Single-pixel radiation imaging method and system based on rotation measurement

Abstract

The present invention discloses a single-pixel radiation imaging method and system based on rotational measurement, which determines the beam region and boundary line in an image; calculates the area of the beam passing through each pixel of the object at different angles according to the situation of the boundary line passing through the pixels; obtains the ray field after the coded aperture plate is rotationally modulated according to a preset angle; traverses all pixels in a loop to obtain the system matrix, and uses a reconstruction algorithm combined with the system matrix to obtain the reconstructed image of the object. This method provides a novel recovery scheme, increases the dimension of the change in the measurement form, improves the translational measurement to rotational measurement, realizes equivalent modulation by using the spatial variation of a single coded aperture plate, and constructs an algorithm to obtain the system matrix at different angles. It realizes sufficient modulation of the ray field through the rotational multiplexing of a single coded aperture plate, uses very few coded aperture plates to complete the modulation, and obtains high-quality imaging results. It realizes multiple modulations of the ray field, improves the utilization rate of a single coded aperture plate, and achieves the purpose of reducing costs and manufacturing difficulties.

Description

Technical Field

[0001] The present invention relates to the technical field of single-pixel radiation imaging, and in particular to a single-pixel radiation imaging method and system based on rotation measurement. Background Art

[0002] Single-pixel imaging classified as radiation imaging is different from general single-pixel imaging. Since the penetrating power of radiation is much stronger than that of light, the encoding of incident radiation can only be achieved through the physical attenuation of radiation in the encoding plate.

[0003] Considering the general single-pixel radiation imaging with a pixel count of k*k, it is necessary to produce all the different code plates required for each measurement, and complete the modulation of the rays through mechanical movement. The code plates required for this type of imaging have a pixel count of up to k^4. The manufacturing difficulty and cost of a large number of code plates are very high, and their mechanical movement also greatly prolongs the measurement time.

[0004] One solution to achieve fast measurement is that it is not necessary to completely move or replace a sub-encoding plate each time. After each measurement, only one column needs to be moved to consider the modulation effect as changed. Experiments have shown that this type of solution takes into account the miniaturization of the encoding plate while ensuring the imaging quality. In general, this type of solution greatly reduces the size of the encoding plate (manufacturing difficulty) while achieving fast measurement. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a novel single-pixel radiation imaging method based on rotation measurement, which utilizes a rotating encoding plate to perform single-pixel radiation imaging.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The single-pixel radiation imaging method based on rotation measurement provided by the present invention comprises the following steps:

[0008] Determining the boundary lines of the beam area;

[0009] According to the crossing of the upper and lower boundary lines of the system matrix, the area of ​​each pixel of the object passed by the beam at different angles is calculated;

[0010] Obtaining the ray field after the sub-encoding plate is rotated and modulated according to a preset angle;

[0011] Use the ray fields of all sub-encoding plates to obtain the system matrix;

[0012] Use the reconstruction algorithm and the system matrix to reconstruct the object image.

[0013] Further, the encoding plate includes a number of sub-encoding plates designed in a preset manner, which are used to partially block the rays incident on the sub-encoding plates; so that the rays are modulated by each sub-encoding plate to obtain a ray field with a beam-like distribution.

[0014] Further, the sub-encoding plate is a striped encoding plate; and regions allowing the rays to pass through are provided in the striped encoding plate.

[0015] Further, the beam region and the boundary line are calculated in the following manner:

[0016] The image region is divided into a number of pixel grid regions;

[0017] The upper boundary ray and the lower boundary ray are calculated respectively according to the beam boundary equation;

[0018] The beam region is determined according to the upper boundary ray and the lower boundary ray;

[0019] Further, the system matrix is calculated in the following manner:

[0020] Traverse and calculate the areas of the beams (ray fields) passing through each pixel of the object at different angles along the upper and lower boundary lines;

[0021] Correct the areas of the rays passing through the pixels according to the situations of the two boundary lines passing through the pixels;

[0022] The system matrix is obtained using the ray fields of all the sub-encoding plates.

