High-resolution fast compressed sensing single photon array imaging system and method

Abstract

The invention discloses a high-resolution fast compressed sensing single photon array imaging system and method, and relates to the technical field of weak light imaging and computational imaging. The system comprises an imaging light source, an optical attenuator, a light beam expander, a to-be-detected target, a signal generator, a spatial light modulator, a single photon detection array, a counting storage module and a data processing module. Wherein the imaging light source is used for emitting a light beam to illuminate a target scene to be imaged; the optical attenuator, the light beam expander, the target to be measured and the spatial light modulator are sequentially arranged on a transmission light path of a light beam; the signal generator is respectively connected with the spatial light modulator and the single photon detection array; and the single photon detection array, the counting storage module and the data processing module are connected in sequence. According to the invention, the problem that the measurement mask is difficult to manufacture and store due to overlarge reconstruction resolution can be solved, and the imaging resolution and the imaging rate are improved.

Description

Technical Field

[0001] The present invention relates to the technical fields of weak-light imaging and computational imaging, and in particular to a high-resolution fast compressed sensing single-photon array imaging system and method. Background Art

[0002] Single-photon imaging technology is a new type of imaging technology with a single-photon-level detection sensitivity limit, which can realize the perception of extremely weak optical signals. Traditional optical imaging technology is limited by factors such as detection sensitivity and dynamic range, and can no longer meet the effective identification of imaging targets. The emergence of single-photon imaging technology can make up for the many shortcomings of traditional optical imaging technology. However, the existing single-photon imaging technology is difficult to take into account both high detection rate and fast imaging rate at the same time. With the rapid development of modern science and technology, the development of single-photon imaging technology for fast imaging and high-definition imaging should become the current key research direction.

[0003] Single-pixel imaging is a new imaging technology proposed in recent years. This technology uses only a bucket detector without spatial resolution and a spatially encodable modulator to form a single-pixel imaging system, which compresses the pixel size of the imaging detector to the limit. In particular, due to the high cost brought by the immaturity of array sensor technology, single-pixel detectors have become the mainstream optical detectors in the field of low-light imaging due to their cost advantages and photosensitivity. However, the technical bottleneck of single-pixel imaging is still an unresolved problem, that is, the imaging rate has always been at a relatively slow level, and this solution is difficult to apply to dynamic scenes for imaging. The reason is that the main factor affecting the single-pixel imaging rate is the refresh rate of the spatial light modulation module. Even if the current more advanced spatial light modulation module is used, its modulation rate can only reach a maximum of 22KHz. Obviously, with the improvement of imaging resolution requirements, the number of measurement masks required is bound to increase by several orders of magnitude. This not only places high demands on the spatial light modulation module for mask loading and storage, but also the limitation of device refresh rate determines that the imaging rate at high resolution is difficult to break through according to the previous mode. Even if the compressed sensing technology is integrated for signal sub-sampling, the number of measurement masks can be reduced to a certain extent, thereby indirectly improving the imaging rate, but it is still difficult to solve the fast imaging requirements under high resolution requirements.

[0004] In summary, although single-pixel imaging technology has advantages due to its low cost, wide spectral detection range and high sensitivity, it is limited to the modulation rate of structured light encoding in the spatial light modulation module. In the face of high-resolution imaging and fast imaging requirements, even if compressed sensing technology is used for sub-sampling signal processing, it cannot meet the requirements of high-resolution image reconstruction in a short time. Summary of the invention

[0005] The purpose of the present invention is to provide a high-resolution fast compressed sensing single-photon array imaging system and method, which can solve the problem that the measurement mask is difficult to produce and store when the reconstruction resolution is too large, and improve the imaging resolution and imaging rate.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A high-resolution, fast compressed sensing single-photon array imaging system, comprising: an imaging light source, an optical attenuator, an optical beam expander, a target to be measured, a signal generator, a spatial light modulator, a single-photon detection array, a counting storage module and a data processing module;

