Multi-view-field parallel single-pixel imaging system and method

Abstract

The invention provides a multi-view-field parallel single-pixel imaging system and method, and the system comprises an imaging unit which is used for imaging different regions of a target object to different coding positions of a coding disc; the coding disc is used for changing the transmission intensity of each imaging light beam by using a cyclic orthogonal coding matrix to obtain a corresponding modulated optical signal; the driving device is used for driving the coding disc to rotate at a constant speed; the plurality of photoelectric detectors are used for performing photoelectric conversion on each modulated optical signal to obtain a corresponding photocurrent signal; the acquisition and reconstruction device is used for acquiring each light current signal; the image obtaining module is used for obtaining a plurality of reconstructable object images; and the image splicing module is also used for splicing the plurality of reconstructable object images to obtain a two-dimensional image of the target object. The technical problems that in the prior art, the imaging speed and image pixels of a single-pixel imaging technology are mutually restricted, and the number of pixels is small during real-time imaging can be solved.

Description

Technical Field

[0001] The present invention relates to the technical fields of photoelectric detection, computational imaging and digital image processing, and in particular to a multi-field parallel single-pixel imaging system and method. Background Art

[0002] In the single-pixel imaging technology in the field of computational imaging, structured light or coded modulation is used, and the spatial light modulation device is the core device. The spatial light modulator is used to realize the encoding of the light field, so that the imaging technology that was originally only possible with a two-dimensional array or point-by-point scanning can be realized through a single-pixel detector. Existing single-pixel cameras generally use digital micromirror devices as modulation encoders for the light field. In recent years, some people have proposed using two-dimensional disk encoding as a spatial light field modulation device. Compared with the complex circuit system of digital micromirror devices, the cost of switching encoding by rotating the disk is lower and the manufacturing method is easier. Therefore, compared with the imaging of array photosensitive chips, the technical advantages of single-pixel imaging are fast imaging speed, simple process, and no need for complex chip array processes.

[0003] Whether in the visible light band or in other bands such as near-infrared, the significant advantage of single-pixel imaging is its fast imaging speed, which can achieve imaging of high-speed moving targets. However, unlike the increasingly clear and high-resolution images obtained by digital cameras, the number of pixels and imaging speed of single-pixel imaging are mutually restricted. The existing imaging pixels are generally between 4096 and 16384 pixels, which seriously restricts the large-scale application of single-pixel imaging technology in industry, military and daily life. In particular, the existing array camera imaging technology in non-visible light bands has not yet been popularized. For example, the price of cameras in the near-infrared and mid-wave infrared bands is still relatively high, and they are mainly used in the industrial and military fields.

[0004] Therefore, increasing the number of existing single-pixel imaging pixels without reducing the imaging time is an urgent problem that needs to be solved in this field. Summary of the invention

[0005] The present invention provides a multi-field parallel single-pixel imaging system and method, which can solve the technical problem that the imaging speed and image pixels of the single-pixel imaging technology in the prior art are mutually restricted, and there are fewer pixels during real-time imaging.

[0006] According to one aspect of the present invention, a multi-field parallel single-pixel imaging system is provided, the system comprising:

[0007] An imaging unit, used to image different regions of the target object to different encoding positions of the encoding disk, wherein the target object is two-dimensional, the imaging unit has at least two imaging beams, and the field of view of the imaging unit covers the entire encoding region of the encoding disk;

[0008] A coding disk, on which a cyclic orthogonal coding matrix is ​​engraved, for changing the transmission intensity of each imaging light beam using the cyclic orthogonal coding matrix to obtain a corresponding modulated light signal;

[0009] A driving device, used for driving the encoding disc to rotate at a constant speed;

[0010] A plurality of photodetectors, used to perform photoelectric conversion on each modulated light signal to obtain a corresponding photocurrent signal, wherein the number of the photodetectors is the same as the number of imaging light beams of the imaging unit;

[0011] The acquisition and reconstruction device is used to acquire each photocurrent signal according to a preset time interval; to optically multiply the acquired photocurrent signals with the transpose of the encoding matrix corresponding to the acquisition moment to obtain a plurality of reconstructable object images; and to splice the plurality of reconstructable object images to obtain a two-dimensional image of the target object.

