Method and device for detecting light transmission performance of anti-scatter grids and method for grouping anti-scatter grids

Abstract

The invention provides a light transmission performance detection method and device for an anti-scatter grating. The method comprises the following steps: acquiring each first light transmission image; respectively extracting each first grating luminous flux from each first light passing image to obtain the maximum first grating luminous flux; obtaining a first stepping position corresponding to the maximum first grid body luminous flux according to the corresponding relation between the first light passing image and the first stepping position so as to determine a first direction grid body focus coordinate; gradually moving the anti-scattering grid along a second direction from the grid body focus coordinate in the first direction to obtain each second light-passing image; and respectively extracting each second grid body luminous flux from each second light passing image to obtain the maximum second grid body luminous flux as the absolute luminous flux of the anti-scattering grid. According to the method and the device for detecting the light transmission performance of the anti-scattering grid, the absolute luminous flux and other light transmission performance parameters of the anti-scattering grid can be directly obtained, and the detection accuracy of the overall performance of the anti-scattering grid can be improved.

Description

Technical Field

[0001] The present application belongs to the technical field of medical equipment, and in particular relates to a method and device for detecting the light transmission performance of an anti-scatter grid and a method for grouping anti-scatter grids. Background Art

[0002] Anti-scatter grids absorb and filter the scattered X-rays that pass through the irradiated object during CT detection to ensure that only direct X-rays reach the detector, thereby improving the imaging clarity and contrast of the irradiated object and optimizing the imaging quality of the CT system.

[0003] As a key component in CT systems, anti-scatter grids (ASGs) require pre-shipment performance evaluation to identify potential issues and avoid degradation of CT system imaging quality due to performance deficiencies in the ASG during actual use. Existing techniques typically use two-dimensional measurement equipment to measure key structural parameters of the ASG, such as the grid aperture, wall, and surface quality. The performance of the ASG is evaluated by calculating the deviation between the measured and designed values ​​of these key structural parameters. However, this existing technique can only measure the mechanical dimensions of the ASG and cannot assess its light transmission performance. This performance directly impacts its ability to suppress X-ray scattering and refraction, significantly impacting CT system imaging quality. For example, X-ray scattering and refraction can increase background noise in CT images, reduce image contrast, and generate scattering artifacts. Therefore, existing ASG performance testing methods based on two-dimensional measurement equipment are unable to fully assess the ASG's overall performance, making it difficult to accurately assess its performance in actual applications.

[0004] Based on this, how to realize the detection of the light transmission performance of the anti-scatter grid and improve the detection accuracy of the overall performance of the anti-scatter grid is an important issue that needs to be solved urgently. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of this application is to provide a method for detecting the light transmission performance of an anti-scatter grating, which is used to solve the problems of the current anti-scatter grating performance detection method, such as the inability to detect the light transmission performance of the anti-scatter grating and the limited accuracy of detecting the overall performance of the anti-scatter grating.

[0006] To achieve the above-mentioned and other related objectives, the present invention provides a method for detecting the light transmission performance of an anti-scatter grid, comprising the following steps:

[0007] Starting from a preset starting position, the anti-scatter grid to be inspected is gradually moved along a first direction to obtain first light transmission images corresponding to each first step position; based on each first light transmission image, the light flux of each first grid body of the anti-scatter grid is respectively extracted; based on each first grid body light flux, the maximum first grid body light flux is obtained; based on the correspondence between the first light transmission image and the first step position, the first step position corresponding to the maximum first grid body light flux is obtained as the grid body focal coordinate in the first direction; starting from the grid body focal coordinate in the first direction, the anti-scatter grid is gradually moved along a second direction to obtain second light transmission images corresponding to each second step position; based on each second light transmission image, the light flux of each second grid body of the anti-scatter grid is respectively extracted; based on each second grid body light flux, the maximum second grid body light flux is obtained as the absolute light flux of the anti-scatter grid; wherein the first direction and the second direction are perpendicular to each other.

[0008] In one embodiment of the present invention, after obtaining the maximum second grating body light flux, the method further includes:

[0009] According to the correspondence between the second light transmission image and the second step position, the second step position corresponding to the maximum second grating light flux is obtained as the second direction grating focus coordinate of the anti-scatter grid; based on the first direction grating focus coordinate and the second direction grating focus coordinate, the grating focus coordinate of the anti-scatter grid is obtained.

[0010] In one embodiment of the present invention, a method for obtaining the maximum first grating body light flux and the maximum second grating body light flux includes:

[0011] According to the corresponding relationship between the first grating body luminous flux and the first step position, function fitting is performed on each of the first grating body luminous fluxes and each of the first step positions to obtain a first fitting function of the first grating body luminous flux varying with the first step position; the maximum value of the first fitting function is calculated as the maximum first grating body luminous flux; according to the corresponding relationship between the second grating body luminous flux and the second step position, the function fitting is performed on each of the second grating body luminous fluxes and each of the second step positions to obtain a second fitting function of the second grating body luminous flux varying with the second step position; the maximum value of the second fitting function is calculated as the maximum second grating body luminous flux.

[0012] In one embodiment of the present invention, the method for detecting light transmission performance of an anti-scatter grid further includes:

[0013] Based on each of the first light transmission images, a first grid hole light transmission image corresponding to each grid hole of the anti-scatter grid is obtained, and based on each of the second light transmission images, a second grid hole light transmission image corresponding to each grid hole is obtained; based on the first grid hole light transmission image corresponding to each grid hole, a first grid hole light flux corresponding to each grid hole is extracted, and based on the second grid hole light transmission image corresponding to each grid hole, a second grid hole light flux corresponding to each grid hole is extracted; based on the first grid hole light flux corresponding to each grid hole, a maximum first grid hole light flux of each grid hole is obtained, and based on the second grid hole light flux corresponding to each grid hole, a maximum first grid hole light flux of each grid hole is obtained. The method comprises the steps of: determining the first direction grid hole focus coordinates of each grid hole according to the first step position corresponding to each maximum first grid hole light flux, and determining the second direction grid hole focus coordinates of each grid hole according to the second step position corresponding to each maximum second grid hole light flux; using the corresponding first direction grid hole focus coordinates and second direction grid hole focus coordinates as the grid hole focus coordinates of the corresponding grid hole; and obtaining a focusing detection value of the anti-scatter grid based on each grid hole focus coordinate and according to a focusing calculation method.

[0014] In one embodiment of the present invention, the method for obtaining the focus detection value includes:

[0015] The first-direction grid aperture focus coordinates and the second-direction grid aperture focus coordinates belonging to the same grid aperture are used as the grid aperture focus coordinates of the corresponding grid aperture; the coordinate spacing between each of the grid aperture focus coordinates is calculated, and the maximum coordinate spacing is extracted from the coordinate spacings as the focusing detection value of the anti-scatter grid.