[0008] The imaging light source is used to emit a light beam to illuminate the target scene to be imaged; the light attenuator, the light beam expander, the target to be measured and the spatial light modulator are sequentially arranged on the transmission light path of the light beam; the signal generator is respectively connected to the spatial light modulator and the single photon detection array; the single photon detection array, the counting storage module and the data processing module are sequentially connected;

[0009] The optical attenuator is used to attenuate the light intensity to a single photon level to prevent damage caused by excessive light intensity;

[0010] The optical beam expander is used to appropriately expand the attenuated light beam to meet the lighting requirements;

[0011] The signal generator is used to provide an external clock source to synchronize data acquisition between the spatial light modulator and the single photon detection array;

[0012] The spatial light modulator is used to load a binary measurement mask, and the trigger signal sent during the modulation process also establishes a synchronous measurement with the single photon detection array;

[0013] The single photon detection array is used to sequentially acquire the photon count distribution corresponding to each measurement mask based on the trigger signal sent by the spatial light modulation device, and to collect the photon count distribution of multiple pixels in parallel;

[0014] The counting storage module is used to perform data classification and parallel storage on the photon counting values ​​in the multi-pixel region set;

[0015] The data processing module is used to use the stored photon count distribution data and the spatial distribution corresponding to the mask as data input of the compressed sensing algorithm, perform an approximate one-norm solution, and reconstruct the instantaneous image of the target to be measured.

[0016] Optionally, the imaging light source adopts a 532nm laser.

[0017] The present invention also provides a high-resolution fast compressed sensing single-photon array imaging method, based on the above system, comprising:

[0018] generating a binary coded measurement matrix for loading onto a spatial light modulator;

[0019] Loading the binary coded measurement matrix into the spatial light modulation module to perform spatial light modulation coding;

[0020] The image signal of each base mask area is reconstructed by block compression sensing, and the final target scene image is obtained by splicing; each base mask area is composed of base binary codes.

[0021] Optionally, the generating of the binary coded measurement matrix for loading onto the spatial light modulator specifically includes: setting the size of the basis measurement matrix to be m×n, and generating an initial binary coded measurement matrix Φ with a size of m×n, setting all elements of the initial binary coded measurement matrix Φ to be 0 or 1, Φ i,j ∈{0,1}, i and j are the element distributions under the binary coding measurement matrix, and a total of K measurement matrices that meet the above conditions are generated. K different measurement matrices are spliced ​​into a new binary coding measurement matrix Φ according to N×N blocks. K , {Φ K |K=1,2,…,K}, where N is the number of blocks, and the final imaging resolution is the number of blocks N multiplied by the size of the basis measurement matrix m×n.

[0022] Optionally, the binary coding measurement matrix is ​​generated as follows:

[0023] According to the imaging resolution, the base mask matrix size is determined, the required imaging resolution is divided into N×N according to the base mask size, and a Hadamard matrix of the same order is generated according to the base mask size;

[0024] The generated Hadamard matrix is ​​differentially calculated to obtain a binary measurement matrix whose values ​​are only 0 and 1. The individual rows of the Hadamard matrix are extracted to reorganize it into a square matrix with the size of the base mask. The same base mask matrix is ​​spliced ​​into N×N blocks, and the size of the mask matrix is ​​adjusted by adding zeros around it. Finally, a mask matrix that meets the resolution of the spatial light modulation module is obtained.

[0025] Optionally, the new binary coding measurement matrix corresponds to K binary coding masks, and an all-zero mask needs to be added before the first mask and after the Kth mask as a start and stop mark mask, generating a total of K+2 mask patterns.

[0026] Optionally, the loading of the binary coded measurement matrix into the spatial light modulation module to perform spatial light modulation coding specifically includes:

[0027] The binary coded measurement matrix is ​​loaded onto the spatial light modulator. During the process of the imaging light source irradiating the target to be measured, some photons reach the spatial light modulator due to scattering, and according to the initial modulation frequency, the loaded binary coded measurement matrix is ​​used to perform spatial coding modulation on the target photons. At the same time, the spatial light modulator sends a trigger signal after the modulation cycle ends. When the single photon detection array receives the trigger signal, it performs K photon number detection on the modulated photons. Since the single photon detection array uses a multi-pixel detection method, the block binary coded measurement matrix is ​​divided into blocks according to the block area N. 2 The single photon detection array counts the photons in blocks independently, and the final photon count is expressed as n N2×K .