[0012] Preferably, the imaging unit comprises a plurality of imaging lenses, each of the imaging lenses has one imaging light beam, and the fields of view of adjacent imaging lenses partially overlap.

[0013] According to another aspect of the present invention, a multi-field parallel single-pixel imaging system is provided, the system comprising:

[0014] An imaging unit, used to image the target object from different viewing angles to different encoding positions of the encoding disk, wherein the target object is three-dimensional and the imaging unit has at least two imaging beams;

[0015] A coding disk, on which a cyclic orthogonal coding matrix is ​​engraved, for changing the transmission intensity of each imaging light beam using the cyclic orthogonal coding matrix to obtain a corresponding modulated light signal;

[0016] A driving device, used for driving the encoding disc to rotate at a constant speed;

[0017] A plurality of photodetectors, used to perform photoelectric conversion on each modulated light signal to obtain a corresponding photocurrent signal, wherein the number of the photodetectors is the same as the number of imaging light beams of the imaging unit;

[0018] The acquisition and reconstruction device is used to acquire each photocurrent signal according to a preset time interval; to optically multiply the acquired photocurrent signals with the transpose of the encoding matrix corresponding to the acquisition moment to obtain a plurality of reconstructable object images; and to fuse the plurality of reconstructable object images to obtain a three-dimensional image of the target object.

[0019] Preferably, the imaging unit comprises a plurality of imaging lenses, and each of the imaging lenses has one imaging light beam.

[0020] Preferably, the imaging unit comprises an imaging lens, and the imaging lens has a plurality of imaging light beams.

[0021] Preferably, the encoding disk is a glass substrate coated with a metal film.

[0022] Preferably, the preset time interval is Δt*f, wherein Δt is the time for switching a column of codes, and f is the sampling frequency of the photodetector.

[0023] According to another aspect of the present invention, a multi-field parallel single-pixel imaging method is provided, wherein the method uses the above-mentioned system to perform single-pixel imaging on a two-dimensional target object, and the method comprises:

[0024] The imaging unit images different regions of the target object onto different encoding positions of the encoding disk;

[0025] The encoding disk uses a cyclic orthogonal encoding matrix to change the transmission intensity of each imaging light beam to obtain the corresponding modulated light signal;

[0026] The driving device drives the encoding disk to rotate at a constant speed;

[0027] A plurality of photodetectors respectively perform photoelectric conversion on each modulated optical signal to obtain a corresponding photocurrent signal;

[0028] The acquisition and reconstruction device acquires each photocurrent signal according to a preset time interval, optically multiplies the acquired photocurrent signals with the transpose of the encoding matrix corresponding to the acquisition moment, obtains a plurality of reconstructable object images, and splices the plurality of reconstructable object images to obtain a two-dimensional image of the target object.

[0029] According to another aspect of the present invention, a multi-field parallel single-pixel imaging method is provided, wherein the method uses the above-mentioned system to perform single-pixel imaging on a three-dimensional target object, and the method comprises:

[0030] The imaging unit images the target object from different viewing angles to different encoding positions of the encoding disk;

[0031] The encoding disk uses a cyclic orthogonal encoding matrix to change the transmission intensity of each imaging light beam to obtain the corresponding modulated light signal;

[0032] The driving device drives the encoding disc to rotate at a constant speed;

[0033] A plurality of photodetectors respectively perform photoelectric conversion on each modulated optical signal to obtain a corresponding photocurrent signal;

[0034] The acquisition and reconstruction device acquires each photocurrent signal according to a preset time interval, optically multiplies the acquired photocurrent signals with the transpose of the encoding matrix corresponding to the acquisition moment, obtains a plurality of reconstructable object images, and fuses the plurality of reconstructable object images to obtain a three-dimensional image of the target object.

[0035] Preferably, each photocurrent signal is obtained by the following formula:

[0036]

[0037] In the formula, I j,i is the photocurrent signal of the jth photodetector, H i (x, y) is the i-th column code of the orthogonal coding matrix, O(x, y) is the reflectivity of the target object, x is the horizontal pixel, and y is the vertical pixel.