[0016] In one embodiment of the present invention, after obtaining the second light transmission image, the method further includes:

[0017] Based on each of the second light transmission images, a second grid hole light transmission image corresponding to each grid hole of the anti-scatter grid is obtained; based on the second grid hole luminous flux corresponding to each of the grid holes, a maximum second grid hole luminous flux of each of the grid holes is obtained as the grid hole absolute luminous flux of the corresponding grid hole; based on the absolute luminous flux of each of the grid holes, a uniformity detection value range of the anti-scatter grid is obtained according to a uniformity calculation method.

[0018] In one embodiment of the present invention, the method for obtaining the uniformity detection value range includes:

[0019] Calculating an average luminous flux of the absolute luminous fluxes of the grid holes of the anti-scatter grid; calculating, for each absolute luminous flux of the grid holes, a luminous flux difference between the absolute luminous flux of the grid holes and the average luminous flux; respectively calculating a ratio between each luminous flux difference and the average luminous flux; extracting a maximum positive ratio and a minimum negative ratio from each of the ratios as an upper limit and a lower limit, respectively, for uniformity detection of the anti-scatter grid, to obtain a uniformity detection value range of the anti-scatter grid.

[0020] Correspondingly, the present invention provides a method for grouping anti-scatter grids, comprising:

[0021] The above-mentioned anti-scatter grid light transmission performance detection method is used to obtain the absolute luminous flux of each anti-scatter grid; based on the absolute luminous flux of the grid, the anti-scatter grids are grouped according to a preset first grouping principle to obtain the anti-scatter grid groups.

[0022] Correspondingly, the present invention provides a device for detecting the light transmission performance of an anti-scatter grid, comprising:

[0023] Point light source, used to emit visible light;

[0024] a flat panel detector, configured to receive the visible light rays passing through the anti-scatter grid and form a corresponding light transmission image based on the visible light rays passing through the anti-scatter grid; the anti-scatter grid being placed on a light receiving surface of the flat panel detector; the light transmission image comprising a first light transmission image and a second light transmission image;

[0025] A mobile platform, used for placing the flat panel detector and moving in a direction corresponding to the control signal according to the control signal;

[0026] a processing module, connected to the flat panel detector and the mobile platform, respectively, for acquiring the light transmission image and step information of the mobile platform, and obtaining the absolute light flux of the anti-scatter grid using any of the above-mentioned light transmission performance detection methods for the anti-scatter grid; the step information includes a first step position and a second step position;

[0027] The distance between the point light source and the surface of the anti-scatter grid away from the point light source is equal to the focal length of the anti-scatter grid standard.

[0028] In one embodiment of the present invention, the device further includes: a light shield for shielding external visible light to form a dark detection environment; the point light source, the flat panel detector and the moving platform are all located inside the light shield.

[0029] As described above, the method for detecting the light transmission performance of an anti-scatter grid provided in this application has at least the following beneficial effects:

[0030] The method includes acquiring first light transmission images of an anti-scatter grid to be inspected in a first direction; extracting the light flux of each first grid body of the anti-scatter grid to be inspected based on each of the first light transmission images to obtain a maximum first grid body light flux; obtaining the coordinates of the grid body focus of the anti-scatter grid to be inspected in the first direction based on the coordinates of the maximum first grid body light flux in the first direction; gradually moving the anti-scatter grid to be inspected along a second direction starting from the coordinates of the grid body focus in the first direction to obtain second light transmission images of the anti-scatter grid to be inspected; obtaining the light flux of each second grid body of the anti-scatter grid to be inspected based on each of the second light transmission images; and obtaining the maximum second grid body light flux based on each of the second grid body light fluxes as the absolute grid body light flux of the anti-scatter grid to be inspected. The method can directly detect the light transmission performance of the anti-scatter grid to be inspected and obtain light transmission performance parameters such as the absolute light flux of the anti-scatter grid to directly determine the suppression effect of the anti-scatter grid to be inspected on scattered X-rays, thereby improving the accuracy of detecting the overall performance of the anti-scatter grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 FIG2 is a flow chart of a first embodiment of a method for detecting light transmission performance of an anti-scatter grid provided by the present application.

[0032] Figure 2 FIG2 is a flow chart of a second embodiment of a method for detecting light transmission performance of an anti-scatter grid provided in the present application.

[0033] Figure 3 FIG2 is a flow chart of a third embodiment of the method for detecting the light transmission performance of the anti-scatter grid provided in the present application.

[0034] Figure 4 FIG2 is a flow chart of an anti-scatter grid grouping method provided by the present application in one embodiment.

[0035] Figure 5 FIG2 is a flow chart of another embodiment of the anti-scatter grid grouping method provided by the present application.

[0036] Figure 6 FIG2 is a schematic structural diagram of a device for detecting light transmission performance of an anti-scatter grid provided in the present application in one embodiment.

[0037] Figure 7 FIG2 is a schematic structural diagram of another embodiment of the device for detecting the light transmission performance of the anti-scatter grid provided in the present application.

[0038] Description of Reference Numerals

[0039] S1 to S11, steps; S5' to S7', steps; A, anti-scatter grid; 1, point light source; 2, flat panel detector; 3, mobile platform; 4, processing module; 5, light shield. DETAILED DESCRIPTION

[0040] The following describes the embodiments of the present application through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other unless they conflict.

[0041] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. Therefore, the illustrations only show components related to the present application and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0042] To facilitate understanding of the technical solutions provided by this application, the relevant terms in this application are explained before the specific embodiments, as follows:

[0043] Asymmetric extended rational function: It is a special form of extension of rational function in function approximation theory.

[0044] Absolute luminous flux refers to the total amount of light energy that passes through the anti-scatter grid under specific conditions. It directly affects the imaging quality and effect, and is an important parameter for measuring the light transmission performance of the anti-scatter grid. For example, the higher the absolute luminous flux, the more light energy passes through the anti-scatter grid, which helps to improve the signal-to-noise ratio of the imaging. Conversely, too low an absolute luminous flux will lead to a decline in imaging quality, resulting in dim or blurred images.

[0045] Focusing: refers to the degree of convergence of the anti-scatter grid's focus.

[0046] Uniformity: refers to the consistency of X-ray transmittance in different areas of the anti-scatter grid.

[0047] The following embodiments of the present application are described in detail with reference to the accompanying drawings. In the absence of conflict, the features of the following embodiments and implementations can be combined with each other.