[0028] Optionally, the specific calculation process of the photon counting is:

[0029] Set the spatial light modulator to single play, the number of mask frames of the spatial light modulator is K+2, and the play frame rate B of the spatial light modulator is set according to the exposure time of the single photon detection array;

[0030] The masks corresponding to all binary coded measurement matrices are loaded onto the spatial light modulator, and the spatial light modulator performs spatial light coding modulation on the target to be measured according to 1 / B as the modulation period, and the modulated photons are received by the single photon detection array;

[0031] The spatial light modulation module sends a trigger signal every 1 / B modulation cycles. The single-photon detection array receives the trigger signal, synchronously samples the modulated photons, and performs photon counting statistics in parallel and independently according to the N×N different block areas in the binary measurement matrix sequence. Finally, the photon count value n of each area is calculated. N2×K .

[0032] Optionally, the block-by-block reconstruction of the image signal of each base mask area by using compressed sensing and obtaining the final target scene image by splicing specifically includes:

[0033] According to the spatial structure of the binary coded measurement matrix, each independent measurement matrix is ​​composed of N×N identical base binary coded measurement matrices, and performs parallel independent spatial light modulation tasks. The single photon detection array collects the photon counts of each area in parallel in blocks. N2×K After completing a detection cycle, the photon counts of each area of ​​the block are summed up and expressed by y N2×K Indicates that the spatial structure of the binary coding measurement matrix is ​​represented by Φ K According to the compressed sensing measurement process, the expression is given: N2×K =ΦK X, where X is the signal to be reconstructed, x represents the original signal to be reconstructed in each block area. Each reconstructed x is reassembled and spliced ​​according to N×N to obtain the final target scene image.

[0034] Optionally, the target scene image is reconstructed as follows:

[0035] The single-photon detection array counts the number of photons detected in each base mask block area N. 2 ×K is the measurement value y in the compressed sensing algorithm;

[0036] The binary coded measurement matrix Φ K As the measurement matrix in compressed sensing, Φ K The number of rows M represents the number of measurements, which is equal to the number of masks K loaded into the spatial light modulation module, and the number of columns is the total number of pixels in the base measurement matrix;

[0037] Based on the measurement value y and the binary coded measurement matrix Φ K To perform compressed sensing measurements, use the expression Reconstruct, where X is the signal to be reconstructed, x represents the original signal to be reconstructed in each block area. Each reconstructed x is reassembled and spliced ​​according to N×N to obtain the final target scene image.

[0038] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0039] The present invention discloses a high-resolution fast compressed sensing single-photon array imaging system and method, the system includes an imaging light source, an optical attenuator, an optical beam expander, a target to be measured, a signal generator, a spatial light modulator, a single-photon detection array, a counting storage module and a data processing module; wherein the imaging light source is used to emit a light beam to illuminate the target scene to be imaged; the optical attenuator, the optical beam expander, the target to be measured and the spatial light modulator are sequentially arranged on the transmission optical path of the light beam; the signal generator is respectively connected to the spatial light modulator and the single-photon detection array; the single-photon detection array, the counting storage module and the data processing module are sequentially connected. The present invention can solve the problem that the measurement mask is difficult to make and store when the reconstruction resolution is too large, and improves the imaging resolution and imaging rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0041] Figure 1 It is a schematic diagram of the structure of the high-resolution fast compressed sensing single-photon array imaging system of the present invention;

[0042] Figure 2 The photon count distribution diagram obtained by the single photon array in this embodiment for a block area as the modulation mask changes;

[0043] Figure 3 This is a result diagram obtained by taking the imaging resolution plate as the object in this embodiment and using the imaging scheme combined with photon correlation statistics;

[0044] Figure 4 Graphs showing signal-to-noise ratios of the single-photon array measured at different photon counting intensities in this embodiment.

