Method for obtaining center projection image of detected object, readable storage medium and terminal

Abstract

The present invention provides a method for obtaining a central orthographic projection image of a detection object, the method comprising: using a ray source to continuously scan a number of detection targets in the detection object to collect cone beam projection data under multiple fields of view covering the orthographic projection directions of all detection targets; rearranging the data of each cone beam projection data to obtain parallel beam projection data at different angles; performing orthographic projection detection on each detection target based on each parallel beam projection data to obtain the orthographic projection data of each detection target; and obtaining a central orthographic projection image of the detection object based on the orthographic projection data of each detection target. The present invention solves the problem that the central orthographic projection image obtained by the existing method has a cone angle effect and cannot simultaneously obtain the orthographic projections of each detection target.

Description

Technical Field

[0001] The present invention relates to the technical field of image processing, and in particular to a method for obtaining a central orthographic projection image of a detection object, a readable storage medium and a terminal. Background Art

[0002] When a lithium battery is being charged, lithium ions need to enter the active particle position corresponding to the negative electrode from the positive electrode. If the negative electrode does not have a position to accept lithium ions, the lithium ions will precipitate on the surface of the negative electrode, forming dendrites, piercing the separator, causing a short circuit in the battery, and thus bringing the risk of thermal runaway of the battery. Therefore, in the design and production process of lithium batteries, the length and width of the negative electrode sheet must be greater than the length and width of the positive electrode sheet, and the part of the negative electrode sheet that is longer and wider than the positive electrode sheet is an overhang design. The relative position information of the positive and negative electrode sheets needs to be detected during the production process and after the stacking is completed. The existing detection methods can only be used to collect images through visible light during the stacking of the stacking machine to achieve detection. However, the position of the electrode sheet may shift after the stacking is completed and the separator is wrapped. Therefore, it is necessary to perform overhang detection on the positive and negative electrode sheets again after the stacking is completed and the separator is wrapped.

[0003] The commonly used method at present is to use X-ray imaging to obtain the information of the pole pieces inside the separator. However, due to the thicker battery layers, the smaller gaps between the pole pieces, and the cone beam X-rays used, only the pole pieces facing the radiation source can be seen clearly in the image obtained by X-raying the lithium battery, and the pole pieces on both sides of the image are gradually stacked, which affects the vertex position of the pole piece when using the algorithm to capture it, making it difficult to obtain the true relative position information of the positive and negative pole pieces. Summary of the invention

[0004] In view of the shortcomings of the prior art described above, an object of the present invention is to provide a method for obtaining an orthographic projection image of the center of a detection object, a readable storage medium and a terminal, so as to solve the problem that the orthographic projection image of the center of the detection object obtained by the existing method has a cone angle effect and cannot simultaneously obtain the orthographic projection of each detection target.

[0005] To achieve the above-mentioned object and other related objects, the present invention provides a method for obtaining a central orthographic projection image of a detection object, the method comprising:

[0006] Continuously scanning a number of detection targets in the detection object using a ray source to collect cone beam projection data in multiple fields of view covering the positive projection direction of all detection targets;

[0007] Rearranging the cone beam projection data to obtain parallel beam projection data at different angles;

[0008] Performing orthographic projection detection on each detection target based on each parallel beam projection data to obtain orthographic projection data of each detection target;

[0009] The central orthographic projection image of the detection object is obtained based on the orthographic projection data of each detection target.

[0010] Optionally, the method for rearranging the cone beam projection data includes:

[0011] The cone beam projection data under multiple fields of view are split into rays and then arranged at different angles to obtain parallel beam projection data under different angles.

[0012] Optionally, the rearrangement according to different angles also includes an interpolation processing step.

[0013] Optionally, the method of performing orthographic projection detection on each detection target based on each parallel beam projection data includes: selecting a maximum value from the parallel beam projection data of each detection target at different angles as the orthographic projection data of each detection target.

[0014] Optionally, the method for acquiring the central orthographic projection image of the detection object based on the orthographic projection data of each detection target includes:

[0015] Obtain the orthographic projection angle corresponding to the orthographic projection data of each detection target, and determine whether the orthographic projection angles of each detection target are the same;

[0016] If they are the same, the orthographic projection data of each detection target under the same orthographic projection angle is used to obtain the central orthographic projection image of the detection object;

[0017] If they are different, the orthographic projection data of each detection target are spliced ​​to obtain spliced ​​projection data, and the spliced ​​projection data are used to obtain the central orthographic projection image of the detection object.