[0048] The following embodiment of the present application provides a method for testing the light transmission performance of an anti-scatter grid, comprising: obtaining first light transmission images of the anti-scatter grid to be tested in a first direction; extracting the light flux of each first grid body of the anti-scatter grid to be tested based on each first light transmission image to obtain a maximum first grid body light flux; obtaining the coordinates of the grid body focus of the anti-scatter grid to be tested in the first direction according to the coordinates of the maximum first grid body light flux corresponding to the first direction; and gradually moving the anti-scatter grid to be tested along a second direction starting from the grid body focus coordinates in the first direction to obtain the coordinates of the anti-scatter grid to be tested. each second light transmission image; based on each second light transmission image, obtaining each second grating body luminous flux of the anti-scatter grating to be tested; based on each second grating body luminous flux, obtaining the maximum second grating body luminous flux as the grating body absolute luminous flux of the anti-scatter grating to be tested. The method can directly test the light transmission performance of the anti-scatter grating to be tested and obtain light transmission performance parameters such as the absolute luminous flux of the anti-scatter grating to be tested, so as to directly obtain the suppression effect of the anti-scatter grating to be tested on scattered X-rays based on the light transmission performance parameters, thereby helping to improve the detection accuracy of the overall performance of the anti-scatter grating.

[0049] See also Figure 1 , which is a schematic flow chart of a method for detecting light transmission performance of an anti-scatter grid provided by the present invention in a first embodiment.

[0050] like Figure 1 As shown, in this embodiment, the light transmission performance detection method of the anti-scatter grating provided by the present invention is applicable to a two-dimensional anti-scatter grating, and the light transmission performance detection method of the anti-scatter grating includes the following steps:

[0051] Step S1: Starting from a preset starting position, gradually moving the anti-scatter grid to be inspected along a first direction to obtain first light transmission images of the anti-scatter grid corresponding to each first step position; and extracting the light flux of each first grid body of the anti-scatter grid based on each first light transmission image;

[0052] The first light transmission image includes images corresponding to each first step position formed on the flat panel detector when the anti-scatter grid is gradually moved along the first direction under the illumination of a preset point light source; the first step position is the movement position of the anti-scatter grid in the first direction;

[0053] The distance between the preset point light source and the surface of the anti-scatter grid away from the preset point light source is equal to the focal length of the anti-scatter grid;

[0054] The preset starting position is a position where the center of the preset point light source coincides with the focus of the anti-scatter grid standard;

[0055] The first grating light flux is the grating light flux at each first step position of the anti-scatter grid in the first direction; the grating light flux is the sum of the light fluxes of each grating hole of the anti-scatter grid; and the light flux of a single grating hole is the sum of the pixel grayscale values ​​of the image area corresponding to a single grating hole in the anti-scatter grid to be detected.

[0056] Specifically, under the illumination of the preset point light source, starting from a preset starting position, the anti-scatter grid is gradually moved along the first direction according to a preset step length. When the total length of the step along the first direction reaches the preset total length of the step, a first light transmission image formed on the flat panel detector by the anti-scatter grid at each first step position is obtained; based on each first light transmission image, the grid body light flux of the anti-scatter grid at each first step position is calculated as the first grid body light flux.

[0057] Optionally, the method for detecting the light transmission performance of the anti-scatter grid comprises obtaining a plurality of first initial light transmission images at each of the first step positions. After obtaining the first initial light transmission images, the method for acquiring the first light transmission images further comprises:

[0058] Perform image filtering on each of the first initial light transmission images to obtain the filtered first initial light transmission image; perform pixel averaging on the first initial light transmission image after filtering at each of the first step positions to obtain the pixel averaged light transmission image as the first light transmission image.

[0059] Optionally, the implementation of performing image screening on each of the first initial light-transmitting images includes:

[0060] According to the preset light source requirement, the first initial light transmission images whose corresponding point light sources meet the preset light source requirement are screened out from each first initial light transmission image as the screened first initial light transmission image.

[0061] Optionally, the preset light source requirement includes: the light intensity of the point light source is within a preset light intensity range and / or the light field uniformity of the point light source meets a preset light field uniformity requirement.

[0062] Exemplarily, the preset light intensity range includes: 29000LSB to 31000LSB.

[0063] Optionally, the method for detecting whether the light field uniformity of the point light source meets a preset light field uniformity requirement includes:

[0064] Obtaining a light source image corresponding to each of the first initial light transmission images; dividing the light source image into image regions, obtaining a mean grayscale value of pixels corresponding to each of the image regions; calculating a difference between the mean grayscale values ​​of pixels; and detecting whether each of the differences is less than a preset difference threshold. If so, determining that the light field uniformity of the point light source meets a preset light field uniformity requirement.

[0065] The light source image is an image formed by an empty field area of ​​the flat panel detector; the empty field area is an area on the flat panel detector that is not blocked by the anti-scatter grid to be detected.

[0066] Optionally, the pixel averaging may be implemented by:

[0067] Obtaining each filtered transparent image corresponding to the current step position as each current image to be averaged; extracting the grayscale value of each pixel in each current image to be averaged; calculating the grayscale value mean corresponding to each pixel position based on the grayscale value of each pixel in each current image to be averaged, which is the ratio of the sum of the grayscale values ​​of each pixel corresponding to the corresponding pixel position to the total number of the current images to be averaged; using each grayscale value mean as the grayscale value of the pixel at the corresponding pixel position to obtain the pixel-averaged image;

[0068] Wherein, the current step position includes: the first step position; the filtered light-transmitting image includes: the filtered first initial light-transmitting image;

[0069] In this embodiment, the image filtering is performed on the first initial transmission image to filter out transmission images affected by light source fluctuations, thereby avoiding measurement errors in the transmission performance of the anti-scatter grid due to light source fluctuations; and the pixel averaging is performed on the filtered transmission images at each of the first step positions to reduce image quantum noise, improve the image signal-to-noise ratio, and further reduce the impact of light source fluctuations on the measurement of the transmission performance of the anti-scatter grid.

[0070] Optionally, after calculating the grating body luminous flux of the anti-scatter grid at each of the first step positions, the method for obtaining the first grating body luminous flux further includes:

[0071] Obtaining the light response value of the flat panel detector at each of the first step positions; calculating a first ratio of the grating light flux at each of the first step positions to the light response value at the corresponding position; and calculating the product of the first ratio and a target reference value as the first grating light flux.

[0072] Exemplarily, the target reference value is 30000 LSB.

[0073] Optionally, the preset point light source includes: a visible light point light source.

[0074] Exemplarily, the visible light point light source includes: an LED point light source.

[0075] Optionally, the flat panel detector includes: a small pixel flat panel detector with a pixel size not greater than 50 μm×50 μm, so as to improve the accuracy of detecting the light transmission performance of the anti-scatter grid.

[0076] Exemplarily, the small-pixel flat panel detector includes: a CMOS flat panel detector.

[0077] It should be noted that in actual applications, the light intensity and environmental conditions may change dynamically. Therefore, the grayscale threshold of the flat panel detector can be set to a dynamic grayscale threshold so that the grayscale threshold of the flat panel detector can change dynamically with the light intensity and environmental conditions to adapt to different imaging conditions and lighting environments.

[0078] Exemplarily, the models of the CMOS flat panel detector include: NDT0506P.

[0079] Exemplarily, the preset step length is 1.5 mm.

[0080] Exemplarily, the preset total step length is 18 mm.