[0023] Further, the beam boundary is calculated in the following manner:

[0024] Let the beam boundary equation be y = mx + b, and the longitudinal intercepts of its intersection with a certain pixel be d1 and d2 successively, where the lower left vertex of the pixel is (x a , y j ), then the two intercept expressions are:

[0025] d1 = mx a + b - y j

[0026] d2 = m(x a + δ) + b - y j

[0027] Determine the ray situation and the pixel numbers passed through according to d1 and d2;

[0028] Among them, d1 represents the intercept of the upper boundary line on the pixel; d2 represents the intercept of the lower boundary line on the pixel; δ represents the side length of a unit pixel; m represents the slope of the current beam; b represents the intercept of the current ray on the vertical axis of the coordinate system;

[0029] Further, the areas where the upper boundary ray and the lower boundary ray pass through the pixels are calculated respectively according to the intersection of the ray and the passed pixels, which specifically includes the following four cases:

[0030] The first case:

[0031] Lower boundary:

[0032] Upper boundary:

[0033] The second case:

[0034] Lower boundary:

[0035] Upper boundary:

[0036] The third case:

[0037] Lower boundary:

[0038] Upper boundary:

[0039] The fourth case:

[0040] Lower boundary:

[0041] Upper boundary:

[0042] Among them, S △ and S □ represent the area of the overlapping part between the beam region and the pixel.

[0043] A matrix P is established as the system matrix to record the modulation effects of all encoding plates. One row of P i records the modulation effect after one rotation of a sub-encoding plate.

[0044] Further, the system matrix is updated in the following manner:

[0045] It is classified according to the situation of the pixels passed through between the upper and lower boundary rays;

[0046] Traverse the pixel numbers passed through along the boundary line. For different passing situations of the upper and lower boundary rays, the area at the corresponding pixel position in the system matrix is updated according to the classification;

[0047] Further, classification is performed according to the situation of the pixels passed through between the two boundary rays, which specifically includes three cases: 1) The two rays pass through the same pixel grid; 2) They pass through two different pixels respectively and there are no pixels that are not passed through between the two different pixels; 3) They pass through two different pixels respectively and there are other pixels that are not passed through between the two different pixels.

[0048] The area of the corresponding pixel in the system matrix is updated in the following manner:

[0049] (1) The two rays pass through the same pixel grid;

[0050] W i = W 1-i + W 2-i - δ 2 ;

[0051] Among them, W i represents the modulation effect on the i-th pixel; W 1-i represents the area of the lower boundary on the i-th pixel; W 2-i represents the area of the upper boundary on the i-th pixel;

[0052] (2) They pass through two different pixels respectively and there are no pixels that are not passed through between the two different pixels, and the modulation effect of the pixels that meet the conditions remains unchanged;

[0053] (3) They pass through two different pixels respectively and there are other pixels that are not passed through between the two different pixels, then the area of the spatial domain element among them is recorded as W i = δ 2 .

[0054] The single-pixel radiation imaging system based on rotational measurement provided by the present invention includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the above method is implemented.

[0055] The beneficial effects of the present invention are as follows:

[0056] The novel single-pixel radiation imaging method and system based on rotational measurement provided by the present invention determine the beam region and boundary line in the image; calculate the area of the beam passing through each pixel of the object at different angles according to the situation of the boundary line passing through the pixels; obtain the ray field after the sub-coded plate is rotationally modulated according to a preset angle; loop through all pixels to obtain the system matrix, and use a reconstruction algorithm combined with the system matrix to obtain the reconstructed image of the object. This method provides a novel imaging scheme, increases the dimension of the change in the measurement form, improves the translational measurement to rotational measurement, realizes ray modulation by using the spatial variation of a single sub-coded plate, and constructs an algorithm to obtain the system matrix at different angles. It realizes the rotational multiplexing of a single sub-coded plate, improves the utilization rate of a single sub-coded plate, completes the modulation of rays with very few sub-coded plates, achieves the purpose of reducing costs and manufacturing difficulties, and simultaneously obtains high-quality imaging results.

[0057] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be learned from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following specification. Brief Description of the Drawings

[0058] To make the objectives, technical solutions, and beneficial effects of the present invention clearer, the present invention provides the following drawings for description:

[0059] Figure 1 Schematic diagram of parallel beam CT in rotation / translation mode.

[0060] Figure 2 Flowchart of the novel single-pixel radiation imaging method based on rotational measurement.

[0061] Figure 3 Display diagram of a single-column striped coded plate with a resolution of 8*8.

[0062] Figure 4 Relationship diagram of the beam model and the object (pixel).

[0063] Figure 5 Relative relationship diagram of the ray and the pixel.

[0064] Figure 6 Display diagram of the single-pixel radiation imaging result under full sampling.