[0038] Preferably, each reconstructable object image is obtained by the following formula:

[0039]

[0040] Where, Obj j is the jth reconstructable object image, H i (x, y) is the i-th column code of the orthogonal coding matrix, x is the horizontal pixel, y is the vertical pixel, I j,i is the photocurrent signal of the jth photodetector, and N is the total number of codes in the orthogonal coding matrix.

[0041] The technical solution of the present invention is applied to make full use of the characteristics of the distribution of the disk code in space, and multiple lenses or a single large field of view lens and multiple single-pixel photodetectors are used to image the target in parallel, so that the field of view of the single-pixel imaging is expanded to be equal to the number of pixels of the modulation matrix of the coding plate, the imaging pixels are increased, the observation field of view is increased, and a multi-field imaging effect that exceeds the imaging field of the existing single-pixel solution by several times is achieved, while maintaining the advantage of the fast speed of single-pixel imaging without sacrificing the imaging speed. In addition, since the system is only composed of a coding disk, a drive device, and a single-pixel photodetector, compared with an array camera in the non-visible band, the system has a significant low-cost advantage and practical value.

[0042] The present invention significantly increases the field of view and imaging pixels of single-pixel imaging, and has good application value in non-visible light bands, such as near-infrared bands; it realizes rapid imaging from non-visible light bands to visible light bands without complex computing resource requirements, and the hardware cost of the imaging system is low and easy to implement. The present invention can be applied to the detection and imaging of methane gas, security inspection and flaw detection in terahertz bands and X-ray bands, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the embodiments of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0044] Figure 1 A schematic diagram of the structure of a multi-view parallel two-dimensional single-pixel imaging system provided according to an embodiment of the present invention is shown;

[0045] Figure 2 A schematic structural diagram of a multi-viewing field parallel two-dimensional single-pixel imaging system provided in accordance with another embodiment of the present invention is shown;

[0046] Figure 3 A schematic diagram of the structure of a multi-view parallel three-dimensional single-pixel imaging system provided according to an embodiment of the present invention is shown;

[0047] Figure 4 A schematic diagram of parallel single-pixel imaging fields of view of four fields of view provided according to an embodiment of the present invention is shown;

[0048] Figure 5 A schematic diagram of parallel single-pixel imaging fields of view of M fields of view provided according to an embodiment of the present invention is shown.

[0049] The above drawings include the following reference numerals:

[0050] 1. Imaging unit; 2. Encoder disk; 3. Driving device; 4. Photodetector; 5. Acquisition and reconstruction device; 6. Target object. DETAILED DESCRIPTION

[0051] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in 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.

[0052] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0053] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0054] like Figure 1 and Figure 2 As shown, the present invention provides a multi-field parallel single-pixel imaging system, the system comprising:

[0055] An imaging unit 1 is used to image different regions of a target object 6 to different encoding positions of a coding disc 2, wherein the target object 6 is two-dimensional, the imaging unit 1 has at least two imaging beams, and the field of view of the imaging unit 1 covers the entire encoding region of the coding disc 2;

[0056] The coding disk 2 is engraved with a cyclic orthogonal coding matrix, which is used to change the transmission intensity of each imaging light beam by using the cyclic orthogonal coding matrix to obtain a corresponding modulated light signal;

[0057] A driving device 3, used to drive the encoding disc 2 to rotate at a constant speed; wherein the driving device 3 can be a motor;

[0058] A plurality of photodetectors 4, used for performing photoelectric conversion on each modulated light signal to obtain a corresponding photocurrent signal, wherein the number of the photodetectors 4 is the same as the number of imaging light beams of the imaging unit 1;

[0059] The acquisition and reconstruction device 5 is used to acquire each photocurrent signal according to a preset time interval; to optically multiply the acquired photocurrent signals with the transpose of the encoding matrix corresponding to the acquisition moment to obtain a plurality of reconstructable object images; and to splice the plurality of reconstructable object images to obtain a two-dimensional image of the target object 6.

[0060] The present invention makes full use of the characteristics of the distribution of disk codes in space, uses multiple lenses or a single large field of view lens and multiple single-pixel photodetectors 4 to image the target in parallel, expands the field of view of single-pixel imaging to be equal to the number of pixels of the modulation matrix of the coding plate, increases the imaging pixels, increases the observation field of view, and achieves a multi-field imaging effect that exceeds the imaging field of the existing single-pixel solution by several times, while maintaining the advantage of single-pixel imaging speed without sacrificing imaging speed. In addition, since the system is only composed of a coding disk 2, a drive device 3, and a single-pixel photodetector 4, compared with array cameras in non-visible bands, the system has a significant low-cost advantage and practical value.