[0081] Step S2: obtaining a maximum first grating body luminous flux based on each of the first grating body luminous fluxes; obtaining a first step position corresponding to the maximum first grating body luminous flux based on a correspondence between the first light transmission image and the first step position; and determining a first-direction grating body focal coordinate of the anti-scatter grid based on the first step position corresponding to the maximum first grating body luminous flux;

[0082] Specifically, among the first grating body luminous fluxes, the first grating body luminous flux with the largest value is extracted as the maximum first grating body luminous flux; according to the correspondence between the first light transmission image and the first step position, combined with the correspondence between the first light transmission image and the first grating body luminous flux, the first step position corresponding to the maximum first grating body luminous flux is obtained; the coordinates of the first step position corresponding to the maximum first grating body luminous flux in the first direction are used as the first direction grating body focus coordinates of the anti-scatter grid.

[0083] Optionally, the step of obtaining a maximum first grating body luminous flux based on the luminous fluxes of the first grating bodies further includes:

[0084] According to the corresponding relationship between the first grating body luminous flux and the first step position, function fitting is performed on each of the first grating body luminous fluxes and each of the first step positions to obtain a first fitting function in which the first grating body luminous flux changes with the first step position; and the maximum value of the first fitting function is calculated as the maximum first grating body luminous flux.

[0085] Optionally, the function fitting is implemented by taking the first step position as the independent variable, taking the first grating luminous flux as the dependent variable, and using an asymmetric extended rational function to fit each first grating luminous flux and each first step position.

[0086] Exemplarily, the first fitting function is as follows:

[0087]

[0088] In the above formula, F(x) represents the first fitting function, whose value is the first grating body light flux; x represents the first step position; a represents the amplitude; (x≤b) and (x>b) represent conditional expressions for distinguishing the value of the first step position relative to b; C L and C R They respectively represent the first scaling factor, which is the scaling factor when the first step position is not greater than b, and the second scaling factor, which is the scaling factor when the first step position is greater than b. The first scaling factor and the second scaling factor are used to adjust the asymmetry of the function; α represents the exponential value, which affects the steepness of the function curve.

[0089] It should be noted that, considering that some anti-scatter grid samples are not bilaterally symmetrical (for example, the TJ sample is asymmetrical and has a deviation angle of 0.22°), the grating luminous flux distribution of the anti-scatter grid on both sides of the grid focal coordinate will be different. Therefore, an asymmetric extended rational function is used in this application to accurately fit the grating luminous flux of the anti-scatter grid at different step positions by adjusting the function parameters.

[0090] Step S3, starting from the focal coordinate of the anti-scatter grid in the first direction, gradually moving the anti-scatter grid along the second direction to obtain second light transmission images of the anti-scatter grid corresponding to each second step position; and extracting the light flux of each second grid body of the anti-scatter grid in the second direction based on each second light transmission image;

[0091] The second direction is perpendicular to the first direction.

[0092] The second light transmission image includes an image corresponding to each second step position formed on the flat panel detector when the anti-scatter grid is gradually moved along the second direction under the illumination of a preset point light source; the second step position is the movement position of the anti-scatter grid in the second direction;

[0093] The second grating light flux is the grating light flux at each second step position of the anti-scattering grid in the second direction.

[0094] Specifically, under the illumination of the preset point light source, the anti-scatter grid is gradually moved along the second direction according to the preset step length, starting from the grid focal coordinates in the first direction. When the total step length along the second direction reaches the preset total step length, a second light transmission image formed on the flat panel detector by the anti-scatter grid at each second step position is obtained. Based on each second light transmission image, the grid luminous flux of the anti-scatter grid at each second step position in the second direction is calculated as the second grid luminous flux.

[0095] Optionally, the method for detecting the light transmission performance of the anti-scatter grid comprises obtaining a plurality of second initial light transmission images at each second step position, and after obtaining the second initial light transmission images, obtaining the second light transmission images further comprises:

[0096] The image filtering is performed on the second initial transparent image to obtain the filtered second initial transparent image; the pixel averaging is performed on the filtered second initial transparent image at each second step position to obtain the pixel averaged transparent image as the second transparent image.

[0097] Optionally, after calculating the grating body light flux of the anti-scatter grid at each second step position, the method for obtaining the second grating body light flux further includes:

[0098] Obtaining the light response value of the flat panel detector at each second step position; calculating a second ratio of the grating body light flux at each second step position to the light response value at the corresponding position; and calculating the product of the second ratio and the target reference value as the second grating body light flux.

[0099] Step S4: based on the luminous fluxes of the second grating bodies, obtaining a maximum luminous flux of the second grating body as the absolute luminous flux of the anti-scatter grid;

[0100] Specifically, among the second grating body luminous fluxes, the second grating body luminous flux with the largest value is extracted as the maximum second grating body luminous flux; and the maximum second grating body luminous flux is used as the absolute luminous flux of the anti-scatter grid.

[0101] Optionally, the step of obtaining a maximum second grating body luminous flux based on the luminous fluxes of the second grating bodies further includes:

[0102] According to the corresponding relationship between the second grating body luminous flux and the second step position, the function fitting is performed on each second grating body luminous flux and each second step position to obtain a second fitting function in which the second grating body luminous flux changes with the second step position; and the maximum value of the second fitting function is calculated as the maximum second grating body luminous flux.

[0103] Optionally, after obtaining the maximum second grating body luminous flux, the method for detecting the light transmission performance of the anti-scatter grating further includes:

[0104] According to the correspondence between the second light transmission image and the second step position, combined with the correspondence between the second light transmission image and the second grating light flux, the second step position corresponding to the maximum second grating light flux is obtained; based on the second step position corresponding to the maximum second grating light flux, the second-direction grating focus coordinates are determined; based on the first-direction grating focus coordinates and the second-direction grating focus coordinates, the grating focus coordinates of the anti-scatter grid are obtained, so that the anti-scatter grid is calibrated and adjusted based on the grating focus coordinates to accurately align it with the X-ray source, ensuring that it is in an optimal working state, thereby more effectively blocking scattered photons and making the image clearer.

[0105] Optionally, determining the second-direction grating body focus coordinates based on the second step position corresponding to the maximum second grating body light flux includes: taking the coordinates of the second step position corresponding to the maximum second grating body light flux in the second direction as the second-direction grating body focus coordinates.

[0106] It should be noted that the focus of the anti-scatter grid refers to the position corresponding to the point where the grid of the anti-scatter grid converges in reverse, wherein the degree of convergence of the focus of the anti-scatter grid determines the selectivity performance of the anti-scatter grid for scattering and direct radiation of a point X-ray light source after passing through an object.

[0107] Optionally, a method for obtaining the absolute luminous flux of the anti-scatter grid includes:

[0108] σ A =I(x f ,y f )

[0109] In the above formula, σ A represents the absolute luminous flux of the grating; x f represents the focal coordinate of the first direction grid body; f represents the focal coordinate of the second direction grid body; I(x f ,y f) represents the maximum second grating luminous flux, that is, the grating luminous flux of the anti-scattering grid at the grating focal coordinate.