[0065] Figure 7 Single-pixel radiation imaging quality evaluation form.

[0066] Figure 8 Display diagram of the single-pixel radiation imaging result under undersampling.

[0067] Figure 9 It is the evaluation value of the single-pixel radiation imaging quality for each scheme. Specific implementation mode

[0068] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the specific embodiments cited do not limit the present invention.

[0069] Embodiment 1

[0070] As Figure 1 shown, Figure 1 The schematic diagram of parallel beam CT in the rotation / translation mode shows the overall concept of this embodiment. In parallel beam CT, each ray optical path follows the Lambert-Beer law:

[0071]

[0072] In the formula, d is the thickness, and μ j is the attenuation coefficient, and I0 represents the incident intensity of the ray;

[0073] In the parallel beam CT imaging in the rotation / translation mode, each time of detection, the detector receives the sum of the ray intensities after the beam passes through the object, that is, the detector obtains a value each time of detection; at the same time, when each sub-coding plate in the single-pixel imaging is measured, the detector obtains a total intensity value.

[0074] Therefore, using the idea of rotational measurement in the existing CT imaging, a striped coding plate is designed to imitate the form of obtaining data in CT imaging. After a cluster of light beams passing through the stripes of the coding plate act on the object to be measured, the detector in the single-pixel imaging system obtains the total intensity value.

[0075] As Figure 2 shown, the novel single-pixel radiation imaging method based on rotational measurement provided in this embodiment includes the following steps:

[0076] Determine the boundary line of the beam area;

[0077] Circularly traverse along the upper and lower boundary lines of the beam to calculate the areas of each pixel of the object passing through the beam area at different angles;

[0078] Obtain the modulation effect after the sub-coding plate is rotated according to the preset angle;

[0079] Use the ray fields of all sub-coding plates to obtain the system matrix;

[0080] Use the reconstruction algorithm and the system matrix for reconstruction and recovery.

[0081] The beam model establishment process and its calculation method in this embodiment:

[0082] The coding plate in this embodiment includes a plurality of sub-coding plates designed in a preset manner, which are used to partially block the rays directed toward the sub-coding plates, so that the rays are modulated by the sub-coding plates to obtain a beam-shaped pattern;

[0083] The sub-coding plate in this embodiment is a stripe-shaped coding plate; the stripe-shaped coding plate is provided with a column of areas that allow rays to pass through;

[0084] The coding plate in this embodiment adopts a striped coding plate, such as Figure 3 As shown, Figure 3 This is a diagram showing all stripe-shaped coding plates with a resolution of 8*8. In this embodiment, a single-row stripe-shaped coding plate designed to imitate the CT data acquisition format is used as the coding plate for rotation measurement. For an imaging object with a resolution of 8*8, a total of 8 single-row stripe-shaped coding plates are required, and the specific composition is as follows: Figure 3 As shown:

[0085] At a certain angle, the intensity distribution of the ray field will change dramatically after being modulated by the striped coding plate, as shown in the figure below. Due to the striped coding plate, only one or more columns of areas are not filled with material (only one column in this embodiment), and the rays can pass through intact, while other areas of the coding plate will be blocked by the material. This results in that after the ray field is modulated, only one or more columns of areas still have ray particles, and the whole presents a beam shape.

[0086] like Figure 4 As shown, Figure 4 is the relationship diagram between the beam model and the object; the image area is divided into N = n × n pixel areas, and it is assumed that the side length of each pixel is δ, the shaded area is the ray field distribution area after modulation by the coding plate, that is, the beam area, and τ represents the distance between the upper and lower boundaries of the beam. It is worth noting that the beam passes through pixels differently at different angles. To obtain high-quality imaging results, the most important thing is to accurately calculate the area of ​​each pixel of the object that the beam passes through at different angles, and describe the modulation effect of the coding plate on the rays.

[0087] Therefore, it is necessary to establish a beam model to accurately calculate the system matrix in the form of rotation measurement. The beam model calculation method includes boundary analysis and calculation, loop calculation and fast traversal;

[0088] The beam area and boundary line in this embodiment are calculated as follows:

[0089] Divide the image area into a number of pixel grid areas;

[0090] Calculate the upper boundary ray and the lower boundary ray respectively according to the beam boundary equation;

[0091] Determine the beam region according to the upper boundary ray and the lower boundary ray;

[0092] In this embodiment, the system matrix is calculated in the following manner:

[0093] Traverse along the upper and lower boundary lines of the shot to calculate the area of the beam (ray field) passing through each pixel of the object at different angles;

[0094] Correct the area of the ray passing through the pixel according to the situation of the two boundary lines passing through the pixel;

[0095] Obtain the system matrix using the ray fields of all sub-encoding plates.

