A method for fast imaging with large field of view and high resolution for long-range single-photon radar

Abstract

The present invention provides a long-distance single-photon radar large field of view high-resolution rapid imaging method, which can be applied to the field of laser radar technology. The method includes: constructing a long-distance single-photon large field of view scanning imaging system based on a two-dimensional dual-axis turntable and an array single-photon detector, and configuring the long-distance single-photon large field of view scanning imaging system; using the long-distance single-photon large field of view scanning imaging system to control the array single-photon detector to scan the panoramic pixel points of the target object in a raster-type continuous scanning manner by setting the motion mode of the two-dimensional dual-axis turntable, and obtaining the large-field panoramic single-photon detection data of the target object; performing real-time data compression processing based on resampling on the large-field panoramic single-photon detection data to complete the image restoration of the target object, and obtain the real image of the target object. The method provided by the present invention can adapt to different imaging scenes, and has the ability to detect large imaging fields and rapid detection capabilities.

Description

Technical Field

[0001] The present invention relates to the field of laser radar technology, and more specifically to a long-distance single-photon radar large-field-of-view high-resolution rapid imaging method. Background Art

[0002] LiDAR is one of the most widely used precise three-dimensional imaging technologies. Its main principle is to emit laser pulses to the target area and receive the echo, and measure the flight time of the photons to obtain the distance between the target and the emission point. LiDAR three-dimensional imaging technology is widely used in unmanned driving, urban mapping and modeling, target recognition and other fields. The increasingly wide application demand also promotes the further improvement of single-photon radar in terms of range, imaging resolution and imaging field of view.

[0003] Among the existing technical solutions, there are many technical problems in the large field of view, high resolution and fast imaging methods of long-distance single-photon radar: for single-photon lidar, it is difficult to achieve large field of view imaging while maintaining high lateral resolution; in order to achieve both large field of view and high resolution, array detectors are needed, but the currently available SPAD (Single Photon Avalanche Diode) array detectors are small in size and cannot meet the requirements of large field of view imaging and high resolution; and the use of multiple array detectors for splicing will lead to increased power consumption and excessive size of the imaging system; and the technical solution of using a pointing mechanism in conjunction with an array detector also has insufficient imaging field expansion capabilities and cannot effectively achieve large field of view imaging in the entire airspace; in addition, to achieve efficient large field of view imaging, it is also necessary to consider the problem of large data processing volume caused by high resolution. Summary of the invention

[0004] In view of the above problems, the present invention provides a long-range single-photon radar large field of view high resolution fast imaging method, which is used to solve at least one of the problems in the prior art.

[0005] According to a first aspect of the present invention, a method for fast imaging with large field of view and high resolution of a long-range single-photon radar is provided, comprising:

[0006] A long-distance single-photon large-field-of-view scanning imaging system is constructed based on a two-dimensional dual-axis turntable and an array single-photon detector, and the long-distance single-photon large-field-of-view scanning imaging system is configured;

[0007] The long-distance single-photon large-field-of-view scanning imaging system is used to control the array single-photon detector to scan the panoramic pixel points of the target object in a raster-type continuous scanning manner by setting the motion mode of a two-dimensional dual-axis turntable, so as to obtain the large-field-of-view panoramic single-photon detection data of the target object;

[0008] The large-field panoramic single-photon detection data is subjected to real-time data compression processing based on resampling to complete the image restoration of the target object and obtain the real image of the target object.

[0009] According to an embodiment of the present invention, the long-distance single-photon large-field scanning imaging system based on a two-dimensional dual-axis turntable and an array single-photon detector comprises:

[0010] The long-distance single-photon large-field scanning imaging system is constructed by using a two-dimensional dual-axis turntable, the array single-photon detector, a laser, a transmitting antenna, a receiving antenna and a combined spectral filter.

[0011] According to an embodiment of the present invention, the configuration of the long-distance single-photon large-field-of-view scanning imaging system includes:

[0012] A laser with a preset atmospheric transmittance is selected as a light source at the transmitting end of a long-distance single-photon large-field-of-view scanning imaging system;

[0013] Using a transmitting antenna to adjust the divergence angle and direction of an outgoing light beam from a laser;

[0014] A single-photon array detector with a preset working band is used as an array single-photon detector of a long-distance single-photon large-field scanning imaging system;

[0015] The solar background noise is suppressed by combining spectral filters, and the signal photons diffusely reflected by the target object are collected by the receiving antenna;

[0016] Based on the horizontal structure design, a two-dimensional dual-axis turntable is controlled by a stepper motor, and the two-dimensional dual-axis turntable is used to control the scanning of the long-distance single-photon large-field-of-view scanning imaging system along the azimuth axis and the pitch axis, wherein the azimuth axis and the pitch axis pass through the optical axis of the long-distance single-photon large-field-of-view scanning imaging system.

[0017] According to an embodiment of the present invention, the long-distance single-photon large-field-of-view scanning imaging system uses a two-dimensional dual-axis turntable to control the array single-photon detector to scan the panoramic pixel points of the target object in a raster-type continuous scanning manner, and obtains the large-field-of-view panoramic single-photon detection data of the target object, including:

[0018] Set the motion mode of the two-dimensional dual-axis turntable to eliminate image distortion during scanning, and define the same area of ​​the target object in the imaging scene as a panoramic pixel point;

[0019] The motion pattern of the two-dimensional dual-axis turntable controls the array single-photon detector to perform raster-type continuous scanning of all panoramic pixel points of the target object;

[0020] The panoramic scanning data generated by all panoramic pixel points of the target object in the raster-type continuous scanning process are processed to obtain large-field panoramic single-photon detection data.

[0021] According to an embodiment of the present invention, the motion modes of the two-dimensional dual-axis turntable include:

[0022] The two-dimensional dual-axis turntable is set to perform raster scanning so as to switch to the initial position of the next line to continue scanning when the line is scanned to the end;

[0023] The scanning start and end points of the two-dimensional dual-axis turntable are set outside the area to be imaged, and the data obtained outside the area to be imaged are discarded;

[0024] A two-dimensional dual-axis turntable is used to set a scanning overlap area between the upper and lower scanning areas to facilitate image stitching in the data processing stage.