[0110] Optionally, during the actual measurement process, the method for obtaining the absolute luminous flux of the anti-scatter grid further includes:

[0111]

[0112] In the above formula, σ A Represents the absolute luminous flux of the grating; I(x f ,y d ) indicates that the anti-scatter grid is at (x f ,y d ) at the second grating body luminous flux; x f represents the focal coordinate of the first direction grid body; f represents the focal coordinate of the second direction grid body; d Indicates the actual second direction grid focus coordinates during the actual measurement process (taking into account the influence of the step length error during the actual measurement process); c2 represents the proportional constant used to adjust y d with y f The difference between the two has an impact on the absolute luminous flux of the grating; α2 represents the index used to control y d and y f The degree of influence of the difference between them on the absolute luminous flux of the grid body.

[0113] The above embodiment provides a method for testing the light transmission performance of an anti-scatter grid, which comprises obtaining first light transmission images of the anti-scatter grid to be tested in a first direction; extracting the light flux of each first grid body of the anti-scatter grid to be tested based on each first light transmission image to obtain a maximum first grid body light flux; obtaining the coordinates of the grid body focus of the anti-scatter grid to be tested in the first direction according to the coordinates of the maximum first grid body light flux corresponding to the first direction; and gradually moving the anti-scatter grid to be tested along a second direction starting from the coordinates of the grid body focus of the first direction to obtain the coordinates of the anti-scatter grid to be tested. each second light transmission image; based on each second light transmission image, obtaining each second grating body luminous flux of the anti-scatter grating to be tested; based on each second grating body luminous flux, obtaining the maximum second grating body luminous flux as the grating body absolute luminous flux of the anti-scatter grating to be tested. The method can directly test the light transmission performance of the anti-scatter grating to be tested and obtain light transmission performance parameters such as the absolute luminous flux of the anti-scatter grating to be tested, so as to directly obtain the suppression effect of the anti-scatter grating to be tested on scattered X-rays based on the light transmission performance parameters, thereby helping to improve the detection accuracy of the overall performance of the anti-scatter grating.

[0114] See also Figure 2, which is a schematic flow chart of a second embodiment of a method for detecting light transmission performance of an anti-scatter grid provided by the present invention;

[0115] like Figure 2 As shown, the light transmission performance detection method of the anti-scatter grid provided by the present invention, after obtaining the first light transmission image and the second light transmission image, the light transmission performance detection method of the anti-scatter grid further includes:

[0116] Step S5: performing image segmentation on each of the first light transmission images to obtain a first light transmission image corresponding to each aperture of the anti-scatter grid; and performing image segmentation on each of the second light transmission images to obtain a second light transmission image corresponding to each aperture of the anti-scatter grid;

[0117] Specifically, a first grayscale threshold corresponding to the first transparent image is obtained; based on the first grayscale threshold, image segmentation is performed on the first transparent image to obtain first high-grayscale images that are higher than the first grayscale threshold; each of the first high-grayscale images is used as the first grid hole transparent image of the corresponding grid hole; and a second grayscale threshold corresponding to the second transparent image is obtained; based on the second grayscale threshold, image segmentation is performed on the second transparent image to obtain second high-grayscale images that are higher than the second grayscale threshold; each of the second high-grayscale images is used as the second grid hole transparent image of the corresponding grid hole.

[0118] The first grayscale threshold and the second grayscale threshold are grayscale thresholds set by the flat panel detector according to the light intensity. That is, the grayscale threshold of the flat panel detector is set as a dynamic grayscale threshold. By dynamically adjusting the grayscale threshold of the flat panel detector, key features in the image, such as the grid holes and grid walls of the anti-scatter grid, can be more accurately identified and distinguished under different lighting conditions.

[0119] Optionally, other existing image segmentation methods may be used to perform image segmentation on each of the first light transmission images or the second light transmission images to obtain a grating aperture light transmission image corresponding to each of the grating apertures, which is not limited in this application.

[0120] Step S6, extracting the first grid hole luminous flux corresponding to each grid hole based on the first grid hole light transmission image corresponding to each grid hole; and extracting the second grid hole luminous flux corresponding to each grid hole based on the second grid hole light transmission image corresponding to each grid hole;

[0121] Specifically, for each of the grid holes, based on each of the first grid hole light transmission images corresponding to the grid hole, each grid hole light flux of the grid hole in the first direction is calculated respectively, and the first grid hole light flux of the grid hole is calculated as the sum of the pixel grayscale values ​​of the first grid hole light transmission images; and based on each of the second grid hole light transmission images corresponding to the grid hole, each grid hole light flux of the grid hole in the second direction is calculated respectively, and the second grid hole light flux of the grid hole is calculated as the sum of the pixel grayscale values ​​of the second grid hole light transmission images.

[0122] Step S7: obtaining the maximum first grid hole luminous flux of each grid hole based on the first grid hole luminous flux corresponding to each grid hole; and obtaining the maximum second grid hole luminous flux of each grid hole based on the second grid hole luminous flux corresponding to each grid hole;

[0123] Specifically, for each of the grid holes, among the first grid hole luminous fluxes corresponding to the grid holes, the first grid hole luminous flux with the largest value is extracted as the maximum first grid hole luminous flux; among the second grid hole luminous fluxes corresponding to the grid holes, the second grid hole luminous flux with the largest value is extracted as the maximum second grid hole luminous flux.

[0124] Optionally, the method further comprises: obtaining the maximum first grid hole luminous flux of each grid hole based on the first grid hole luminous flux corresponding to each grid hole, and obtaining the maximum first grid hole luminous flux of the grid hole based on the first grid hole luminous flux corresponding to a single grid hole.

[0125] According to the correspondence between the maximum first grating hole luminous flux and the first step position, the function fitting is performed on each of the first grating hole luminous fluxes and the first step position to obtain a third fitting function in which the first grating hole luminous flux changes with the first step position; and the maximum value of the third fitting function is calculated as the maximum first grating hole luminous flux.

[0126] It should be noted that the method for obtaining the maximum second grid hole luminous flux is the same as the method for obtaining the maximum first grid hole luminous flux, which will not be described in detail here.

[0127] Step S8, determining the first grid focus coordinates of each grid hole according to the first step position corresponding to each maximum first grid hole light flux; and determining the second direction grid focus coordinates of each grid hole according to the second step position corresponding to each maximum second grid hole light flux;

[0128] Specifically, based on the correspondence between the first aperture light transmission image and the first step position, combined with the correspondence between the first aperture light transmission image and the first aperture light flux, the coordinates of the first step position corresponding to each of the maximum first aperture light fluxes in the first direction are obtained as the aperture focus coordinates of the aperture in the first direction;

[0129] According to the correspondence between the second aperture light transmission image and the second step position, combined with the correspondence between the second aperture light transmission image and the second aperture luminous flux, the coordinates of the second step position corresponding to each of the maximum second aperture luminous fluxes in the second direction are obtained as the coordinates of the aperture focus in the second direction of the aperture.