[0018] Optionally, the method of continuously scanning a plurality of detection targets in the detection object by using a ray source includes:

[0019] In the computed tomography mode, the detection object is fixed, and the radiation source rotates around the detection object at a preset interval angle to achieve continuous scanning of several detection targets of the detection species, or the radiation source is fixed, and the detection object rotates at a preset interval angle to achieve continuous scanning of several detection targets in the detection object.

[0020] Optionally, the method of continuously scanning a plurality of detection targets in the detection object by using a ray source includes:

[0021] In the computer tomography mode, the detection object is fixed, and the radiation source rotates around the detection object at a preset interval angle to achieve continuous scanning of several detection targets in the detection object; or the radiation source is fixed, and the detection object moves in parallel at a preset interval distance.

[0022] Optionally, the method of continuously scanning a plurality of detection targets in the detection object by using a ray source includes:

[0023] In the computer tomography mode, the radiation source moves in parallel at a preset interval to achieve continuous scanning of several detection targets in the detection object.

[0024] Optionally, the detection target includes an electrode sheet.

[0025] The present invention also provides a computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the method for obtaining a central orthographic projection image of a detection object as described above.

[0026] The present invention also provides a terminal, which includes a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the terminal executes the method for obtaining the central projection image of the detection object as described above.

[0027] As described above, the present invention provides a method for obtaining a central orthographic projection image of a detection object, a readable storage medium, and a terminal, which obtains parallel beam projection data by rearranging cone beam projection data, obtains orthographic projection data by using the parallel beam projection data, and then obtains a central orthographic projection image based on the orthographic projection data, thereby effectively eliminating the cone angle effect of the image and improving the image quality; moreover, by rearranging the cone beam projection data, electrode sheets with different inclination angles can be flattened to the surface we want to observe for detection, thereby improving the electrode sheet detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Shown is a flow chart of the method for obtaining the center orthographic projection image of the detection object according to the present invention.

[0029] Figure 2 Schematic diagram showing the vertically arranged cylindrical array used in the simulation experiment.

[0030] Figure 3 Display as Figure 2 Projected image of the cylindrical array shown.

[0031] Figure 4 Display as Figure 2 Orthographic projection image of the cylindrical array.

[0032] Figure 5Display as Figure 2 The central orthographic projection image is obtained by interpolating the orthographic projection data of the cylindrical array.

[0033] Figure 6 A schematic diagram showing a cylindrical array arranged with a periodic tilt of about -40° and 40° used in a simulation experiment.

[0034] Figure 7 Display as Figure 6 Projected image of the cylindrical array shown.

[0035] Figure 8 Display as Figure 6 The projection image of the cylindrical array shown is obtained based on the parallel projection data.

[0036] Fig. 9 Display as Figure 6 The projected image of the cylindrical array with the orthographic projection direction of -40° is shown.

[0037] Fig.10 Display as Figure 6 The projected image of the cylindrical array with a forward projection direction of 40° is shown.

[0038] Fig.11 Display as Figure 6 The central orthographic projection image is obtained by stitching the orthographic projection data of the cylindrical array shown.

[0039] Fig.12 Shown is a schematic diagram of a cylindrical array arranged at the same interval angle used in a simulation experiment.

[0040] Fig.13 Display as Fig.12 Projected image of the cylindrical array shown.

[0041] Fig.14 Display as Fig.12 The projection image is obtained by interpolating the parallel projection data of the cylindrical array shown.

[0042] Fig.15 Display as Fig.12 Central orthographic projection image of the cylindrical array shown.

[0043] Fig.16 Shown is a schematic diagram of a cylindrical array used in a simulation experiment. The cylindrical array is divided into two groups, one of which is evenly arranged at an inclination angle of 30°, and the other is evenly arranged at an inclination angle of 70°.

[0044] Fig.17 Display as Fig.16 Projected image of the cylindrical array shown.