[0025] According to an embodiment of the present invention, the panoramic scanning data generated by all panoramic pixel points of the target object in the raster-type continuous scanning process is processed to obtain large-field panoramic single-photon detection data, including:

[0026] For the same row of panoramic scanning data during the raster-type continuous scanning process, the echo signals generated by the detection of the panoramic pixel points of the target object by different array detection pixels of the array single-photon detector are collected, and histogram statistics are performed based on the flight time of the photons to obtain a single row of large-field panoramic single-photon detection data;

[0027] For multiple lines of panoramic scanning data in the raster-type continuous scanning process, based on the normalized cross-correlation method, the overlapping areas between multiple lines are used to stitch the multiple lines of panoramic scanning data to obtain multiple lines of large-field-of-view panoramic single-photon detection data.

[0028] According to an embodiment of the present invention, for the multiple lines of panoramic scanning data in the raster-type continuous scanning process, based on the normalized cross-correlation method, the multiple lines of panoramic scanning data are spliced ​​using the overlapping areas between the multiple lines to obtain multiple lines of large-field panoramic single-photon detection data, including:

[0029] For the panoramic scanning data between the upper and lower rows, the single photon echo signal of the upper row is used as the reference result, and the single photon echo signal of the lower row is used as the floating result;

[0030] The normalized cross-correlation method is used to calculate the correlation between the upper and lower rows of panoramic scanning data, and the panoramic scanning data with corresponding positions are merged based on the correlation to obtain multiple rows of large-field panoramic single-photon detection data.

[0031] According to an embodiment of the present invention, the above-mentioned real-time data compression processing based on resampling of the large-field panoramic single-photon detection data to complete the image restoration of the target object to obtain the real image of the target object includes:

[0032] Perform preliminary noise filtering on the large-field panoramic single-photon detection data in the spatial dimension and the temporal dimension to obtain the large-field panoramic single-photon detection data after noise filtering;

[0033] By setting different resampling periods and repeatedly performing resampling operations and convex optimization reconstruction operations on the large-field panoramic single-photon detection data after noise filtering using different resampling periods, the target image of the target object at different resampling periods is obtained;

[0034] The common multiples of the target images of the target object at different resampling periods are solved to obtain the real image of the target object.

[0035] According to an embodiment of the present invention, the above-mentioned preliminary noise filtering processing is performed on the large-field panoramic single-photon detection data in the spatial dimension and the temporal dimension to obtain the large-field panoramic single-photon detection data after noise filtering, which includes:

[0036] Perform data density statistics on the large-field panoramic single-photon detection data in the spatial dimension to obtain the spatial density distribution function of the large-field panoramic single-photon detection data;

[0037] Set a spatial density threshold, and set the data positions corresponding to the spatial density distribution function being lower than the spatial density threshold to zero;

[0038] Perform pixel merging on the time dimension of the large field of view panoramic single photon detection data to obtain the time density distribution function;

[0039] A time density threshold is set, a data position corresponding to a time density distribution function being lower than the time density threshold is determined, and a zeroing operation is performed on the large-field panoramic single-photon detection data corresponding to the determined data position.

[0040] According to an embodiment of the present invention, the above-mentioned resampling operation and convex optimization reconstruction operation are repeatedly performed on the large field of view panoramic single-photon detection data after noise filtering by setting different resampling periods and using different resampling periods to obtain the target image of the target object at different resampling periods, including:

[0041] Set the resampling period of the current stage, and use the resampling period of the current stage to resample the large field of view panoramic single photon detection data after noise filtering;

[0042] The resampled large-field panoramic single-photon detection data is reconstructed by convex optimization, and the convex optimization reconstruction process is constrained by introducing a penalty term to obtain the target image of the target object at the current stage;

[0043] The resampling period setting operation, the resampling operation and the convex optimization reconstruction operation are repeated to obtain the target image of the target object at different resampling periods.

[0044] Compared with the laser radar imaging method in the prior art, the above-mentioned long-distance single-photon radar large field of view high-resolution rapid imaging method provided by the present invention adopts the long-distance single-photon large field of view scanning imaging system newly designed and configured by the present invention, so that the high-precision two-dimensional dual-axis turntable and the array single-photon detector can cooperate with each other, so that the method provided by the present invention can adapt to different imaging scenes and have large imaging field of view detection capability and rapid detection capability; at the same time, the grating continuous scanning method provided by the present invention has low requirements on the pointing accuracy of related hardware equipment in the process of uniformly scanning and detecting the same row of data, and the data between different rows retains a certain data overlap area, improves the data splicing quality between rows, and has high-quality detection capability; in addition, the present invention provides a solution for accelerated processing of big data, adopts a convex optimization reconstruction algorithm, and uses a penalty term to control the image reconstruction process, has high-quality image reconstruction capability, adopts a data compression processing method, reduces the data processing amount, and takes into account the image processing speed while retaining the high-quality image reconstruction capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The above contents and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0046] Figure 1 is a flow chart of a method for fast imaging with high resolution and large field of view by a long-range single-photon radar according to an embodiment of the present invention;

[0047] Figure 2 is a schematic structural diagram of a long-distance single-photon large-field-of-view scanning imaging system according to an embodiment of the present invention;

[0048] Figure 3 is a schematic diagram of a method for collecting large field of view image data according to an embodiment of the present invention;

[0049] Figure 4 The block diagram of an electronic device suitable for implementing a method for fast imaging with a large field of view and high resolution by a long-range single-photon radar according to an embodiment of the present invention is schematically shown. DETAILED DESCRIPTION

[0050] Below, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of concepts of the present invention.