[0045] Figure numerals: 1. imaging light source; 2. light attenuator; 3. light beam expander; 4. target to be measured; 5. signal generator; 6. spatial light modulator; 7. single photon detection array; 8. counting storage module; 9. data processing module. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] The purpose of the present invention is to provide a high-resolution fast compressed sensing single-photon array imaging system and method, which can solve the problem that the measurement mask is difficult to produce and store when the reconstruction resolution is too large, and improve the imaging resolution and imaging rate.

[0048] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] like Figure 1As shown, the present invention provides a high-resolution fast compressed sensing single-photon array imaging system, including: an imaging light source 1, an optical attenuator 2, an optical beam expander 3, a target to be measured 4, a signal generator 5, a spatial light modulator 6, a single-photon detection array 7, a counting storage module 8 and a data processing module 9.

[0050] The imaging light source 1 adopts a 532nm laser, one end of which is coupled to the output by a single-mode optical fiber, so that the emitted light beam has a smaller divergence angle; the optical attenuator 2 is arranged after the 532nm laser, and is used to quickly attenuate the laser power to within the working range of the single-photon array detector; the optical beam expander 3 is placed after the optical attenuator 2, and is used to appropriately amplify the attenuated light beam spot, so that the spot size fills the entire micromirror array modulation surface of the spatial light modulator 6 as much as possible; the spatial light modulator 6 performs spatial modulation on the scattered photons on the imaging target according to the loaded binary modulation mask sequence Optical structure encoding, the coded modulated photons are incident into the single-photon array detector; the multiple pixel detection units in the single-photon array detector are divided into blocks, and the block area is consistent with the mask block area N×N loaded in the spatial light modulator 6. The single-photon detection units in the N×N block areas count the incident photons independently and in parallel. According to the trigger signal sent by the spatial light modulator 6 after each mask modulation cycle, the single-photon detection array 7 receives the synchronous trigger signal and counts the photons of the N×N block areas of the K masks in turn; the counting storage module 8 is used to count the photons n N2×K Data storage; the data processing module 9 is used to use the statistical photon counting information and the spatial structure information of the modulation mask as known quantities for compressed sensing reconstruction, and sequentially perform compressed sensing reconstruction on N×N block areas to obtain corresponding scene block reconstructed images, and then perform orderly splicing to obtain the final reconstructed high-resolution scene imaging.

[0051] Figure 2 The photon count distribution diagram is obtained by statistically analyzing one of the block regions of the N×N block modulation mask of the spatial light modulator 6 in the embodiment of the present invention as the modulation mask sequence changes. Since the base modulation mask adopts the Hadamard matrix, the photon count distribution presented in the final experiment is Figure 2 shown.

[0052] An imaging method is provided based on the above-mentioned single photon array imaging system, and the steps are as follows:

[0053] S1. Generate a binary coded measurement matrix for loading onto the six spatial light modulators, and achieve different spatial light structure encoding of the imaging scene by fast modulation of different masks by the six spatial light modulators. The specific generation method is as follows:

[0054] S1-1. Set the size of the basis binary measurement matrix, such as using 128×128 as the size of the basis binary measurement matrix m×n.

[0055] S1-2. Generate a base binary measurement matrix sequence Φ, and generate a Hadamard matrix of the same order as the base binary measurement matrix. For example, in the case of 128×128 size, 128 2 ×128 2 The Hadamard matrix of .

[0056] S1-3. The basis Hadamard matrix is ​​optimized and sorted for differential processing. Since the Hadmard matrix consists of elements -1 and +1, it cannot be directly loaded into the spatial light modulation module. The differential processing can change the matrix element values ​​to 0 and 1. The optimized and sorted Hadamard matrix is ​​more in line with the sampling characteristics under natural conditions, making the final reconstruction of the original signal better. The individual rows of the Hadamard matrix after differential optimization and sorting are extracted in turn and recombined into a basis binary measurement matrix sequence that conforms to the size of 128×128.

[0057] S1-4. Set the required imaging resolution size, such as setting the required imaging resolution to 512×512.