[0061] The present invention significantly increases the field of view and imaging pixels of single-pixel imaging, and has good application value in non-visible light bands, such as near-infrared bands; it realizes rapid imaging from non-visible light bands to visible light bands without complex computing resource requirements, and the hardware cost of the imaging system is low and easy to implement. The present invention can be applied to the detection and imaging of methane gas, security inspection and flaw detection in terahertz bands and X-ray bands, etc.

[0062] The present invention also provides a multi-field parallel single-pixel imaging method, the method uses the above-mentioned system to perform single-pixel imaging on a two-dimensional target object 6, the method comprising:

[0063] The imaging unit 1 images different regions of the target object 6 onto different encoding positions of the encoding disk 2;

[0064] The encoding disk 2 uses a cyclic orthogonal encoding matrix to change the transmission intensity of each imaging light beam to obtain a corresponding modulated light signal;

[0065] The driving device 3 drives the encoding disk 2 to rotate at a constant speed;

[0066] A plurality of photodetectors 4 respectively perform photoelectric conversion on each modulated optical signal to obtain a corresponding photocurrent signal;

[0067] The acquisition and reconstruction device 5 acquires each photocurrent signal according to a preset time interval, optically multiplies the acquired photocurrent signals with the transpose of the encoding matrix corresponding to the acquisition moment, obtains a plurality of reconstructable object images, and splices the plurality of reconstructable object images to obtain a two-dimensional image of the target object 6.

[0068] According to an embodiment of the present invention, the imaging unit 1 includes a plurality of imaging lenses, each of which has one imaging light beam, and the fields of view of adjacent imaging lenses partially overlap, thereby synthesizing a larger field of view.

[0069] Wherein, the optical parameters of each imaging lens are the same.

[0070] For example, Figure 1 As shown, the imaging unit 1 uses two imaging lenses, and each imaging lens has one imaging light beam.

[0071] According to an embodiment of the present invention, the imaging unit 1 includes an imaging lens, and the imaging lens has a plurality of imaging light beams, which ensures that the image plane of the imaging lens is distributed at different positions of the encoding disk 2.

[0072] For example, Figure 2 As shown, the imaging unit 1 adopts an imaging lens with a large field of view. The imaging lens with a large field of view has two imaging light beams, and the two fields of view partially overlap.

[0073] According to an embodiment of the present invention, the encoding disk 2 is a glass substrate coated with a metal film.

[0074] Specifically, the metal film can be a chromium metal film, which is processed by photolithography, and has the advantages of high processing accuracy, fast modulation speed and low cost. The encoding of the encoding disk 2 adopts a cyclic orthogonal encoding matrix H, which is characterized in that a new measurement basis can be generated by translating only one column of pixels, and the measurement basis is orthogonal, that is, Where I is the identity matrix.

[0075] According to an embodiment of the present invention, each photocurrent signal is obtained by the following formula:

[0076]

[0077] In the formula, I j,i is the photocurrent signal of the jth photodetector, H i (x, y) is the i-th column code of the orthogonal coding matrix, O(x, y) is the reflectivity of the target object, x is the horizontal pixel, and y is the vertical pixel.

[0078] According to an embodiment of the present invention, each reconstructible object image is obtained by the following formula:

[0079]

[0080] Where, Obj j is the jth reconstructable object image, H i (x, y) is the i-th column code of the orthogonal coding matrix, x is the horizontal pixel, y is the vertical pixel, Ij,i is the photocurrent signal of the jth photodetector, and N is the total number of codes in the orthogonal coding matrix.

[0081] According to an embodiment of the present invention, the preset time interval is Δt*f, wherein Δt is the time for switching a column of codes, and f is the sampling frequency of the photodetector 4 .

