In this embodiment, a random amplitude modulation function M(x, y, λ, t) with values of 0 and 1 is used;

[0062] Step 3.2: Perform a multiplication operation on the object dynamic spectral signal F(x, y, λ, t) and the random amplitude modulation function M(x, y, λ, t)

[0063] G(x, y, λ, t) = F(x, y, λ, t) · M(x, y, λ, t)

[0064] Among them, G(x, y, λ, t) is the object spectral signal modulation signal.

[0065] Step 4: Through the method of joint integral measurement, compress the spectral dimension and time dimension of the object spectral signal modulation signal G(x, y, λ, t) simultaneously to obtain the image function Y(x, y).

[0066] Specifically, the simultaneous compression of the spectral dimension and time dimension of the object spectral signal modulation signal G(x, y, λ, t) in this embodiment is to perform the following integral with a parameter variable on the object spectral signal modulation signal G(x, y, λ, t);

[0067] Y(x,y) = ∫∫G(x,y,λ,t)dλdt

[0068] where the integration region of the integrand G(x,y,λ,t) is (0, +∞)×(0, +∞), and the function Y(x,y) is the image function.

[0069] Step Five: Output the encoded image represented by the image function Y(x,y) through a computer program to obtain a two-dimensional compressed image, which is specifically realized through computer simulation.

[0070] Meanwhile, this embodiment also provides an image imaging system for obtaining single-exposure four-dimensional compressed imaging, including:

[0071] A spectral signal conversion module for obtaining the object optical signal O(x,y,z,t) and converting the object optical signal O(x,y,z,t) into the object dynamic spectral signal F(x,y,λ,t);

[0072] A spectral signal modulation module for simultaneously applying random modulation to the four dimensions of the object dynamic spectral signal F(x,y,λ,t) to obtain the object spectral signal modulation signal G(x,y,λ,t);

[0073] A spectral signal compression module for simultaneously compressing the spectral dimension and the time dimension of the object spectral signal modulation signal G(x,y,λ,t) and obtaining the two-dimensional compressed image;

[0074] The spectral signal modulation module and the spectral signal compression module are sequentially arranged along the propagation direction of the object dynamic spectral signal F(x,y,λ,t) obtained by the spectral signal conversion module.

[0075] In this embodiment, the spectral signal conversion module includes an illumination light source, an achromatic lens AL1, a low-pass filter LPF, a high-pass filter HPF, an achromatic lens AL2, a beam splitter BS, an objective lens OL1, a reflector, an objective lens OL2, and a dynamic object; the achromatic lens AL1, the low-pass filter LPF, the high-pass filter HPF, the achromatic lens AL2, and the beam splitter BS are sequentially arranged along the propagation direction of the illumination light output by the illumination light source. The beam splitter divides the incoming illumination light into a reference light and a detection light. The objective lens OL1 and the reflector are sequentially arranged along the propagation direction of the reference light; the objective lens OL2 and the dynamic object are sequentially arranged along the propagation direction of the detection light; the reference light and the detection light are respectively reflected by the reflector and the dynamic three-dimensional dynamic object and then enter the beam splitter BS, and are recombined at the beam splitter BS to form an interference signal light, and the signal light is the object dynamic spectral signal F(x,y,λ,t). This process uses the idea of a Michelson interferometer for signal conversion.

[0076] In this embodiment, the distance between the objective lens OL1 and the mirror is equal to the focal length of the objective lens OL1, and the distance between the objective lens OL2 and the dynamic object is equal to the focal length of the objective lens OL2. An optical fiber is arranged between the illumination light source and the achromatic lens AL1, and the distance from the fiber outlet A to the achromatic lens AL1 is equal to the focal length of the achromatic lens AL1. The other end of the optical fiber is connected to the illumination light source.

[0077] In this embodiment, the spectral signal modulation module includes a random modulation optical signal unit and a translational modulation optical signal unit. The random modulation optical signal unit and the translational modulation optical signal unit are arranged in sequence along the propagation direction of the object dynamic spectral signal F(x, y, λ, t). The random modulation optical signal unit is configured to convert the object dynamic spectral signal F(x, y, λ, t) into a random modulation optical signal and transmit it to the translational modulation optical signal unit. The translational modulation optical signal unit is configured to perform translational modulation on the random modulation optical signal to finally form the object spectral signal modulation signal G(x, y, λ, t).

[0078] In this embodiment, the random modulation optical signal unit includes a sleeve lens TL1, a prism 1, and a digital micromirror device DMD. The sleeve lens TL1, the prism 1, and the digital micromirror device DMD are arranged in sequence along the propagation direction of the object dynamic spectral signal F(x, y, λ, t). The object dynamic spectral signal F(x, y, λ, t) is randomly modulated and reflected by the digital micromirror device DMD to form a random modulation optical signal.