[0051] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0052] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0053] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0054] For long-distance imaging, single-photon lidar systems face the challenge that the echo light signal and signal-to-background ratio (SBR) decrease rapidly as the imaging distance R increases. In terms of hardware, researchers have designed an optical system with high efficiency in echo signal photon reception and background noise suppression by optimizing the optical system. In terms of software, computational imaging algorithms have also made significant progress in efficiently processing single-photon data. The relevant algorithms show good performance under weak echo signals and high background noise, and can reconstruct high-quality depth maps and reflectivity maps at the detection level of one photon per pixel (PPP). Some technical researchers have successfully demonstrated long-distance three-dimensional imaging of more than 200 kilometers by improving the system efficiency of single-photon lidar and the image reconstruction capability of single-photon algorithms. Single-photon lidar has made significant breakthroughs in terms of range. However, as the range increases, the contradiction between resolution and large imaging field of view becomes more serious. For single-photon lidar, it is already a severe challenge to achieve large field of view imaging while maintaining high lateral resolution.

[0055] Using array detectors is a solution that can achieve both large field of view and high resolution. However, due to the limitations of semiconductor manufacturing processes, currently available SPAD arrays still have small array sizes. Therefore, directly using these SPAD arrays still cannot meet the requirements of large imaging field of view and high resolution at the same time. Using multiple array detectors for stitching is undoubtedly a more direct solution, but this also increases system power consumption and system size. In contrast, using a pointing mechanism in conjunction with array detection is a more cost-effective solution. Some technical researchers have expanded the imaging area and increased the total number of pixels by mounting single-photon array detectors on a two-axis electric translation stage and using multiple image stitching. Other technical researchers have expanded the imaging field of view by combining single-photon array detectors with Risley prism scanning mechanisms. However, the image stitching accuracy of these methods mainly depends on the pointing accuracy of the turntable, and the accuracy requirements of the system steering mechanism are high. At the same time, these methods are limited by the angle of the pointing mechanism, and have limited ability to expand the imaging field of view, and cannot effectively achieve large field of view imaging in the entire airspace. At the same time, to achieve efficient large field of view imaging, it is also necessary to consider the problem of large data processing volume caused by high resolution. Therefore, technological breakthroughs are still urgently needed to achieve long-range single-photon radar, large field of view, high resolution and fast imaging.

[0056] The present invention aims to solve the contradiction between the large imaging field of view and the imaging resolution faced by the existing single-photon laser radar in the long-distance imaging scene, and proposes a long-distance single-photon large-field scanning imaging system using a high-precision two-dimensional turntable and an array single-photon detector, and also proposes a raster-type continuous scanning large-field image data acquisition method and a data processing method using resampling for data compression. The system and method proposed by the present invention can achieve long-distance large-field high-resolution three-dimensional imaging, and has real-time data processing efficiency.

[0057] Figure 1 The present invention is a flowchart of a method for long-distance single-photon radar with large field of view and high resolution and fast imaging according to an embodiment of the present invention.

[0058] like Figure 1 As shown, the above-mentioned long-distance single-photon radar large field of view high resolution rapid imaging method includes operations S110 to S130.

[0059] In operation S110, a long-distance single-photon large-field-of-view scanning imaging system is constructed based on a two-dimensional dual-axis turntable and an array single-photon detector, and the long-distance single-photon large-field-of-view scanning imaging system is configured.

[0060] The above-mentioned two-dimensional dual-axis turntable generally uses a high-precision two-dimensional dual-axis turntable with an azimuth axis and a pitch axis, so that the array single-photon detector can be controlled with high precision.

[0061] The above-mentioned two-dimensional dual-axis turntable and array single-photon detector are the core devices of the long-distance single-photon large-field-of-view scanning imaging system designed by the present invention. Before detecting the target object, each device in the long-distance single-photon large-field-of-view scanning imaging system needs to be configured.

[0062] In operation S120, a long-distance single-photon large-field-of-view scanning imaging system is used to control an array of single-photon detectors to scan panoramic pixel points of a target object in a raster-like continuous scanning manner by setting a motion mode of a two-dimensional dual-axis turntable to obtain large-field-of-view panoramic single-photon detection data of the target object.

[0063] In order to achieve large field of view image data acquisition and avoid the influence of image distortion introduced by the turntable control accuracy, it is necessary to set the motion mode of the two-dimensional dual-axis turntable.

[0064] In operation S130, a real-time data compression process based on resampling is performed on the large-field panoramic single-photon detection data to restore the image of the target object and obtain a real image of the target object.

[0065] Since the amount of detection data generated is large, a new data processing method is needed to speed up the acquisition of real images of target objects and achieve rapid detection capabilities.

[0066] Compared with the laser radar imaging method in the prior art, the above-mentioned long-distance single-photon radar large field of view high-resolution rapid imaging method provided by the present invention adopts the long-distance single-photon large field of view scanning imaging system newly designed and configured by the present invention, so that the high-precision two-dimensional dual-axis turntable and the array single-photon detector can cooperate with each other, so that the method provided by the present invention can adapt to different imaging scenes and have large imaging field of view detection capability and rapid detection capability; at the same time, the grating continuous scanning method provided by the present invention has low requirements on the pointing accuracy of related hardware equipment in the process of uniformly scanning and detecting the same row of data, and the data between different rows retains a certain data overlap area, improves the data splicing quality between rows, and has high-quality detection capability; in addition, the present invention provides a solution for accelerated processing of big data, adopts a convex optimization reconstruction algorithm, and uses a penalty term to control the image reconstruction process, has high-quality image reconstruction capability, adopts a data compression processing method, reduces the data processing amount, and takes into account the image processing speed while retaining the high-quality image reconstruction capability.

[0067] According to an embodiment of the present invention, the above-mentioned long-distance single-photon large-field-of-view scanning imaging system based on a two-dimensional two-axis turntable and an array single-photon detector includes: using the two-dimensional two-axis turntable, the array single-photon detector, a laser, a transmitting antenna, a receiving antenna and a combined spectral filter to construct the long-distance single-photon large-field-of-view scanning imaging system.