[0082] like Figure 3 As shown, the present invention provides a multi-field parallel single-pixel imaging system, the system comprising:

[0083] An imaging unit 1, used for imaging a target object 6 from different viewing angles to different encoding positions of the encoding disk 2, wherein the target object 6 is three-dimensional, and the imaging unit 1 has at least two imaging beams;

[0084] The coding disk 2 is engraved with a cyclic orthogonal coding matrix, which is used to change the transmission intensity of each imaging light beam by using the cyclic orthogonal coding matrix to obtain a corresponding modulated light signal;

[0085] A driving device 3, used to drive the encoding disc 2 to rotate at a constant speed; wherein the driving device 3 can be a motor;

[0086] A plurality of photodetectors 4, used for performing photoelectric conversion on each modulated light signal to obtain a corresponding photocurrent signal, wherein the number of the photodetectors 4 is the same as the number of imaging light beams of the imaging unit 1;

[0087] The acquisition and reconstruction device 5 is used to acquire each photocurrent signal according to a preset time interval; to optically multiply the acquired photocurrent signals with the transpose of the encoding matrix corresponding to the acquisition moment to obtain a plurality of reconstructable object images; and to fuse the plurality of reconstructable object images to obtain a three-dimensional image of the target object 6.

[0088] The present invention makes full use of the characteristics of the distribution of disk codes in space, uses multiple lenses or a single large field of view lens and multiple single-pixel photodetectors 4 to image the target in parallel, expands the field of view of single-pixel imaging to be equal to the number of pixels of the modulation matrix of the coding plate, increases the imaging pixels, increases the observation field of view, and achieves a multi-field imaging effect that exceeds the imaging field of the existing single-pixel solution by several times, while maintaining the advantage of single-pixel imaging speed without sacrificing imaging speed. In addition, since the system is only composed of a coding disk 2, a drive device 3, and a single-pixel photodetector 4, compared with array cameras in non-visible bands, the system has a significant low-cost advantage and practical value.

[0089] The present invention significantly increases the field of view and imaging pixels of single-pixel imaging, and has good application value in non-visible light bands, such as near-infrared bands; it realizes rapid imaging from non-visible light bands to visible light bands without complex computing resource requirements, and the hardware cost of the imaging system is low and easy to implement. The present invention can be applied to the detection and imaging of methane gas, security inspection and flaw detection in terahertz bands and X-ray bands, etc.

[0090] The present invention also provides a multi-field parallel single-pixel imaging method, the method uses the above-mentioned system to perform single-pixel imaging on a three-dimensional target object 6, the method comprising:

[0091] The imaging unit 1 images the target object 6 from different viewing angles to different encoding positions of the encoding disk 2;

[0092] The encoding disk 2 uses a cyclic orthogonal encoding matrix to change the transmission intensity of each imaging light beam to obtain a corresponding modulated light signal;

[0093] The driving device 3 drives the encoding disc 2 to rotate at a constant speed;

[0094] A plurality of photodetectors 4 respectively perform photoelectric conversion on each modulated optical signal to obtain a corresponding photocurrent signal;

[0095] The acquisition and reconstruction device 5 acquires each photocurrent signal according to a preset time interval, optically multiplies the acquired photocurrent signals with the transpose of the encoding matrix corresponding to the acquisition moment, obtains a plurality of reconstructable object images, and fuses the plurality of reconstructable object images to obtain a three-dimensional image of the target object 6.

[0096] According to an embodiment of the present invention, the imaging unit 1 includes a plurality of imaging lenses, and each of the imaging lenses has one imaging light beam.

[0097] Wherein, the optical parameters of each imaging lens are the same.

[0098] For example, Figure 3 As shown, the imaging unit 1 uses two imaging lenses, and each imaging lens has one imaging light beam.

[0099] According to an embodiment of the present invention, the imaging unit 1 includes an imaging lens, and the imaging lens has a plurality of imaging light beams, which ensures that the image plane of the imaging lens is distributed at different positions of the encoding disk 2.

[0100] According to an embodiment of the present invention, the encoding disk 2 is a glass substrate coated with a metal film.

[0101] Specifically, the metal film can be a chromium metal film, which is processed by photolithography, and has the advantages of high processing accuracy, fast modulation speed and low cost. The encoding of the encoding disk 2 adopts a cyclic orthogonal encoding matrix H, which is characterized in that a new measurement basis can be generated by translating only one column of pixels, and the measurement basis is orthogonal, that is, Where I is the identity matrix.