[0058] S1-5. Determine the size N of the block area required for measuring the mask. The value of N depends on the ratio between the imaging resolution and the size of the base mask. Under the above conditions, the value of N is 512 / 128, and the required block area is 8×8.

[0059] S1-6. Splice the base binary measurement matrix into blocks according to the block area N×N to obtain K new binary measurement matrix mask sequences Φ K , {Φ K |K=1,2,…,K}.

[0060] S2, load the binary coded measurement matrix sequence Φ K To the spatial light modulation module, the spatial light structure encoding of the scene to be imaged is performed. The specific method is as follows:

[0061] S2-1. Set the spatial light modulation module to single play mode, and load K binary measurement matrix masks into the spatial light modulation module one by one.

[0062] S2-2. According to the exposure time of the single-photon detector, select an appropriate modulation frequency. The playback dwell time of each mask is the detection cycle.

[0063] S2-3. The spatial light modulation module encodes the spatial light structure of scattered photons from the scene to be imaged that are illuminated by the imaging light source 1 and reach the spatial light modulation area according to the different mask structure patterns loaded, and sends out a trigger signal at the end of each mask detection cycle.

[0064] S2-4. The encoded photons are synchronously received by the photon collection module along with the trigger signal, and the single-photon detector counts single photons in parallel and independently in each base mask area in the mask block area N×N, and counts N 2 Photon counts n N2×K .

[0065] S3, using compressed sensing to reconstruct the image signal of each base mask area in blocks, reducing redundant data collection, achieving subsampling during the measurement process, and further improving the imaging rate. The specific method is as follows:

[0066] S3-1. Count the number of photons detected by the single-photon detector in each base mask block area N 2 ×K is used as the measurement value y in the compressed sensing algorithm.

[0067] S3-2. Basis binary measurement matrix sequence Φ K As the measurement matrix Φ in compressed sensing, Φ K The number of rows M represents the number of measurements, that is, the number of masks loaded into the spatial light modulation module, and the number of columns is the total number of pixels of the base measurement matrix.

[0068] S3-3. The measurement process of compressed sensing adopts the basic expression: y = Φx, where x is the original signal to be reconstructed. The original image x of each block area is reconstructed and then reorganized in order according to the block area N×N. A reconstructed scene image X with higher resolution can be obtained.

[0069] Based on the above method, the following is provided: Figure 3-Figure 4 The embodiment shown, wherein Figure 3 The embodiment of the present invention uses an imaging resolution plate as the imaging target and reconstructs a 512×512 resolution intensity image using the proposed method. During the reconstruction process, since the base mask size is set to 128×128 and a new mask modulation sequence set is formed by 4×4 blocks, only the photon count values ​​corresponding to 4096 base masks are actually used, and a 512×512 high-resolution image can be reconstructed, and the data compression rate CR reaches a high compression rate of 1.56%.

[0070] And because of the advantage of the number of detectors in the single-photon array, the photon count values ​​at multiple positions can be recorded during the exposure time. If the exposure time is short enough, it can be regarded as that the photons arrive at the single-photon array at the same time, and the time delay τ between each detection unit is approximately 0. The statistical photon counts are subjected to photon correlation statistics, retaining g 2 (0) Taking the photon count value with a higher value as the measurement value and filtering the photon count value with a lower photon correlation intensity can effectively improve the imaging contrast. Figure 3 As shown in the left and right figures, the results show that the use of photon correlation can also effectively reduce background noise and thus improve the imaging signal-to-noise ratio and contrast.

[0071] The present invention is different from the traditional single-photon imaging scheme. It uses a block operation to splice the base binary modulation mask sequence into N×N blocks to obtain a new mask sequence for spatial light coding modulation, and uses the multi-pixel detection unit of the single-photon array detector to synchronously and parallelly measure the photon counts of each block modulation area. Finally, the photon counts and mask spatial structures in each block area are reconstructed using compressed sensing to reconstruct the block original signal, and finally the high-resolution image is synthesized in an orderly manner. Using a small block of binary modulation mask as the base mask and using block parallel modulation in conjunction with an array detector, high-resolution imaging of ≥512×512 can be achieved with only a few thousand modulation masks, which solves the technical problems of long imaging time and low imaging resolution in the traditional scheme.