[0068] The above embodiments illustrate the main components of a long-distance single-photon large-field-of-view scanning imaging system. Those skilled in the art may expand the above components based on the embodiments disclosed in the present invention, for example, by using a two-dimensional dual-axis turntable, an array single-photon detector, a laser (for example, a pulsed fiber laser), a transmitting antenna (the transmitting antenna, optionally, includes an optical fiber, a collimator, a two-dimensional adjustment frame, a signal generator), a combined spectral filter (for example, a spectral filter with a long-pass filter and a band-pass filter), and a receiving antenna (the receiving antenna, optionally, includes a telescope with a preset aperture (for example, a Cassegrain telescope), an optical lens) to construct a long-distance single-photon large-field-of-view scanning imaging system.

[0069] According to an embodiment of the present invention, the above-mentioned configuration of the long-distance single-photon large-field-of-view scanning imaging system includes: selecting a laser with a preset atmospheric transmittance as a light source at the transmitting end of the long-distance single-photon large-field-of-view scanning imaging system; using a transmitting antenna to adjust the divergence angle and direction of the outgoing light beam from the laser; using a single-photon array detector with a preset working band as an array single-photon detector of the long-distance single-photon large-field-of-view scanning imaging system; suppressing the solar background noise through a combined spectral filter, and using a receiving antenna to collect signal photons diffusely reflected back by the target object; based on a horizontal structure design and using a stepper motor to control a two-dimensional dual-axis turntable, and using the two-dimensional dual-axis turntable to scan and control the long-distance single-photon large-field-of-view scanning imaging system along the azimuth axis and the pitch axis, wherein the azimuth axis and the pitch axis pass through the optical axis of the long-distance single-photon large-field-of-view scanning imaging system.

[0070] In the above embodiment, the optical fiber in the transmitting antenna is used to connect the laser and the collimator in the transmitting antenna; at the same time, the collimator is fixed on a two-dimensional adjustment frame in the transmitting antenna to adjust the coaxiality of the outgoing light beam; at the same time, an optical lens in the receiving antenna is arranged on the rear end optical path of a telescope with a preset aperture in the receiving antenna, and the optical lens is used to adjust the detection field of view of the receiving end of the long-distance single-photon large-field-of-view scanning imaging system.

[0071] Figure 2 Schematic diagram of the structure of a long-distance single-photon large-field-of-view scanning imaging system according to an embodiment of the present invention.

[0072] The following is a specific embodiment and combined with the attached Figure 2The structure of the long-distance single-photon large-field-of-view scanning imaging system and the configuration process in the long-distance single-photon large-field-of-view scanning imaging system provided by the present invention are further described in detail.

[0073] Long-distance single-photon large-field scanning imaging system Figure 2 As shown. The long-distance single-photon large-field-of-view scanning imaging system mainly consists of a single-photon radar (i.e., an array single-photon detector, the same below) and a high-precision two-dimensional turntable (i.e., a two-dimensional dual-axis turntable, the same below). The single-photon lidar adopts a separate optical structure design for transmission and reception, which can effectively reduce the noise impact caused by local optical reflections and atmospheric backscattering. The transmitting end of the long-distance single-photon large-field-of-view scanning imaging system uses a pulsed fiber laser, which has the advantages of eye safety and good atmospheric transmittance. The other end of the optical fiber is fixed to a collimator to adjust the divergence angle of the outgoing light beam and provide a field-of-view matching floodlight for the detection end. The collimator is fixed on a two-dimensional adjustment frame to facilitate the adjustment of the coaxiality of the outgoing light path. The receiving end of the system uses a single-photon array detector (for example: 64 64 InGaAs / InP single-photon array detector), its preset working band can cover 950-1650nm. In order to meet the imaging scene requirements of all day, the long-distance single-photon large-field-of-view scanning imaging system also uses long-pass and band-pass filters for combined filtering, which can effectively suppress the influence of solar background noise. The receiving end of the long-distance single-photon large-field-of-view scanning imaging system also includes a commercial 280mm-diameter telescope (for example: Cassegrain telescope) to collect signal photons diffusely reflected from the target. The rear-end optical path is also equipped with an optical lens to adjust the detection field of view of the receiving end to meet the specific imaging scene requirements.

[0074] The high-precision two-dimensional turntable is custom-designed with a high-precision stepper motor to assist the single-photon radar in achieving large-field-of-view scanning detection. The high-precision two-dimensional turntable adopts a horizontal structure design to realize scanning control of the single-photon radar along the azimuth axis and the pitch axis respectively. At the same time, in order to ensure the scanning imaging accuracy of the single-photon radar, the azimuth axis and the pitch axis of the turntable must pass through the optical axis of the long-distance single-photon large-field-of-view scanning imaging system during the structural design process. In addition, the design must also fully consider the center of mass position of the long-distance single-photon large-field-of-view scanning imaging system to avoid excessive torque and maintain stability during movement. The use of a high-precision two-dimensional turntable can realize the pointing position control and speed control of the single-photon radar according to needs.

[0075] According to an embodiment of the present invention, the above-mentioned long-distance single-photon large-field-of-view scanning imaging system controls the array single-photon detector to scan the panoramic pixel points of the target object in a raster-like continuous scanning manner by setting the motion mode of the two-dimensional two-axis turntable to obtain the large-field-of-view panoramic single-photon detection data of the target object, including: setting the motion mode of the two-dimensional two-axis turntable to eliminate image distortion during the scanning process, and defining the same area of ​​the target object in the imaging scene as a panoramic pixel point; controlling the array single-photon detector to perform raster-like continuous scanning on all panoramic pixel points of the target object based on the motion mode of the two-dimensional two-axis turntable; processing the panoramic scanning data generated by all panoramic pixel points of the target object in the raster-like continuous scanning process to obtain large-field-of-view panoramic single-photon detection data.

[0076] According to an embodiment of the present invention, the movement mode of the above-mentioned two-dimensional dual-axis turntable includes: setting the two-dimensional dual-axis turntable for raster scanning to switch to the initial position of the next row to continue scanning when scanning to the end of the row; setting the scanning start and end points of the two-dimensional dual-axis turntable outside the area to be imaged, and discarding the data obtained outside the area to be imaged; using the two-dimensional dual-axis turntable to set a scanning overlap area between the upper and lower scanning areas to facilitate image stitching in the data processing stage.