[0102] According to an embodiment of the present invention, each photocurrent signal is obtained by the following formula:

[0103]

[0104] In the formula, I j,i is the photocurrent signal of the jth photodetector, H i (x, y) is the i-th column code of the orthogonal coding matrix, O(x, y) is the reflectivity of the target object, x is the horizontal pixel, and y is the vertical pixel.

[0105] According to an embodiment of the present invention, each reconstructible object image is obtained by the following formula:

[0106]

[0107] Where, Obj j is the jth reconstructable object image, H i (x, y) is the i-th column code of the orthogonal coding matrix, x is the horizontal pixel, y is the vertical pixel, I j,i is the photocurrent signal of the jth photodetector, and N is the total number of codes in the orthogonal coding matrix.

[0108] According to an embodiment of the present invention, the preset time interval is Δt*f, wherein Δt is the time for switching a column of codes, and f is the sampling frequency of the photodetector 4 .

[0109] In order to further understand the present invention, the following Figure 1-Figure 5 The multi-field parallel single-pixel imaging system and method of the present invention are described in detail.

[0110] like Figure 1 As shown, a schematic diagram of the structure of a multi-field parallel two-dimensional single-pixel imaging system is shown.

[0111] exist Figure 1 In the system, the imaging unit 1 includes two imaging lenses with the same optical parameters, which are used to reduce the image of the target object 6 and image it onto the encoder disk 2. The fields of view of the two imaging lenses partially overlap and can be combined into a larger field of view. The specific imaging method of the system is as follows:

[0112] Step S1, different regions of the target object 6 are imaged respectively through two imaging lenses (or more imaging lenses), and the two imaging lenses respectively image the target object 6 to different encoding positions of the circular encoding disk 2, and the encoding disk 2 is engraved with a circulant orthogonal matrix H;

[0113] Step S2: the encoder disk 2 is driven by the motor to rotate at a constant speed. i Switching in sequence, i = 1, 2, 3 ... N, the reflectivity O(x, y) of different parts of the target object 6 (there can also be more target objects 6) is sequentially compared with the encoding matrix H i (x,y) and H i+k (x, y) (there may be more coding areas), k = 1, 2, 3 ... Ni, the modulated optical signal is received by two photodetectors 4 (or more photodetectors 4, which are equal to the number of imaging beams of the imaging lens), forming a photocurrent I 1i and I 2i The modulated signals converged on the two photodetectors 4 realize optical convolution and The two photodetectors 4 can be detectors of any optical band;

[0114] Step S3, a photoelectric detector 4 outputs a photocurrent signal I after photoelectric conversion. 1i , after being photoelectrically converted by another photodetector 4, the photocurrent signal I is output 2i (By analogy, if there are multiple photodetectors 4, multiple photocurrent signals are obtained);

[0115] Step S4: After the encoder disk 2 rotates one circle, the code H of the encoder disk 2 i (x, y) is switched N times in sequence and collected by two photodetectors 4 (if there are multiple detectors, then multiple detectors collect it), i = 1, 2, 3 ... N, and two groups (if there are multiple detectors, then multiple groups) of photocurrent signals will be obtained respectively. The sampling frequency of the two photodetectors 4 is f, and the time for the encoder disk 2 to switch a column of codes is set to △t, then the number of sampling points of the two photodetectors 4 is N*△t*f, so the acquisition and reconstruction system collects two groups of measurement values ​​{I 11 ,I 12 , I 13 , I 14 , . . . , I 1N} and {I 21 ,I 22 , I 23 , I 24 , . . . , I 2N};

[0116] Step S5, the acquisition and reconstruction system converts the acquired measurement values ​​{I 11 ,I 12 , I 13 , I 14 , . . . , I 1N} and {I 21 ,I 22 , I 23 , I 24 , . . . , I 2N} (if there are multiple detectors, then multiple sets of measurements) are respectively related to the transpose H of the encoding matrix H T The object image can be reconstructed by multiplying and Two images (or multiple images if there are multiple detectors);

[0117] In step S6, the acquisition and reconstruction system stitches the two images Obj1 and Obj2 obtained in S5 (or multiple images if there are multiple detectors), and finally obtains an image with an enlarged field of view, thereby increasing the field of view of the traditional single-pixel camera.