[0072] Therefore, the present invention proposes the idea of ​​a base measurement matrix mask, divides the generated base measurement matrix mask into N×N parallel blocks, and splices them into a new measurement matrix mask; uses a multi-pixel single-photon detector to synchronously count the number of photons in the N×N block areas in the modulation mask, and can simultaneously obtain photon counting information in multiple areas. Combined with the known base mask spatial coding structure information, it can achieve fast, high-resolution compressed sensing single-photon imaging tasks. Compared with traditional methods, it can reconstruct single-photon imaging with higher imaging resolution and faster rate at the same modulation mask order of magnitude and the same modulation time.

[0073] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0074] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A high-resolution, fast compressed sensing single-photon array imaging system, characterized in that: include: Imaging light source, light attenuator, light beam expander, target to be measured, signal generator, spatial light modulator, single photon detection array, counting storage module and data processing module; The imaging light source is used to emit a light beam to illuminate the target scene to be imaged; the light attenuator, the light beam expander, the target to be measured and the spatial light modulator are sequentially arranged on the transmission light path of the light beam; the signal generator is respectively connected to the spatial light modulator and the single photon detection array; the single photon detection array, the counting storage module and the data processing module are sequentially connected; The optical attenuator is used to attenuate the light intensity to a single photon level to prevent damage caused by excessive light intensity; The optical beam expander is used to appropriately expand the attenuated light beam to meet the lighting requirements; The signal generator is used to provide an external clock source to synchronize data acquisition between the spatial light modulator and the single photon detection array; The spatial light modulator is used to load a binary measurement mask, and the trigger signal sent during the modulation process also establishes a synchronous measurement with the single photon detection array; The single photon detection array is used to sequentially acquire the photon count distribution corresponding to each measurement mask based on the trigger signal sent by the spatial light modulation device, and to collect the photon count distribution of multiple pixels in parallel; The counting storage module is used to perform data classification and parallel storage on the photon counting values ​​in the multi-pixel region set; The data processing module is used to use the stored photon count distribution data and the spatial distribution corresponding to the mask as data input of the compressed sensing algorithm, perform an approximate one-norm solution, and reconstruct the instantaneous image of the target to be measured.

2. The high-resolution fast compressed sensing single-photon array imaging system according to claim 1, characterized in that: The imaging light source adopts a 532nm laser.

3. A high-resolution, fast compressed sensing single-photon array imaging method, based on the system according to any one of claims 1-2, characterized in that: include: generating a binary coded measurement matrix for loading onto a spatial light modulator; Loading the binary coded measurement matrix into the spatial light modulation module to perform spatial light modulation coding; The image signal of each base mask area is reconstructed by block compression sensing, and the final target scene image is obtained by splicing; each base mask area is composed of base binary codes.

4. The high-resolution fast compressed sensing single-photon array imaging method according to claim 3, characterized in that: The generating of the binary coded measurement matrix for loading onto the spatial light modulator specifically includes: setting the size of the base measurement matrix to be m×n, and generating an initial binary coded measurement matrix Φ with a size of m×n, setting all elements of the initial binary coded measurement matrix Φ to be 0 or 1, Φ i,j ∈{0,1}, i and j are the element distributions under the binary coding measurement matrix, and a total of K measurement matrices that meet the above conditions are generated. K different measurement matrices are spliced ​​into a new binary coding measurement matrix Φ according to N×N blocks. K , {Φ K |K=1,2,…,K}, where N is the number of blocks, and the final imaging resolution is the number of blocks N multiplied by the size of the basis measurement matrix m×n.

5. The high-resolution fast compressed sensing single-photon array imaging method according to claim 4, characterized in that: The generation process of the binary coded measurement matrix is: According to the imaging resolution, the base mask matrix size is determined, the required imaging resolution is divided into N×N according to the base mask size, and a Hadamard matrix of the same order is generated according to the base mask size; The generated Hadamard matrix is ​​differentially calculated to obtain a binary measurement matrix whose values ​​are only 0 and 1. The individual rows of the Hadamard matrix are extracted to reorganize it into a square matrix with the size of the base mask. The same base mask matrix is ​​spliced ​​into N×N blocks, and the size of the mask matrix is ​​adjusted by adding zeros around it. Finally, a mask matrix that meets the resolution of the spatial light modulation module is obtained.