[0077] Figure 3 Schematic diagram of a method for acquiring large-field-of-view image data according to an embodiment of the present invention.

[0078] In order to achieve large field of view image data acquisition and avoid image distortion caused by turntable control accuracy, the following restrictions need to be imposed on the turntable movement:

[0079] (1) The two-dimensional dual-axis turntable scans in a raster manner, for example, scanning horizontally from left to right at a uniform speed. When the scan reaches the end of a line, it switches to the initial position of the next line and continues scanning, such as Figure 3 As shown by the dashed line in the middle; (2) In order to avoid the image distortion problem caused by the uneven speed process at the start and end stages of the turntable scanning, the start and end points of the turntable scanning are set outside the area to be imaged. In the subsequent data processing, this part of the data is discarded by default; (3) There is a certain scanning overlap area between the next two scanning areas (such as Figure 3 for subsequent image stitching.

[0080] According to an embodiment of the present invention, the panoramic scanning data generated by all panoramic pixels of the target object in the grating continuous scanning process are processed to obtain large-field-of-view panoramic single-photon detection data, including: for the same row of panoramic scanning data in the grating continuous scanning process, the echo signals generated by the different array detection pixels of the array single-photon detector detecting the panoramic pixels of the target object are collected, and histogram statistics are performed based on the flight time of the photons to obtain a single row of large-field-of-view panoramic single-photon detection data; for multiple rows of panoramic scanning data in the grating continuous scanning process, based on the normalized cross-correlation method, the multiple rows of panoramic scanning data are spliced ​​using the overlapping areas between the multiple rows to obtain multiple rows of large-field-of-view panoramic single-photon detection data.

[0081] According to an embodiment of the present invention, based on the normalized cross-correlation method, the multiple lines of panoramic scanning data in the grating continuous scanning process are spliced ​​using the overlapping areas between the multiple lines to obtain multiple lines of large-field-of-view panoramic single-photon detection data, including: for the panoramic scanning data between the upper and lower lines, the single-photon echo signal of the upper line is used as a reference result, and the single-photon echo signal of the lower line is used as a floating result; the normalized cross-correlation method is used to calculate the correlation between the upper and lower lines of panoramic scanning data, and the panoramic scanning data with corresponding positions are merged based on the correlation to obtain multiple lines of large-field-of-view panoramic single-photon detection data.

[0082] The above-mentioned large-field-of-view image data acquisition process provided by the present invention is further described in detail below through specific embodiments.

[0083] During the scanning imaging process, different pixels of the array camera will sequentially scan the target signals in the same area of ​​the imaging scene. Here, the same area in the imaging scene is defined as a panoramic pixel point. Therefore, before data processing, it is necessary to collect the echo signals detected by different array detection pixels from the same panoramic pixel. Assume that the scanning speed of the turntable is set along Direction in angular velocity Uniform motion, the field of view corresponding to a single pixel of the array detector is , the imaging frame rate of the detector is , then the pixel in the array detector No. Frame detection data, corresponding to panoramic pixels The corresponding relationship of the echo signal is shown in formulas (1) and (2):

[0084] (1),

[0085] (2),

[0086] in, are respectively the panoramic pixel position coordinates, for example, the horizontal coordinate and the vertical coordinate of the panoramic pixel. Those skilled in the art may calculate the horizontal coordinate and the vertical coordinate according to actual needs. The meaning represented is expanded to correspond to the same panoramic pixel in all frame data detected by all pixels in the detector The echo signal is collected and the flight time of the photon is tracked By performing histogram statistics, we get the panoramic pixels The detection data By performing the above processing on all panoramic pixels in the same row of data, a single row of panoramic scanning data is obtained.

[0087] For the panoramic scan data between the upper and lower rows, the normalized cross-correlation method is used to obtain the overlap area. The panoramic scan data of the upper and lower rows are spliced. As a reference result, the single photon echo signal in the next row As a floating result, using the normalized cross-correlation method, the correlation between the two can be expressed by formula (3):

[0088] (3).

[0089] in, Indicates the offset of the next row relative to the previous row, by finding the position with the highest correlation , and merge the detection data at the corresponding positions to finally obtain panoramic single-photon detection data with a large field of view, as shown in formula (4):

[0090] (4).

[0091] According to an embodiment of the present invention, the above-mentioned real-time data compression processing based on resampling of the large-field panoramic single-photon detection data to complete the image restoration of the target object to obtain the real image of the target object includes: performing preliminary noise filtering processing on the large-field panoramic single-photon detection data in the spatial dimension and the temporal dimension to obtain the noise-filtered large-field panoramic single-photon detection data; setting different resampling periods and using different resampling periods to repeatedly perform resampling operations and convex optimization reconstruction operations on the noise-filtered large-field panoramic single-photon detection data to obtain the target images of the target object at different resampling periods; solving the common multiples of the target images of the target object at different resampling periods to obtain the real image of the target object.

[0092] According to an embodiment of the present invention, the above-mentioned preliminary noise filtering processing on the large field of view panoramic single-photon detection data in the spatial dimension and the temporal dimension to obtain the noise-filtered large field of view panoramic single-photon detection data includes: performing data density statistics on the large field of view panoramic single-photon detection data in the spatial dimension to obtain the spatial density distribution function of the large field of view panoramic single-photon detection data; setting a spatial density threshold, and setting the data positions corresponding to the spatial density distribution function being lower than the spatial density threshold to zero; performing pixel merging on the large field of view panoramic single-photon detection data in the temporal dimension to obtain the temporal density distribution function; setting the temporal density threshold, determining the data positions corresponding to the temporal density distribution function being lower than the temporal density threshold, and setting the large field of view panoramic single-photon detection data corresponding to the determined data positions to zero.