[0079] In this embodiment, the translational modulation optical signal unit includes a prism 2, an objective lens OL3, and a grating. The prism 2, the objective lens OL3, and the grating are arranged in sequence along the propagation direction of the random modulation optical signal. The random modulation optical signal performs translational modulation on the spectral dimension through the grating to form the object spectral signal modulation signal G(x, y, λ, t). At the same time, the distance between the sleeve lens TL1 and the digital micromirror device DMD is equal to the focal length of the sleeve lens TL1, and the distance between the digital micromirror device DMD and the objective lens OL3 is equal to the focal length of the objective lens OL3.

[0080] In this embodiment, the spectral signal compression module includes a sleeve lens TL2 and a two-dimensional grayscale detector CCD. The sleeve lens TL2 and the two-dimensional grayscale detector CCD are arranged in sequence along the propagation direction of the object spectral signal modulation signal G(x, y, λ, t). The object spectral signal modulation signal G(x, y, λ, t) is subjected to single-exposure mapping by the two-dimensional grayscale detector CCD to obtain a two-dimensional compressed image. Moreover, the distance between the sleeve lens TL2 and the two-dimensional grayscale detector CCD is equal to the focal length of the sleeve lens TL2.

[0081] The object optical signal O(x, y, z, t) can be a reflectivity or other optical luminescence signal. When applying random modulation to the four dimensions of the object dynamic spectral signal F(x, y, λ, t) simultaneously using the spectral signal modulation module in the technical solution of the present application, only the random modulation optical signal unit can be used for random modulation. Generally, a superluminescent diode (SLD) can be used as the light source, which can improve the efficiency.

[0082] In summary, although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to the embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for obtaining single-exposure four-dimensional compressed imaging, characterized in that: It includes the following steps: Step 1: Collect optical signal data of a specific object within a time interval l, and obtain the object optical signal O(x, y, z, t) with the Cartesian product A of the three-dimensional space region D where the specific object is located and the time interval l as the domain. Among them, A = D × 1 (x, y, z) ∈ D is the position coordinate of any point on the region D where the specific object is located, and t ∈ I is the time variable; Step 2: Perform one-dimensional Fourier transform on the object optical signal O(x, y, z, t) to obtain the object dynamic spectral signal F(x, y, λ, t), where λ is the wavelength parameter; Step 3: Randomly modulate the object dynamic spectral signal F(x, y, λ, t) to obtain the object spectral signal modulation signal G(x, y, λ, t); Step 4: By means of integration, compress the spectral dimension and time dimension of the object spectral signal modulation signal G(x, y, λ, t) simultaneously to obtain the image function Y(x, y); Step 5: Output the encoded image represented by the image function Y(x, y) through a computer program to obtain a two-dimensional compressed image.

2. The method for obtaining single-exposure four-dimensional compressed imaging according to claim 1, characterized in that: The one-dimensional Fourier transform in step 2 includes performing the following transformation on the object optical signal O(x, y, z, t); Among them, F(x, y, λ, t) is the object dynamic spectral signal distribution.

3. The method for obtaining single-exposure four-dimensional compressed imaging according to claim 2, characterized in that: Step 3 includes: Step 3.1: Develop a random amplitude modulation function M(x, y, λ, t) with the same domain as the object dynamic spectral signal F(x, y, λ, t); Step 3.2: Perform a multiplication operation on the object dynamic spectral signal F(x, y, λ, t) and the random amplitude modulation function M(x, y, λ, t), and let G(x, y, λ, t) = F(x, y, λ, t) × M(x, y, λ, t) Among them, G(x, y, λ, t) is the object spectral signal modulation signal.

4. The method for obtaining single-exposure four-dimensional compressed imaging according to claim 3, characterized in that: In step 4, simultaneously compressing the spectral dimension and time dimension of the object spectral signal modulation signal G(x, y, λ, t) includes performing the following parametric integral on the object spectral signal modulation signal G(x, y, λ, t); Y(x, y) = ∫∫G(x, y, λ, t)dλdt Among them, the integration region of the integrand G(x, y, λ, t) is (0, +∞) × (0, +∞), and the function Y(x, y) is the image function.

5. An image imaging system for obtaining single-exposure four-dimensional compressed imaging, characterized in that: Based on the method for obtaining single-exposure four-dimensional compressed imaging described in any one of claims 1-4, it includes: A spectral signal conversion module for acquiring the optical signal O(x, y, z, t) of the object and converting the optical signal O(x, y, z, t) of the object into the dynamic spectral signal F(x, y, λ, t) of the object; A spectral signal modulation module for simultaneously applying random modulation to four dimensions of the dynamic spectral signal F(x, y, λ, t) of the object to obtain the spectral signal modulation signal G(x, y, λ, t) of the object spectral signal; A spectral signal compression module for simultaneously compressing the spectral dimension and the time dimension of the spectral signal modulation signal G(x, y, λ, t) of the object and obtaining the spectral signal compression of the two-dimensional compressed image; The spectral signal modulation module and the spectral signal compression module are sequentially arranged along the propagation direction of the dynamic spectral signal F(x, y, λ, t) of the object acquired by the spectral signal conversion module.