[0130] Step S9: Using the corresponding first-direction grid aperture focus coordinates and the second-direction grid aperture focus coordinates as the grid aperture focus coordinates of the grid aperture; and obtaining a focusing detection value of the anti-scatter grid based on the grid aperture focus coordinates and a focusing calculation method.

[0131] Specifically, the first-direction grid aperture focus coordinates and the second-direction grid aperture focus coordinates belonging to the same grid aperture are used as the grid aperture focus coordinates of the corresponding grid aperture; the coordinate spacings between the grid aperture focus coordinates are calculated, and the maximum coordinate spacing is extracted from the coordinate spacings as the focusing detection value of the anti-scatter grid.

[0132] Optionally, after obtaining the focusing detection value, the method further includes: performing focusing detection on the anti-scatter grid based on a focusing standard value and the focusing detection value to obtain a focusing detection result of the anti-scatter grid.

[0133] Optionally, the implementation method of the focusing detection includes: judging whether the focusing detection value is less than the focusing standard value; if so, determining that the focusing of the anti-scatter grid meets the focusing requirement.

[0134] Optionally, the focusing standard value is set according to the focal spot size or imaging effect of the X-ray source.

[0135] Exemplarily, the focusing standard value is 0.6 mm.

[0136] It should be noted that obtaining accurate grid focal coordinates can ensure that X-rays are correctly aligned with the anti-scatter grid based on the accurate grid focal coordinates, thereby maximizing the anti-scatter grid's suppression effect on scattered X-rays and improving image quality.

[0137] The above embodiment provides a method for detecting the light transmission performance of an anti-scatter grid, which obtains a first grid hole light transmission image and a second grid hole light transmission image corresponding to each grid hole; extracts the first grid hole light flux and the second grid hole light flux corresponding to each grid hole based on the first grid hole light flux and the second grid hole light flux; obtains the maximum first grid hole light flux and the maximum second grid hole light flux of each grid hole based on the first grid hole light flux and the second grid hole light flux; determines the first grid hole focal length of each grid hole according to the first step position corresponding to each maximum first grid hole light flux; point coordinates; and determining the second grid hole focus coordinates of each grid hole according to the second step position corresponding to each of the maximum second grid hole light fluxes, and obtaining the grid hole focus coordinates of each grid hole based on the corresponding first grid hole focus coordinates and the second grid hole focus coordinates; based on each of the grid hole focus coordinates, obtaining a focusing detection value of the anti-scatter grid according to a focusing calculation method, wherein the method can directly obtain the focusing detection value of the anti-scatter grid, so as to detect the degree of convergence of the anti-scatter grid focus based on the focusing detection value, so as to ensure imaging uniformity and clarity of the CT system.

[0138] See also Figure 3 , which is a schematic flow chart of a method for detecting light transmission performance of an anti-scatter grid provided by the present invention in a third embodiment;

[0139] like Figure 3 As shown, the method for detecting the light transmission performance of the anti-scatter grid provided by the present invention, after obtaining the second light transmission image, the method for detecting the light transmission performance of the anti-scatter grid further includes:

[0140] Step S5′, performing image segmentation on each of the second light transmission images to obtain a second grid hole light transmission image corresponding to each grid hole of the anti-scatter grid;

[0141] Step S6′, based on the second grid hole luminous flux corresponding to each grid hole, respectively obtaining the maximum second grid hole luminous flux of each grid hole as the grid hole absolute luminous flux of the corresponding grid hole;

[0142] Specifically, for each of the grid holes, among the second grid hole luminous fluxes corresponding to the grid holes, the second grid hole luminous flux with the largest value is extracted as the maximum second grid hole luminous flux of the grid hole; and the maximum second grid hole luminous flux is used as the absolute grid hole luminous flux of the grid hole.

[0143] Step S7 ′: obtaining a uniformity detection value range of the anti-scatter grid based on the absolute luminous flux of each grid hole and a uniformity calculation method.

[0144] Specifically, the average luminous flux of the absolute luminous flux of the grid holes of the anti-scatter grid is calculated; for the absolute luminous flux of each grid hole, the luminous flux difference between the absolute luminous flux of the grid hole and the average luminous flux is calculated; the ratio of each luminous flux difference to the average luminous flux is calculated respectively, and among the ratios, the maximum positive ratio and the minimum negative ratio are extracted as the upper limit value and the lower limit value of the uniformity detection of the anti-scatter grid, respectively, to obtain the uniformity detection value range of the anti-scatter grid.

[0145] Optionally, after obtaining the uniformity detection value range, the method further includes: performing a uniformity detection on the anti-scatter grid based on the uniformity standard value range and the uniformity detection value range to obtain a uniformity detection result of the anti-scatter grid.

[0146] Optionally, the implementation of the uniformity detection includes: determining whether the uniformity detection value range is within the uniformity standard value range; if so, determining that the uniformity of the anti-scatter grid meets the uniformity requirement.

[0147] Optionally, the uniformity standard value range is set according to X-ray imaging effects.

[0148] Optionally, after obtaining the uniformity detection upper limit value and the uniformity detection lower limit value of the anti-scatter grid, the method further includes: performing percentage conversion on the uniformity detection upper limit value and the uniformity detection lower limit value, and obtaining the uniformity detection value range of the anti-scatter grid based on the uniformity detection upper limit value and the uniformity detection lower limit value after the percentage conversion.

[0149] Exemplarily, the uniformity standard value range is -10‰ to 10‰.

[0150] Optionally, after obtaining the ratio between each of the luminous flux differences and the luminous flux average value, the method for obtaining the uniformity detection value range further includes:

[0151] The ratios are converted into percentages to obtain percentage ratios. Among the percentage ratios, the largest positive percentage ratio and the smallest negative percentage ratio are extracted and used as the upper limit and lower limit of uniformity detection of the anti-scatter grid, respectively, to obtain a uniformity detection value range of the anti-scatter grid. In this embodiment, the deviation value of the absolute luminous flux of each grid hole of the anti-scatter grid can be obtained to achieve detection of the overall uniformity of the anti-scatter grid.

[0152] The above-mentioned embodiment provides a method for detecting the light transmission performance of an anti-scatter grid. By obtaining a uniformity detection value range of the anti-scatter grid based on the absolute light flux of each grid hole and a uniformity calculation method, the method can directly obtain the uniformity detection value range of the anti-scatter grid. This helps to detect whether the uniformity of the anti-scatter grid meets the uniformity requirement based on the uniformity standard value and the uniformity detection value range, thereby avoiding uneven attenuation of X-rays by the anti-scatter grid, which in turn affects the imaging clarity of the X-ray image.