[0093] According to an embodiment of the present invention, the above-mentioned resampling operation and convex optimization reconstruction operation are repeatedly performed on the large field of view panoramic single-photon detection data after noise filtering by setting different resampling periods and using different resampling periods to obtain the target image of the target object at different resampling periods, including: setting the resampling period of the current stage, and resampling the large field of view panoramic single-photon detection data after noise filtering by using the resampling period of the current stage; performing convex optimization reconstruction on the resampled large field of view panoramic single-photon detection data, and constraining the convex optimization reconstruction process by introducing a penalty term to obtain the target image of the target object at the current stage; repeating the resampling period setting operation, the resampling operation and the convex optimization reconstruction operation to obtain the target image of the target object at different resampling periods.

[0094] The above-mentioned real-time data compression processing process based on resampling provided by the present invention is further described in detail below through specific embodiments.

[0095] Through the above-mentioned panoramic image data acquisition method, a large field of view detection data with a high number of pixels can be obtained. However, to reconstruct and restore these detection data to obtain target position information and reflectivity information, it often brings huge challenges to the data processing system. Especially in long-distance imaging scenes, the detection signal often faces problems such as low signal-to-noise ratio and weak echo signal. Traditional methods such as cross-correlation method and peak finding method often cannot reconstruct and obtain better target results. For processing single-photon detection data with low signal-to-noise ratio and weak echo signal, the existing technology often needs to use some target prior conditions to constrain the data reconstruction process, such as using TV norm, L1 norm, etc., and use convex optimization algorithm for likelihood estimation. However, directly using such algorithms for big data processing often requires a huge amount of time. In the present invention, a data processing method using resampling for data compression is proposed. By compressing the data, the image reconstruction performance of the original algorithm is retained while reducing the data processing amount, and real-time processing of such large pixel data can be realized.

[0096] In order to solve the technical problems faced by the prior art in the process of processing massive large-pixel data, the present invention uses a resampling method to perform data compression processing on the acquired panoramic scanning data.

[0097] First, the raw data needs to be initially filtered for noise. Considering that in actual imaging scenarios, the imaging targets are not continuously distributed in space, but rather have a certain degree of sparsity, the echo signals of the single-photon radar have a certain degree of clustering in the spatial and temporal dimensions. On the one hand, considering the clustering in the spatial dimension, the panoramic single-photon detection data By performing data density statistics, the spatial density distribution function of the panoramic single-photon detection data is obtained, as shown in formula (5):

[0098] (5),

[0099] The density statistics function is a three-dimensional function determined according to the actual imaging scene. By setting a spatial density threshold The data positions corresponding to the spatial density distribution function being lower than the density threshold are set to zero. The spatial density threshold here needs to be set according to the specific experimental scene. Generally, for scenes with high background noise, the corresponding spatial density threshold needs to be set relatively high.

[0100] On the other hand, considering the clustering of echo signals in the time dimension, all pixels are merged to obtain the time density distribution function, as shown in formula (6):

[0101] (6).

[0102] By setting a time density threshold And set the panoramic single photon detection data corresponding to the data position where the time density distribution function is lower than the time density threshold to zero. The time density threshold here needs to be set according to the specific experimental scene. Generally, for scenes with high background noise, the corresponding time density threshold needs to be set higher. Through this operation, the noise filtering of the original data is realized. The data after noise filtering is recorded as .

[0103] Second, set the resampling period , the original data is resampled. In order to reduce the amount of data processing, a shorter sampling period will be used here , generally requires a resampling period smaller than the laser pulse period , as shown in formula (7):

[0104] (7),

[0105] in, represents the flight time of another photon; express function, Represents the remainder function; then, the resampled data is reconstructed by convex optimization. Since the previous step has used a shorter sampling period to compress the original data in the time dimension, the speed of this convex optimization process will be improved due to the reduction of data volume. Considering that the actual imaging target is generally continuous, a penalty term is introduced here to constrain the convex optimization process, as shown in formulas (8) and (9):

[0106] (8),

[0107] (9),

[0108] in, represents the target distance image, represents the target intensity image, is the weight coefficient of the penalty term, is the likelihood function, For penalty items.

[0109] Finally, multiple resampling cycles are used to restore the target image. Since a shorter sampling cycle is used to resample the original data, the distance ambiguity problem will inevitably be introduced due to the shorter sampling cycle while compressing the data volume. Therefore, the present invention will use multiple resampling cycles to solve the distance ambiguity problem. Here, by using multiple different resampling cycles Resample and repeat the above second step in sequence to restore the distribution and obtain the target distance image under different sampling periods Finally, by solving the common multiples, Indicates The number of compressed cycles is finally used to obtain the real image of the target, as shown in formula (10):

[0110] (10).

[0111] The above-mentioned method and the long-distance single-photon large field of view scanning imaging system provided by the present invention have the following advantages over the previous laser imaging radar: (1) The long-distance single-photon large field of view scanning imaging system proposed by the present invention adopts a high-precision two-dimensional turntable with an array single-light detector, which can adapt to different imaging scenes and has a large imaging field of view detection capability and a fast detection capability. (2) In the grating scanning method proposed by the present invention, the data of the same row adopts a uniform scanning detection method, which has lower requirements on the pointing accuracy of the device and has a fast detection capability. (3) In the grating scanning method proposed by the present invention, the data between different rows retains a certain data overlap area, improves the data splicing quality between rows, and has a high-quality detection capability. (4) The big data acceleration processing method proposed by the present invention adopts a convex optimization reconstruction algorithm and uses a penalty term to control the image reconstruction process, and has a high-quality image reconstruction capability. (5) The big data acceleration processing method proposed by the present invention adopts a data compression processing method to reduce the data processing amount, while retaining the high-quality image reconstruction capability, taking into account the image processing speed.

[0112] The effectiveness and advantages of the method provided by the present invention are illustrated by specific experiments below.