6. The image imaging system for obtaining single-exposure four-dimensional compressed imaging according to claim 5, wherein: The spectral signal conversion module includes an illumination light source, an achromatic lens AL1, a low-pass filter LPF, a high-pass filter HPF, an achromatic lens AL2, a beam splitter BS, an objective lens OL1, a reflector, an objective lens OL2, and a dynamic object; the illumination light source outputs illumination light, and the achromatic lens AL1, the low-pass filter LPF, the high-pass filter HPF, the achromatic lens AL2, and the beam splitter BS are sequentially arranged along the propagation direction of the illumination light. The beam splitter divides the incident illumination light into a reference light and a detection light. The objective lens OL1 and the reflector are sequentially arranged along the propagation direction of the reference light; the objective lens OL2 and the dynamic object are sequentially arranged along the propagation direction of the detection light. After the reference light and the detection light are respectively reflected by the reflector and the dynamic object, they are recombined at the beam splitter BS to interfere to form a signal light, and the signal light is the dynamic spectral signal F(x, y, λ, t) of the object.

7. The image imaging system for obtaining single-exposure four-dimensional compressed imaging according to claim 6, wherein: The distance between the objective lens OL1 and the reflector is the same as the focal length of the objective lens OL1, and the distance between the objective lens OL2 and the dynamic object is the same as the focal length of the objective lens OL2.

8. The image imaging system for obtaining single-exposure four-dimensional compressed imaging according to claim 7, wherein: An optical fiber is arranged between the illumination light source and the achromatic lens AL1. The distance from the outlet A of the optical fiber to the achromatic lens AL1 is the same as the focal length of the achromatic lens AL1, and the other end of the optical fiber is connected to the illumination light source.

9. The image imaging system for obtaining single-exposure four-dimensional compressed imaging according to claim 8, wherein: The spectral signal modulation module includes a random modulation optical signal unit and a translation modulation optical signal unit. The random modulation optical signal unit and the translation modulation optical signal unit are arranged in sequence along the propagation direction of the object dynamic spectral signal F(x, y, λ, t). The random modulation optical signal unit is configured to convert the object dynamic spectral signal F(x, y, λ, t) into a random modulation optical signal and transmit it to the translation modulation optical signal unit. The translation modulation optical signal unit is configured to perform translation modulation on the random modulation optical signal to form the object spectral signal modulation signal G(x, y, λ, t).

10. The image imaging system for obtaining single-exposure four-dimensional compressed imaging according to claim 9, wherein: The random modulation optical signal unit includes a sleeve lens TL1, a prism 1, and a digital micromirror device DMD. The sleeve lens TL1, the prism 1, and the digital micromirror device DMD are arranged in sequence along the propagation direction of the object dynamic spectral signal F(x, y, λ, t). The object dynamic spectral signal F(x, y, λ, t) forms a random modulation optical signal after random modulation by the digital micromirror device DMD.

11. The image imaging system for obtaining single-exposure four-dimensional compressed imaging according to claim 10, wherein: The translation modulation optical signal unit includes a prism 2, an objective lens OL3, and a grating. The prism 2, the objective lens OL3, and the grating are arranged in sequence along the propagation direction of the random modulation optical signal. The propagation direction of the random modulation optical signal performs translation modulation on the spectral dimension through the grating to form the object spectral signal modulation signal G(x, y, λ, t).

12. The image imaging system for obtaining single-exposure four-dimensional compressed imaging according to claim 11, wherein: The distance between the sleeve lens TL1 and the digital micromirror device DMD is the same as the focal length of the sleeve lens TL1, and the distance between the digital micromirror device DMD and the objective lens OL3 is the same as the focal length of the objective lens OL3.

13. The image imaging system for obtaining single-exposure four-dimensional compressed imaging according to claim 12, wherein: The spectral signal compression module includes a sleeve lens TL2 and a two-dimensional grayscale detector CCD. The sleeve lens TL2 and the two-dimensional grayscale detector CCD are arranged in sequence along the propagation direction of the object spectral signal modulation signal G(x, y, λ, t). The object spectral signal modulation signal G(x, y, λ, t) is subjected to single-exposure mapping by the two-dimensional grayscale detector CCD to obtain the two-dimensional compressed image; the distance between the sleeve lens TL2 and the two-dimensional grayscale detector CCD is the same as the focal length of the sleeve lens TL2.

Images