[0096] The beam boundary in this embodiment is calculated in the following manner:

[0097] The intersection area of the beam at each angle with the pixel is the modulation effect of the stripe (beam)-shaped encoding plate; for each beam with a width of δ, it is enclosed by the upper and lower boundary lines. Among them, Figure 4 is a part of the n×n system matrix, the red font (such as j-n, etc.) is the pixel number, and J is the pixel to be discussed (i.e., A'GJB'); there are four cases of the intersection of the ray with the pixel J (rays I, II... V). For pixel J, the coordinates of its lower left corner B′ are denoted as (x a , y j ). Taking this point as the origin, calculate the intercepts of the boundary lines on the pixel. Assuming the beam boundary equation is y = mx + b, d1 is the intercept of the upper boundary line on B′A′, and d2 is the intercept of the lower boundary line on B′A′. The intercepts with a certain pixel are d1 and d2 in sequence, then the two intercept expressions are:

[0098] d1 = mx a + b - y j (2)

[0099] d2 = m(x a + δ) + b - y j (3)

[0100] Among them, d1 represents the intercept of the upper boundary line on the pixel; d2 represents the intercept of the lower boundary line on the pixel; δ represents the side length of a unit pixel; m represents the slope of the current beam; b represents the intercept of the current ray on the vertical axis of the coordinate system;

[0101] Determine the ray situation and the pixel number passed through according to d1 and d2; that is, according to the positive and negative of d1 and d2, the ray situation and the next pixel number to be passed through (traversal order) can be determined. Specifically, as shown in Table 1, where δ represents the pixel side length.

[0102] As Figure 5 shown, Figure 5It is a diagram of the relative relationship between the ray and the pixel. The areas of the upper boundary ray and the lower boundary ray passing through the pixel are calculated respectively according to the intersection situation of the beam and the pixels it passes through;

[0103] In this embodiment, according to d1 and d2, the ray situation and the pixel numbers that will be passed through next can be determined, as shown in Table 1 specifically:

[0104] Table 1

[0105]

[0106] Among them, J represents the pixel number, and n represents the size of the system matrix (n×n);

[0107] In this embodiment, the areas of the upper boundary ray or the lower boundary ray passing through the pixel are calculated according to the intersection area of the beam and the pixel. For rays (situations) I, II…V, according to whether it is the upper and lower boundaries of the beam, the areas of the beam and the pixel are discussed as follows, including the following four situations specifically:

[0108] The first situation:

[0109] Lower boundary:

[0110] Upper boundary:

[0111] The second situation:

[0112] Lower boundary:

[0113] Upper boundary:

[0114] The third situation:

[0115] Lower boundary:

[0116] Upper boundary:

[0117] The sixth situation:

[0118] Lower boundary:

[0119] Upper boundary:

[0120] Among them, S, S, etc. represent Figure 5 the area of the overlapping part of the beam region and the pixel in the middle;

[0121] △□

[0122] A matrix P is established as the system matrix to record the modulation effects of all encoding plates. P iMake a row of P to record the modulation effect after a single rotation of a sub-coding plate.

[0123] Through the above formula, it is possible to calculate the area of the pixels through which the boundary of the beam region passes after the striped coding plate rotates by a certain angle, as well as the classification of the boundary. According to the ray classification, the next pixel to be calculated is determined for recursion until the beam exceeds the object space. Subsequently, the pixel numbers passed by the beam and the area of the pixels passed by the beam region are obtained.

[0124] The system matrix provided in this embodiment is updated in the following manner:

[0125] Classify according to the situation of the pixels passed through between the two boundary rays above and below. Specifically, it includes three situations: 1) The two rays pass through the same pixel grid; 2) They pass through two different pixels respectively and there are no pixels that are not passed through between the two different pixels; 3) They pass through two different pixels respectively and there are other pixels that are not passed through between the two different pixels.

[0126] Traverse the pixel numbers passed through along the boundary line. For different passing situations of the upper and lower boundary rays, the area at the corresponding pixel position in the system matrix is updated as follows:

[0127] (1) The two rays pass through the same pixel grid;

[0128] When the two rays pass through the same pixel grid, that is, in the first case, calculate the system matrix, that is, consider the "total" area of the beam on the pixel by integrating the upper and lower boundary lines.