[0113] The specific experiment of the present invention is illustrated by a target with an imaging field width of about 1.6° and a height of about 2.1°d. In order to obtain better rapid scanning imaging results, the present invention selects an optical lens to adjust the system's single-pixel field of view to 7.2". Correspondingly, the system's laser divergence angle is set to 0.13°, which just covers the field of view of the single-photon array detector. The system's laser output power is set to 1W, and the laser emission repetition rate is set to 25kHz. In order to achieve detection of the entire target field of view, the turntable is set to 0.08° / s in the horizontal direction, that is, the corresponding single-photon imaging system scans approximately 39 pixels per second. In the vertical direction, in order to ensure the accuracy of image stitching between the upper and lower lines, the present invention sets a 0.01° field of view overlap area. The final scanning acquisition time for the entire image is about 7.2 minutes. By using an algorithm to perform pixel segmentation, point cloud stitching, and convex optimization processing on the collected data, a single-photon image reconstruction result with a large field of view is finally obtained, and its imaging resolution is 1052 803.

[0114] Figure 4 The block diagram of an electronic device suitable for implementing a method for fast imaging with a large field of view and high resolution by a long-range single-photon radar according to an embodiment of the present invention is schematically shown.

[0115] like Figure 4As shown, the electronic device 400 according to an embodiment of the present invention includes a processor 401, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 402 or a program loaded from a storage part 408 to a random access memory (RAM) 403. The processor 401 may include, for example, a general-purpose microprocessor (such as a CPU), an instruction set processor and / or a related chipset and / or a special-purpose microprocessor (for example, an application-specific integrated circuit (ASIC)), etc. The processor 401 may also include an onboard memory for caching purposes. The processor 401 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present invention.

[0116] In RAM 403, various programs and data required for the operation of electronic device 400 are stored. Processor 401, ROM 402 and RAM 403 are connected to each other via bus 404. Processor 401 performs various operations of the method flow according to the embodiment of the present invention by executing the programs in ROM 402 and / or RAM 403. It should be noted that the program can also be stored in one or more memories other than ROM 402 and RAM 403. Processor 401 can also perform various operations of the method flow according to the embodiment of the present invention by executing the programs stored in the one or more memories.

[0117] According to an embodiment of the present invention, the electronic device 400 may further include an input / output (I / O) interface 405, which is also connected to the bus 404. The electronic device 400 may further include one or more of the following components connected to the input / output (I / O) interface 405: an input portion 406 including a keyboard, a mouse, etc.; an output portion 407 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage portion 408 including a hard disk, etc.; and a communication portion 409 including a network interface card such as a LAN card, a modem, etc. The communication portion 409 performs communication processing via a network such as the Internet. A drive 410 is also connected to the input / output (I / O) interface 405 as needed. A removable medium 411, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 410 as needed, so that a computer program read therefrom is installed into the storage portion 408 as needed.

[0118] The present invention also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiment; or may exist independently without being assembled into the device / apparatus / system. The above computer-readable storage medium carries one or more programs, and when the above one or more programs are executed, the method according to the embodiment of the present invention is implemented.

[0119] According to an embodiment of the present invention, the computer-readable storage medium may be a non-volatile computer-readable storage medium, for example, it may include but is not limited to: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present invention, the computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, an apparatus or a device. For example, according to an embodiment of the present invention, the computer-readable storage medium may include the ROM 402 and / or RAM 403 described above and / or one or more memories other than ROM 402 and RAM 403.

[0120] The embodiment of the present invention also includes a computer program product, which includes a computer program, and the computer program contains program code for executing the method shown in the flowchart. When the computer program product is run in a computer system, the program code is used to enable the computer system to implement the long-range single-photon radar large field of view high-resolution fast imaging method provided by the embodiment of the present invention.

[0121] The computer program executes the above functions defined in the system / device of the embodiment of the present invention when the processor 401 executes the computer program. According to the embodiment of the present invention, the system, device, module, unit, etc. described above can be implemented by a computer program module.

[0122] In one embodiment, the computer program may rely on tangible storage media such as optical storage devices, magnetic storage devices, etc. In another embodiment, the computer program may also be transmitted and distributed in the form of signals on a network medium, and downloaded and installed through the communication part 409, and / or installed from the removable medium 411. The program code contained in the computer program may be transmitted using any appropriate network medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0123] In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 409, and / or installed from the removable medium 411. When the computer program is executed by the processor 401, the above functions defined in the system of the embodiment of the present invention are performed. According to the embodiment of the present invention, the system, device, means, module, unit, etc. described above can be implemented by a computer program module.

[0124] According to an embodiment of the present invention, the program code for executing the computer program provided by the embodiment of the present invention can be written in any combination of one or more programming languages. Specifically, these computing programs can be implemented using high-level process and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, Java, C++, python, "C" language or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, partially on the remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., using an Internet service provider to connect through the Internet).

[0125] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present invention. In this regard, each box in the flow chart or block diagram can represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flow chart, and the combination of the boxes in the block diagram or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0126] It will be appreciated by those skilled in the art that the features described in the various embodiments of the present invention may be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, without departing from the spirit and teachings of the present invention, the features described in the various embodiments of the present invention may be combined and / or combined in various ways. All of these combinations and / or combinations fall within the scope of the present invention.

[0127] The embodiments of the present invention are described above. However, these embodiments are only for the purpose of illustration, and are not intended to limit the scope of the present invention. Although each embodiment is described above, it does not mean that the measures in each embodiment cannot be used in combination advantageously. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A long-distance single-photon radar large field of view high-resolution rapid imaging method, characterized in that: The method comprises: Constructing a long-distance single-photon large-field-of-view scanning imaging system based on a two-dimensional dual-axis turntable and an array single-photon detector, and configuring the long-distance single-photon large-field-of-view scanning imaging system; The long-distance single-photon large-field-of-view scanning imaging system is used to control the array single-photon detector to scan the panoramic pixel points of the target object in a raster-type continuous scanning manner by setting the motion mode of the two-dimensional dual-axis turntable, so as to obtain the large-field-of-view panoramic single-photon detection data of the target object; Performing real-time data compression processing based on resampling on the large-field panoramic single-photon detection data to restore the image of the target object and obtain a real image of the target object; Among them, performing real-time data compression processing based on resampling on the large-field panoramic single-photon detection data to complete image restoration of the target object to obtain a real image of the target object includes: Performing preliminary noise filtering on the large-field panoramic single-photon detection data in spatial and temporal dimensions to obtain noise-filtered large-field panoramic single-photon detection data; By setting different resampling periods and repeatedly performing resampling operations and convex optimization reconstruction operations on the noise-filtered large-field panoramic single-photon detection data using the different resampling periods, a target image of the target object at the different resampling periods is obtained; The target images of the target object at the different resampling periods are solved for common multiples to obtain a real image of the target object.