[0118] like Figure 2 As shown, a schematic diagram of the structure of a multi-field parallel two-dimensional single-pixel imaging system is shown.

[0119] exist Figure 2 In the system, the imaging unit 1 includes an imaging lens, which is used to reduce the image of the target object 6 and image it onto the encoding disk 2. The imaging light beam of the imaging lens is two beams, which can be combined into a larger field of view. Figure 1 The imaging method is the same as that in the previous example and will not be described again here.

[0120] like Figure 3 As shown, a schematic diagram of the structure of a multi-field parallel three-dimensional single-pixel imaging system is shown.

[0121] exist Figure 3 In the system, the imaging unit 1 includes two imaging lenses with the same optical parameters. The two imaging lenses are simultaneously aimed at the same area of ​​the same object, and single-pixel imaging is performed from different viewing angles. Through the binocular vision method, the imaging results can finally realize three-dimensional imaging of the object to be measured.

[0122] Figure 4 A schematic diagram of parallel single-pixel imaging of four fields of view is shown.

[0123] exist Figure 4 By adding imaging lenses, for example, 4 imaging lenses, a larger field of view can be achieved by stitching single pixel imaging, as shown in the attached figure. Figure 4As shown, the serial numbers 1, 2, 3, and 4 in the left figure respectively represent the corresponding spatial positions of four imaging lenses and four photodetectors 4 placed on the encoding disk 2, and the right figure shows the ranges and mutual relationships of the imaging fields of view 1, 2, 3, and 4 corresponding to the four imaging lenses.

[0124] Figure 5 A schematic diagram of parallel single-pixel imaging of M fields of view is shown.

[0125] exist Figure 5 In the example, the imaging system can be expanded into M fields of view, where M is the maximum number of imaging lenses that can be placed on the actual encoder disk 2, and the corresponding imaging field of view will also increase by about M times. Figure 5 As shown, when M imaging lenses are placed at corresponding positions of the encoding disk 2, single-pixel imaging results of M fields of view can be obtained according to the method described.

[0126] In summary, the present invention provides a multi-field parallel single-pixel imaging system and method, which has the following beneficial effects compared with the prior art:

[0127] (1) Using a metal-film-coated photolithography plate as a modulation device and encoding according to a cyclic orthogonal matrix can save encoding space and disk size, and significantly reduce costs compared to digital micromirror devices;

[0128] (2) A metal-film-coated photolithography plate is used as a modulation device, and the spectral range of the working wavelength is wide, which can achieve high-resolution imaging with a large field of view in non-visible bands such as near-infrared;

[0129] (3) A metal-film-coated photolithography plate is used as a modulation device, which has a natural time synchronization property when rotating. When realizing multi-field imaging, the imaging speed is fast and the solution can be performed in parallel. After aligning the acquisition time of different photodetectors 4, the data can be reused, which improves the signal-to-noise ratio by the square root of the number of detectors, further improving the quality of single-pixel imaging, and the entire system also has the advantage of low-cost imaging.

[0130] Parts of the present invention that are not described in detail are well known to those skilled in the art.

[0131] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0132] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0133] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0134] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A multi-field parallel single-pixel imaging system, characterized in that: The system comprises: An imaging unit, used to image different regions of the target object to different encoding positions of the encoding disk, wherein the target object is two-dimensional, the imaging unit has at least two imaging beams, and the field of view of the imaging unit covers the entire encoding region of the encoding disk; A coding disk, on which a cyclic orthogonal coding matrix is ​​engraved, for changing the transmission intensity of each imaging light beam using the cyclic orthogonal coding matrix to obtain a corresponding modulated light signal; A driving device, used for driving the encoding disc to rotate at a constant speed; A plurality of photodetectors, used to perform photoelectric conversion on each modulated light signal to obtain a corresponding photocurrent signal, wherein the number of the photodetectors is the same as the number of imaging light beams of the imaging unit; The acquisition and reconstruction device is used to acquire each photocurrent signal according to a preset time interval; to optically multiply the acquired photocurrent signals with the transpose of the encoding matrix corresponding to the acquisition moment to obtain a plurality of reconstructable object images; and to splice the plurality of reconstructable object images to obtain a two-dimensional image of the target object.