[0129] W i =W 1-i +W 2-i -δ 2 (14)

[0130] Among them, the pixel W i represents the modulation effect on the i-th pixel; W 1-i represents the area of the lower boundary on the i-th pixel; W 2-i represents the area of the upper boundary on the i-th pixel;

[0131] (2) Pass through two different pixels respectively and there are no pixels that are not passed through between the two different pixels. The modulation effect of the pixels that meet the conditions remains unchanged;

[0132] (3) Pass through two different pixels respectively and there are other pixels that are not passed through between the two different pixels. For the airspace elements among them, the area is recorded as W i =δ 2 ;

[0133] Embodiment 2

[0134] The novel single-pixel radiation imaging method based on rotational measurement provided by this embodiment is illustrated through the following specific process:

[0135] Verify the feasibility of the single-pixel radiation imaging scheme under rotational measurement. For this purpose, 32 strip-shaped encoding plates are used, and each measurement is taken when the encoding plate rotates 5.625° (180 / 32), with a total of 1024 measurements.

[0136] Figure 6 It is a display diagram of the single-pixel radiation imaging result under full sampling; among them, Figure (a) is the original image, and for comparison in (b), it shows the restoration effect of a general imaging system (using a Hadamard encoding plate for full sampling and the compressive sensing algorithm for restoration), (c) is the restoration effect using the traditional second-order correlation algorithm under rotational measurement, and (d) is the restoration result of the compressive sensing algorithm under rotational measurement.

[0137] Figure 7 It is a single-pixel radiation imaging quality evaluation table; it can be seen from the figure that the novel single-pixel radiation imaging method of measuring with a rotating strip-shaped encoding plate and calculating the system matrix using a beam model is feasible. The introduction of the compressive sensing algorithm can also significantly improve the image quality. Considering practical applications, experiments under undersampling were conducted; in the traditional Hadamard single-pixel scheme, using the "RR sequence" at a sampling rate of about 20% can obtain good imaging quality. In the corresponding rotational measurement scheme, each strip-shaped encoding plate is only measured 7 times. The imaging results of the two schemes are shown in the following figure: Figure 8 It is a display diagram of the single-pixel radiation imaging result under undersampling, Figure 8 Among them, the right figure is the restoration result of the traditional Hadamard single-pixel scheme using the compressive sensing algorithm; the left figure is the restoration result of the rotational encoding plate measurement scheme using the compressive sensing algorithm (subjectively, the imaging effect of the latter is better than that of the former).

[0138] Figure 9 It is the single-pixel radiation imaging quality evaluation value of each scheme; it can be seen that when the sampling rate is 20%, the edge of the imaging result of the Hadamard single-pixel using the RR sequence is already blurred to a certain extent compared with the original image. Compared with the situation under full sampling, the PSNR of the image also drops from the original 24.3 to 18.9, a decrease of 22.2%. For the novel single-pixel imaging result, there is not much change in the intuitive feeling. Objectively, the PSNR of the image drops from the original 37.8 to 32.6, only a decrease of 13%. The greater advantage of the latter (rotational measurement scheme) is that only 32 sub-encoding plates are still required for imaging, while the number of sub-encoding plates required in the Hadamard scheme is still as high as 205, which is 6.5 times that required by the rotational measurement scheme. Thus, it can be seen that under the condition of undersampling, the novel single-pixel imaging scheme using rotational measurement not only requires fewer sub-encoding plates but also can ensure high imaging quality.

[0139] In this embodiment, the system matrix corresponding to the rotation measurement calculated by using the Geant4 software to simulate data and the proposed beam model realizes high-quality single-pixel radiation imaging under rotation measurement with a very small number of coding plates. The imaging quality PSNR is as high as 37.8 under full sampling. Subsequently, relevant undersampling experiments were carried out. When the sampling rate is 20%, the decrease in imaging quality cannot be intuitively felt, and the image PSNR slightly decreases to 32.6 but far exceeds the Hadamard imaging effect under the same conditions. The proposed imaging method under this new measurement form can greatly reduce the demand of the imaging system for the number of sub-coding plates, simplify the manufacturing and operation difficulties of relevant modulation devices, and will contribute to the development of single-pixel radiation imaging technology.