[0153] See also Figure 4 , which is a schematic flow chart of an anti-scatter grid grouping method provided by the present invention in one embodiment;

[0154] like Figure 4 As shown, in this embodiment, the anti-scatter grid grouping method provided by the present invention, after adopting the light transmission performance detection method of the anti-scatter grid to obtain the absolute luminous flux of the grid body of each anti-scatter grid, the anti-scatter grid grouping method includes:

[0155] Step S10: grouping the anti-scatter grids based on the absolute luminous flux of the grid body and according to a preset first grouping principle to obtain anti-scatter grid groups;

[0156] Specifically, the absolute luminous flux difference between the two absolute luminous fluxes of the gratings is calculated; according to the preset luminous flux difference range of each group, the anti-scatter grids whose absolute luminous flux difference is within the corresponding preset luminous flux difference range are divided into a group to obtain each anti-scatter grid group.

[0157] Optional, such as Figure 5 As shown, after adopting the light transmission performance detection method of the anti-scatter grid to obtain the absolute light flux of the grid body and the focal coordinates of the grid body, the anti-scatter grid grouping method further includes:

[0158] Step S11 : grouping the anti-scatter grids based on the absolute luminous flux of the grid body and the coordinates of the grid body focal point according to a preset second grouping principle to obtain anti-scatter grid groups.

[0159] Specifically, the absolute luminous flux difference between the two absolute luminous fluxes of the gratings is calculated, and the grating focus coordinate difference between the two focal coordinates of the gratings is calculated; according to the preset luminous flux difference range and the preset focus coordinate difference range corresponding to each group, the anti-scatter grids whose absolute luminous flux and the grating focus coordinate difference are respectively located within the corresponding preset luminous flux difference range and the preset focus difference range are divided into a group to obtain each anti-scatter grid group.

[0160] It should be noted that in actual applications, an anti-scatter grid set containing multiple anti-scatter grids is usually required to be applied to a CT system. Therefore, it is necessary to reduce the focus offset and light flux difference between the anti-scatter grids in the same set to improve the imaging consistency of the CT system and help obtain higher image quality.

[0161] The above-mentioned embodiment provides a method for grouping anti-scatter grids. By adopting a method for detecting the light transmission performance of anti-scatter grids, light transmission performance parameters such as absolute light flux of each anti-scatter grid are obtained. Based on the light transmission performance parameters, the anti-scatter grids are grouped to obtain groups of anti-scatter grids with similar light transmission performance within the group. The anti-scatter grid grouping method facilitates more efficient utilization of qualified anti-scatter grids and avoids affecting the performance of the entire set of anti-scatter grids due to large performance differences among some anti-scatter grids. Furthermore, in actual applications, when an anti-scatter grid fails, the anti-scatter grid grouping method facilitates direct acquisition of a replacement anti-scatter grid from the same group of anti-scatter grids, thereby reducing the downtime of the CT system.

[0162] See also Figure 6 , showing a schematic structural diagram of a light transmission performance detection device of an anti-scatter grid provided by the present invention in one embodiment;

[0163] like Figure 6 As shown, in this embodiment, the light transmission performance detection device of the anti-scatter grid provided by the present invention includes:

[0164] Point light source 1, used to emit visible light:

[0165] a flat panel detector 2, configured to receive the visible light rays passing through the anti-scatter grid A to be detected, and to form a corresponding light transmission image based on the visible light rays passing through the anti-scatter grid; the anti-scatter grid A is placed in contact with the light receiving surface of the flat panel detector 2; the light transmission image includes a first light transmission image and a second light transmission image;

[0166] The mobile platform 3 is used to place the flat panel detector and translate in a direction corresponding to the control signal according to the preset step size according to the control signal;

[0167] a processing module 4, connected to the flat panel detector 2 and the mobile platform 3, respectively, for acquiring the light transmission image and step information of the mobile platform 3, and obtaining light transmission performance such as absolute light flux of the anti-scatter grid A using the light transmission performance detection method of the anti-scatter grid; the step information includes a first step position and a second step position;

[0168] The distance between the point light source 1 and the surface of the anti-scatter grid A away from the point light source is equal to the focal length of the anti-scatter grid standard; and there is a corresponding relationship between the light transmission image and the step information.

[0169] Specifically, the anti-scatter grid A is placed in contact with the light receiving surface of the flat-panel detector 2. In a dark detection environment, the point light source 1 is used to emit visible light. The mobile platform 3 gradually translates in a direction corresponding to the control signal according to the control signal. The flat-panel detector 2 receives the visible light passing through the anti-scatter grid and generates a light transmission image corresponding to each step position of the mobile platform 3. The processing module 4 obtains the light transmission image and the step information of the mobile platform 3, and adopts the light transmission performance detection method of the anti-scatter grid to obtain the light transmission performance of the anti-scatter grid A, such as the absolute luminous flux.

[0170] Optional, such as Figure 7 As shown, the light transmission performance detection device of the anti-scatter grid also includes: a light shield 5 for blocking external visible light to form a dark detection environment; the point light source 1, the flat panel detector 2 and the moving platform 3 are all located in the light shield 4.

[0171] Optionally, the control signal is issued by a preset program or an external control device. When the control signal is issued by the external control device, the mobile platform 3 is communicatively connected to the external control device.

[0172] The above-mentioned embodiment provides a device for testing the light transmission performance of an anti-scatter grid. The device comprises a point light source for emitting visible light, a flat-panel detector for receiving visible light that passes through the anti-scatter grid, and forming a corresponding light transmission image. A movable platform is provided for placing the flat-panel detector, and the movable platform is controlled by a control signal to translate in a corresponding direction so that the flat-panel detector forms a light transmission image at each step position. Furthermore, a processing module is provided, connected to the flat-panel detector and the movable platform, so that, based on each light transmission image and each step position, a light transmission performance testing method for the anti-scatter grid is used to obtain light transmission parameters such as the absolute light flux of the anti-scatter grid. The device can directly measure light transmission parameters such as the absolute light flux of the anti-scatter grid, thereby directly obtaining the anti-scatter grid's suppression effect on scattered X-rays, thereby improving the accuracy of testing the overall performance of the anti-scatter grid.

[0173] The embodiment of the present application also provides a computer-readable storage medium. A person of ordinary skill in the art will understand that all or part of the steps in the method for implementing the above embodiment can be completed by instructing the processor through a program, and the program can be stored in a computer-readable storage medium, and the storage medium is a non-transitory medium, such as a random access memory, a read-only memory, a flash memory, a hard disk, a solid-state hard disk, a magnetic tape, a floppy disk, an optical disc, and any combination thereof. The above storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that includes one or more available media. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a tape), an optical medium (for example, a digital video disc (DVD)), or a semiconductor medium (for example, a solid-state disk (SSD)), etc.

[0174] The embodiment of the present application may also provide a computer program product, the computer program product including one or more computer instructions. When the computer instructions are loaded and executed on a computing device, the process or function described in the embodiment of the present application is generated in whole or in part. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer or data center to another website, computer or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method.

[0175] When the computer program product is executed by a computer, the computer executes the method described in the above method embodiment. The computer program product can be a software installation package. When the above method is needed, the computer program product can be downloaded and executed on the computer.