2. The system according to claim 1, characterized in that The imaging unit includes a plurality of imaging lenses, each of which has one imaging light beam, and the fields of view of adjacent imaging lenses partially overlap.

3. A multi-field parallel single-pixel imaging system, characterized in that: The system comprises: An imaging unit, used to image the target object from different viewing angles to different encoding positions of the encoding disk, wherein the target object is three-dimensional and the imaging unit has at least two imaging beams; A coding disk, on which a cyclic orthogonal coding matrix is ​​engraved, for changing the transmission intensity of each imaging light beam using the cyclic orthogonal coding matrix to obtain a corresponding modulated light signal; A driving device, used for driving the encoding disc to rotate at a constant speed; A plurality of photodetectors, used to perform photoelectric conversion on each modulated light signal to obtain a corresponding photocurrent signal, wherein the number of the photodetectors is the same as the number of imaging light beams of the imaging unit; The acquisition and reconstruction device is used to acquire each photocurrent signal according to a preset time interval; to optically multiply the acquired photocurrent signals with the transpose of the encoding matrix corresponding to the acquisition moment to obtain a plurality of reconstructable object images; and to fuse the plurality of reconstructable object images to obtain a three-dimensional image of the target object.

4. The system according to claim 3, characterized in that The imaging unit includes a plurality of imaging lenses, and each imaging lens has one imaging light beam.

5. The system according to claim 1 or 3, characterized in that: The imaging unit comprises an imaging lens, and the imaging lens has a plurality of imaging light beams.

6. The system according to claim 1 or 3, characterized in that: The encoding disc is a glass substrate coated with a metal film.

7. The system according to claim 1 or 3, characterized in that: The preset time interval is Δt*f, wherein Δt is the time for switching a column of codes, and f is the sampling frequency of the photoelectric detector.

8. A multi-field parallel single-pixel imaging method, characterized in that: The method uses the system of claim 1 to perform single-pixel imaging on a two-dimensional target object, and the method comprises: The imaging unit images different regions of the target object onto different encoding positions of the encoding disk; The encoding disk uses a cyclic orthogonal encoding matrix to change the transmission intensity of each imaging light beam to obtain the corresponding modulated light signal; The driving device drives the encoding disk to rotate at a constant speed; A plurality of photodetectors respectively perform photoelectric conversion on each modulated optical signal to obtain a corresponding photocurrent signal; The acquisition and reconstruction device acquires each photocurrent signal according to a preset time interval, optically multiplies the acquired photocurrent signals with the transpose of the encoding matrix corresponding to the acquisition moment, obtains a plurality of reconstructable object images, and splices the plurality of reconstructable object images to obtain a two-dimensional image of the target object.

9. A multi-field parallel single-pixel imaging method, characterized in that: The method uses the system of claim 3 to perform single-pixel imaging on a three-dimensional target object, and the method comprises: The imaging unit images the target object from different viewing angles to different encoding positions of the encoding disk; The encoding disk uses a cyclic orthogonal encoding matrix to change the transmission intensity of each imaging light beam to obtain the corresponding modulated light signal; The driving device drives the encoding disc to rotate at a constant speed; A plurality of photodetectors respectively perform photoelectric conversion on each modulated optical signal to obtain a corresponding photocurrent signal; The acquisition and reconstruction device acquires each photocurrent signal according to a preset time interval, optically multiplies the acquired photocurrent signals with the transpose of the encoding matrix corresponding to the acquisition moment, obtains a plurality of reconstructable object images, and fuses the plurality of reconstructable object images to obtain a three-dimensional image of the target object.

10. The method according to claim 8 or 9, characterized in that: Each photocurrent signal is obtained by the following formula: In the formula, I j,i is the photocurrent signal of the jth photodetector, H i (x, y) is the i-th column code of the orthogonal coding matrix, O(x, y) is the reflectivity of the target object, x is the horizontal pixel, and y is the vertical pixel.

11. The method according to claim 8 or 9, characterized in that: Each reconstructable object image is obtained by the following formula: Where, Obj j is the jth reconstructable object image, H i (x, y) is the i-th column code of the orthogonal coding matrix, x is the horizontal pixel, y is the vertical pixel, I j,i is the photocurrent signal of the jth photodetector, and N is the total number of codes in the orthogonal coding matrix.

Images