6. The high-resolution fast compressed sensing single-photon array imaging method according to claim 4, characterized in that: The new binary coding measurement matrix corresponds to K binary coding masks, and an all-zero mask needs to be added before the first mask and after the Kth mask as the start and stop mark masks, generating a total of K+2 mask patterns.

7. The high-resolution fast compressed sensing single-photon array imaging method according to claim 3, characterized in that: The loading of the binary coded measurement matrix into the spatial light modulation module to perform spatial light modulation coding specifically includes: The binary coded measurement matrix is ​​loaded onto the spatial light modulator. During the process of the imaging light source irradiating the target to be measured, some photons reach the spatial light modulator due to scattering, and according to the initial modulation frequency, the loaded binary coded measurement matrix is ​​used to perform spatial coding modulation on the target photons. At the same time, the spatial light modulator sends a trigger signal after the modulation cycle ends. When the single photon detection array receives the trigger signal, it performs K photon number detection on the modulated photons. Since the single photon detection array uses a multi-pixel detection method, the block binary coded measurement matrix is ​​divided into blocks according to the block area N. 2 The single-photon detection array counts the photons in blocks independently, and the final photon count is expressed as 8. The high-resolution fast compressed sensing single-photon array imaging method according to claim 7, characterized in that: The specific calculation process of the photon counting is: Set the spatial light modulator to single play, the number of mask frames of the spatial light modulator is K+2, and the play frame rate B of the spatial light modulator is set according to the exposure time of the single photon detection array; The masks corresponding to all binary coded measurement matrices are loaded onto the spatial light modulator, and the spatial light modulator performs spatial light coding modulation on the target to be measured according to 1 / B as the modulation period, and the modulated photons are received by the single photon detection array; The spatial light modulation module sends a trigger signal every 1 / B modulation cycles. The single-photon detection array receives the trigger signal, synchronously samples the modulated photons, and performs photon counting statistics in parallel and independently according to the N×N different block areas in the binary measurement matrix sequence. Finally, the photon count value of each area is calculated.

9. The high-resolution fast compressed sensing single-photon array imaging method according to claim 3, characterized in that: The method of reconstructing the image signal of each base mask area by block by compressed sensing and obtaining the final target scene image by splicing specifically includes: According to the spatial structure of the binary coded measurement matrix, each independent measurement matrix is ​​composed of N×N identical base binary coded measurement matrices, and performs parallel independent spatial light modulation tasks. The single photon detection array collects photon counts in each area in parallel. After completing a detection cycle, the photon counts of each area of ​​the block are summed up and given by Indicates that the spatial structure of the binary coding measurement matrix is ​​represented by Φ K According to the compressed sensing measurement process, the expression is given: Where X is the signal to be reconstructed, x represents the original signal to be reconstructed in each block area. Each reconstructed x is reassembled and spliced ​​according to N×N to obtain the final target scene image.

10. The high-resolution fast compressed sensing single-photon array imaging method according to claim 9, characterized in that: The reconstruction process of the target scene image is: The single-photon detection array counts the number of photons detected in each base mask block area N. 2 ×K is the measurement value y in the compressed sensing algorithm; The binary coded measurement matrix Φ K As the measurement matrix in compressed sensing, Φ K The number of rows M represents the number of measurements, which is equal to the number of masks K loaded into the spatial light modulation module, and the number of columns is the total number of pixels in the base measurement matrix; Based on the measurement value y and the binary coded measurement matrix Φ K To perform compressed sensing measurements, use the expression Reconstruct, where X is the signal to be reconstructed, x represents the original signal to be reconstructed in each block area. Each reconstructed x is reassembled and spliced ​​according to N×N to obtain the final target scene image.

Images