[0176] The descriptions of the processes or structures corresponding to the above figures have different emphases. For parts that are not described in detail in a certain process or structure, please refer to the relevant descriptions of other processes or structures.

[0177] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by a person skilled in the art without departing from the spirit and technical concepts disclosed in this application shall be covered by the claims of this application.

Claims

1. A method for detecting the light transmission performance of an anti-scatter grid, characterized in that: include: Starting from a preset starting position, the anti-scatter grid to be inspected is moved stepwise along a first direction to obtain first light transmission images corresponding to each first step position; based on each first light transmission image, the light flux of each first grid body of the anti-scatter grid is extracted respectively; Based on the light fluxes of the first grating bodies, a maximum light flux of the first grating body is obtained; and according to the correspondence between the first light transmission image and the first step position, a first step position corresponding to the maximum light flux of the first grating body is obtained as the coordinate of the focus of the grating body in the first direction; Starting from the focal coordinate of the grid body in the first direction, the anti-scatter grid is gradually moved along the second direction to obtain second light transmission images corresponding to each second step position; based on each second light transmission image, the light flux of each second grid body of the anti-scatter grid is respectively extracted; Based on the luminous fluxes of the second grating bodies, a maximum luminous flux of the second grating body is obtained as the absolute luminous flux of the anti-scatter grid; The first direction and the second direction are perpendicular to each other.

2. The method according to claim 1, characterized in that At After obtaining the maximum second grating body luminous flux, the method further includes: According to the correspondence between the second light transmission image and the second step position, the second step position corresponding to the maximum second grating body light flux is obtained as the second direction grating body focus coordinate of the anti-scatter grid; The grid focus coordinates of the anti-scatter grid are obtained based on the grid focus coordinates in the first direction and the grid focus coordinates in the second direction.

3. The method according to claim 1, characterized in that The method for obtaining the maximum first grating body luminous flux and the maximum second grating body luminous flux includes: performing function fitting on each of the first grating body luminous fluxes and each of the first step positions according to the corresponding relationship between the first grating body luminous fluxes and the first step positions to obtain a first fitting function of the first grating body luminous flux varying with the first step position; and calculating a maximum value of the first fitting function as the maximum first grating body luminous flux; According to the corresponding relationship between the second grating body luminous flux and the second step position, the function fitting is performed on each second grating body luminous flux and each second step position to obtain a second fitting function in which the second grating body luminous flux changes with the second step position; and the maximum value of the second fitting function is calculated as the maximum second grating body luminous flux.

4. The method according to claim 1, wherein Also includes: Obtaining a first aperture transmission image corresponding to each aperture of the anti-scatter grid based on each of the first transmission images, and obtaining a second aperture transmission image corresponding to each of the apertures based on each of the second transmission images; Extracting the first grid hole luminous flux corresponding to each grid hole based on the first grid hole light transmission image corresponding to each grid hole, and extracting the second grid hole luminous flux corresponding to each grid hole based on the second grid hole light transmission image corresponding to each grid hole; Based on the first grid hole luminous flux corresponding to each of the grid holes, respectively obtain the maximum first grid hole luminous flux of each of the grid holes, and based on the second grid hole luminous flux corresponding to each of the grid holes, respectively obtain the maximum second grid hole luminous flux of each of the grid holes; Determining the first grid focus coordinates of each grid hole according to the first step position corresponding to each maximum first grid hole light flux, and determining the second direction grid focus coordinates of each grid hole according to the second step position corresponding to each maximum second grid hole light flux; Using the corresponding grid aperture focus coordinates in the first direction and the grid aperture focus coordinates in the second direction as the grid aperture focus coordinates of the corresponding grid aperture; Based on the focal coordinates of each grid hole and according to a focusing calculation method, a focusing detection value of the anti-scatter grid is obtained.

5. The method according to claim 4, characterized in that The method for obtaining the focusing detection value includes: The first-direction grid aperture focus coordinates and the second-direction grid aperture focus coordinates belonging to the same grid aperture are used as the grid aperture focus coordinates of the corresponding grid aperture; the coordinate spacing between each of the grid aperture focus coordinates is calculated, and the maximum coordinate spacing is extracted from the coordinate spacings as the focusing detection value of the anti-scatter grid.

6. The method according to claim 1, characterized in that After obtaining the second light transmission image, the method further includes: Based on each of the second light transmission images, obtaining a second grid hole light transmission image corresponding to each grid hole of the anti-scatter grid; Based on the second grid hole luminous flux corresponding to each grid hole, respectively obtaining the maximum second grid hole luminous flux of each grid hole as the grid hole absolute luminous flux of the corresponding grid hole; Based on the absolute luminous flux of each grid hole and according to a uniformity calculation method, a uniformity detection value range of the anti-scatter grid is obtained.

7. The method according to claim 6, characterized in that The method for obtaining the uniformity detection value range includes: Calculating an average luminous flux of the absolute luminous fluxes of the grid holes of the anti-scatter grid; calculating, for each absolute luminous flux of the grid holes, a luminous flux difference between the absolute luminous flux of the grid holes and the average luminous flux; respectively calculating a ratio between each luminous flux difference and the average luminous flux; extracting a maximum positive ratio and a minimum negative ratio from each of the ratios as an upper limit and a lower limit, respectively, for uniformity detection of the anti-scatter grid, to obtain a uniformity detection value range of the anti-scatter grid.

8. A method for grouping anti-scatter grids, characterized in that: include: The method for detecting the light transmission performance of the anti-scatter grid according to any one of claims 1 to 7 is used to obtain the absolute luminous flux of each anti-scatter grid; based on the absolute luminous flux of the grid, the anti-scatter grids are grouped according to a preset first grouping principle to obtain the anti-scatter grid groups.

9. A device for detecting light transmission performance of an anti-scatter grid, characterized in that: include: Point light source, used to emit visible light; a flat panel detector, configured to receive the visible light rays passing through the anti-scatter grid and form a corresponding light transmission image based on the visible light rays passing through the anti-scatter grid; the anti-scatter grid being placed on a light receiving surface of the flat panel detector; The clear light image includes a first clear light image and a second clear light image; A mobile platform, used for placing the flat panel detector and moving in a direction corresponding to the control signal according to the control signal; a processing module, connected to the flat panel detector and the mobile platform, respectively, for acquiring the light transmission image and step information of the mobile platform, and obtaining an absolute luminous flux of the anti-scatter grid using the light transmission performance detection method of the anti-scatter grid according to any one of claims 1 to 7; the step information including a first step position and a second step position; The distance between the point light source and the surface of the anti-scatter grid away from the point light source is equal to the focal length of the anti-scatter grid standard.

10. The device according to claim 9, characterized in that The device further comprises: a light shield for shielding external visible light to form a dark detection environment; the point light source, the flat panel detector and the moving platform are all located inside the light shield.

Images