2. The method according to claim 1, characterized in that: The long-distance single-photon large-field scanning imaging system based on a two-dimensional dual-axis turntable and an array single-photon detector includes: The long-distance single-photon large-field scanning imaging system is constructed by using the two-dimensional dual-axis turntable, the array single-photon detector, the laser, the transmitting antenna, the receiving antenna and the combined spectral filter.

3. The method according to claim 2, characterized in that Configuring the long-distance single-photon large-field scanning imaging system includes: A laser with a preset atmospheric transmittance is selected as a light source at the transmitting end of the long-distance single-photon large-field-of-view scanning imaging system; Using the transmitting antenna to adjust the divergence angle and direction of the outgoing light beam from the laser; A single-photon array detector with a preset working band is used as the array single-photon detector of the long-distance single-photon large-field scanning imaging system; The solar background noise is suppressed by combining spectral filters, and the signal photons diffusely reflected by the target object are collected by the receiving antenna; The two-dimensional dual-axis turntable is designed based on a horizontal structure and is controlled by a stepper motor. The two-dimensional dual-axis turntable is used to control the scanning of the long-distance single-photon large-field-of-view scanning imaging system along the azimuth axis and the pitch axis, wherein the azimuth axis and the pitch axis pass through the optical axis of the long-distance single-photon large-field-of-view scanning imaging system.

4. The method according to claim 1, characterized in that The long-distance single-photon large-field-of-view scanning imaging system is used to control the array single-photon detector to scan the panoramic pixel points of the target object in a raster-type continuous scanning manner by setting the motion mode of the two-dimensional dual-axis turntable, and the large-field-of-view panoramic single-photon detection data of the target object is obtained, including: Setting the motion mode of the two-dimensional dual-axis turntable to eliminate image distortion during scanning, and defining the same area of ​​the target object in the imaging scene as a panoramic pixel point; Based on the motion mode of the two-dimensional dual-axis turntable, the array single-photon detector is controlled to perform raster-type continuous scanning on all panoramic pixel points of the target object; The panoramic scanning data generated by all panoramic pixel points of the target object in the raster-type continuous scanning process are processed to obtain the large-field panoramic single-photon detection data.

5. The method according to claim 4, characterized in that Setting the motion mode of the two-dimensional dual-axis turntable includes: The two-dimensional dual-axis turntable is set to perform raster scanning so as to switch to the initial position of the next line to continue scanning when scanning to the end of the line; Setting the scanning start and end points of the two-dimensional dual-axis turntable outside the area to be imaged, and discarding the data obtained outside the area to be imaged; The two-dimensional dual-axis turntable is used to set a scanning overlap area between the upper and lower scanning areas to facilitate image stitching in the data processing stage.

6. The method according to claim 4, characterized in that The panoramic scanning data generated by all panoramic pixel points of the target object in the raster-type continuous scanning process are processed to obtain the large-field panoramic single-photon detection data, including: For the same row of panoramic scanning data in the raster-type continuous scanning process, the echo signals generated by detecting the panoramic pixel points of the target object by different array detection pixels of the array single-photon detector are collected, and histogram statistics are performed based on the flight time of the photons to obtain a single row of large-field panoramic single-photon detection data; For multiple lines of panoramic scanning data in the raster-type continuous scanning process, based on the normalized cross-correlation method, the multiple lines of panoramic scanning data are spliced ​​using the overlapping areas between the multiple lines to obtain multiple lines of large-field-of-view panoramic single-photon detection data.

7. The method according to claim 6, characterized in that For multiple lines of panoramic scanning data in the raster-type continuous scanning process, based on the normalized cross-correlation method, the overlapping areas between multiple lines are used to perform data splicing on the multiple lines of panoramic scanning data to obtain multiple lines of large-field panoramic single-photon detection data including: For the panoramic scanning data between the upper and lower rows, the single photon echo signal of the upper row is used as the reference result, and the single photon echo signal of the lower row is used as the floating result; The normalized cross-correlation method is used to calculate the correlation between the upper and lower rows of panoramic scanning data, and based on the correlation, the panoramic scanning data with corresponding positions are merged to obtain the multiple rows of large-field panoramic single-photon detection data.

8. The method according to claim 1, characterized in that: The large-field panoramic single-photon detection data is subjected to preliminary noise filtering in the spatial dimension and the temporal dimension, and the noise-filtered large-field panoramic single-photon detection data is obtained, which includes: Performing data density statistics on the large-field-of-view panoramic single-photon detection data in a spatial dimension to obtain a spatial density distribution function of the large-field-of-view panoramic single-photon detection data; Setting a spatial density threshold, and performing a zeroing operation on data positions corresponding to the spatial density distribution function being lower than the spatial density threshold; Performing pixel merging on the large-field panoramic single-photon detection data in a time dimension to obtain a time density distribution function; A time density threshold is set, a data position corresponding to a time density distribution function being lower than the time density threshold is determined, and a zeroing operation is performed on the large-field panoramic single-photon detection data corresponding to the determined data position.

9. The method according to claim 1, characterized in that: By setting different resampling periods and repeatedly performing resampling operations and convex optimization reconstruction operations on the noise-filtered large-field panoramic single-photon detection data using the different resampling periods, the target images of the target object at the different resampling periods are obtained, including: Setting a resampling period of the current stage, and using the resampling period of the current stage to resample the large-field panoramic single-photon detection data after noise filtering; Performing convex optimization reconstruction on the resampled large-field panoramic single-photon detection data, and constraining the convex optimization reconstruction process by introducing a penalty term, to obtain a target image of the target object at the current stage; The resampling period setting operation, the resampling operation and the convex optimization reconstruction operation are repeatedly performed to obtain the target image of the target object at the different resampling periods.

Images