[0140] The above-described embodiments are only preferred embodiments given to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A single-pixel radiation imaging method based on rotational measurement, characterized in that: It includes the following steps: Determine the boundary lines of the beam region; Traverse and calculate the areas of the pixels of the object passed through by the beam region at different angles along the upper and lower boundary lines; Obtain the ray field after the sub-coded plate is rotationally modulated at a preset angle; Use the ray fields of all sub-coded plates to obtain the system matrix; Perform reconstruction and restoration using the reconstruction algorithm and the system matrix; The beam region and the boundary lines are calculated in the following manner: Divide the image region into several pixel grid regions; Calculate the upper boundary ray and the lower boundary ray respectively according to the beam boundary equation; Determine the beam region according to the upper boundary ray and the lower boundary ray; The areas of the pixels passed through by the upper boundary ray and the lower boundary ray are calculated respectively according to the intersection situation of the beam with the passed pixels, specifically including the following four situations: The first situation: Lower boundary: Upper boundary: The second situation: Lower boundary: Upper boundary: The third situation: Lower boundary: Upper boundary: The sixth situation: Lower boundary: Upper boundary: Among them, S △ , S □ represents the area of the overlapping part of the beam region and the pixel; The system matrix is updated in the following manner: Classify according to the situation of the pixels passed through between the upper and lower boundary rays; Traverse the pixel numbers passed through along the boundary line. For different passing situations of the upper and lower boundary rays, the area at the corresponding pixel position in the system matrix is updated according to the classification situation; The classification according to the situation of the pixels passed through between the upper and lower boundary rays specifically includes three situations: 1) The two rays pass through the same pixel, 2) They pass through two different pixels respectively and there are no pixels that are not passed through between the two different pixels, 3) They pass through two different pixels respectively and there are other pixels that are not passed through between the two different pixels; The area of the corresponding pixel in the system matrix is updated in the following manner: (1) The two rays pass through the same pixel grid; W i = W 1-i + W 2-i - δ 2 ; Among them, W i represents the modulation effect (area) on the i-th pixel; W 1-i represents the area of the lower boundary on the i-th pixel; W 2-i represents the area of the upper boundary on the i-th pixel; (2) They pass through two different pixels respectively and there are no pixels that are not passed through between the two different pixels. The modulation effect of the pixels that meet the conditions remains unchanged; (3) Passing through two different pixels respectively and there are other pixels between the two different pixels that have not been passed through, the spatial element modulation effect is recorded as W i =δ 2 ; Wherein, d1 represents the intercept of the upper boundary line on the pixel; d2 represents the intercept of the lower boundary line on the pixel; δ represents the side length of the unit pixel; m represents the slope of the current beam.

2. The single-pixel radiation imaging method based on rotational measurement according to claim 1, characterized in that: The sub-coded plate is designed in a preset manner and is used to partially block the rays incident on the sub-coded plate; so that the rays are modulated by each sub-coded plate to obtain a ray field with a beam-like distribution.

3. The single-pixel radiation imaging method based on rotational measurement according to claim 1, wherein: The sub-coded plate is a striped coded plate; regions allowing rays to pass through are provided in the striped coded plate.

4. The single-pixel radiation imaging method based on rotational measurement according to claim 1, wherein: The system matrix is calculated in the following manner: Traverse and calculate the areas of the pixels of the object passed through by the beam at different angles along the upper and lower boundary lines; Correct the areas of the pixels passed through by the rays according to the situation of the two boundary lines passing through the pixels; Use the ray fields of all sub-coded plates to obtain the system matrix; The system matrix P is used to record the modulation effects of all encoding plates. P i is used as a row of P to record the modulation effect after one rotation of a sub-encoding plate.

5. The single-pixel radiation imaging method based on rotational measurement according to claim 1, wherein: The boundary lines of the beam region are calculated in the following manner: Let the beam boundary equation be y = mx + b, and the longitudinal intercepts when it intersects a certain pixel are d1 and d2 successively, where the lower left vertex of the pixel is (x a ,y j ). Then the expressions for the two intercepts are: d1 = mx a + b - y j d2 = m(x a +δ)+b - y j Determine the ray situation and the passed pixel numbers according to d1 and d2; Wherein, b represents the intercept of the current ray on the vertical axis of the coordinate system.

6. A single-pixel radiation imaging system based on rotational measurement, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein, When the processor executes the program, it implements the method described in any one of claims 1 to 5 above.

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