[0045] Fig.18 Display as Fig.16 Central orthographic projection image of the cylindrical array shown.

[0046] Fig.19 Shown is an electrode sheet array used in a simulation experiment. The electrode sheet array is divided into two groups, one of which is evenly arranged at an inclination angle of 30°, and the other group is evenly arranged at an inclination angle of 70°.

[0047] Fig. 20 Display as Fig.19 Projected image of the electrode patch array shown.

[0048] Fig.21 The display is the parallel projection data of the electrode array and the projection image obtained after interpolation processing.

[0049] Fig. 22 Display as Fig.19 The center of the electrode array is shown as a positive projection image. DETAILED DESCRIPTION

[0050] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0051] See also Figures 1 to 22 It should be noted that the illustrations provided in this embodiment are only schematic illustrations of the basic concept of the present invention. Although the illustrations only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation, the form, quantity and proportion of each component in actual implementation may be changed arbitrarily, and the component layout may also be more complicated.

[0052] like Figure 1 As shown, this embodiment provides a method for obtaining a center projection image of a detection object, and the method includes steps 1), 2), 3) and 4).

[0053] Step 1) Continuously scan a number of detection targets in the detection object using a ray source to collect cone beam projection data in multiple fields of view covering the positive projection direction of all detection targets.

[0054] Specifically, in one example, the method of continuously scanning several detection targets in the detection object using a ray source includes: in a computer tomography (CT) scanning mode, the detection object is fixed, and the ray source rotates around the detection object at a preset interval angle to achieve continuous scanning of several detection targets in the detection object; or the ray source is fixed, and the detection object is rotated at a preset interval angle to achieve continuous scanning of several detection targets in the detection object. For example, the ray source rotates at a preset interval angle of 30°, or the detection object rotates at an angle of 30°, so as to achieve the purpose of continuously scanning several detection targets in the detection object, so as to collect 100 sets of cone beam projection data.

[0055] In this example, in the CT scanning mode, the ray source moves from one side of the detection object to the other side by rotating around the detection object, thereby collecting cone beam projection data under multiple fields of view. When collecting the cone beam projection data under multiple fields of view in the computed tomography mode (CT scanning mode), it is necessary to ensure that the collected data is as continuous as possible. The purpose is to obtain parallel beam projection data with better accuracy after data rearrangement of the cone beam projection data, and then obtain a smoother central orthographic projection image; it is also to ensure that the collected cone beam projection data can include the orthographic projection data of all detection targets, so that the quality of the final central orthographic projection image is guaranteed.

[0056] In practical applications, when the cone beam projection data under multiple fields of view are collected through the CT scanning mode, if a certain detection target is tilted and the tilt angle is too large, the cone beam projection data under more fields of view can be collected by increasing the scanning angle (that is, the angle at which the ray source rotates around the detection object), thereby ensuring that the positive projection data of all detection targets can be covered.

[0057] In another example, a method for continuously scanning a number of detection targets in an object to be detected using a radiation source includes: in a computer tomography (CL) mode, the radiation source moves in parallel at a preset interval distance to achieve continuous scanning of a number of detection targets in the object to be detected, such as the radiation source moves in parallel at a preset interval distance of 0.5 mm or the object to be detected moves at a preset interval of 0.5 mm to continuously scan a number of detection targets in the object to collect 100 sets of cone beam projection data.

[0058] In this example, in the CL scanning mode, the ray source is translated from one side of the inspection object to the other side, thereby collecting cone beam projection data in multiple fields of view.

[0059] In practical applications, when collecting cone beam projection data under multiple fields of view through CL scanning mode, if the inclination angle of a certain detection target is too large, the cone beam projection data under more fields of view can be collected by increasing the total moving distance to ensure that the orthographic projection data of all detection targets can be covered.

[0060] Step 2) Rearranging the cone beam projection data to obtain parallel beam projection data at different angles.

[0061] Specifically, the method for rearranging the cone beam projection data includes: splitting the cone beam projection data under multiple fields of view, and then rearranging them at different angles to obtain parallel beam projection data under different angles. More specifically, the rearranging at different angles also includes an interpolation processing step.

[0062] In this embodiment, the cone beam projection data is the data obtained by the detector after the cone beam X-ray scans the detection object; by splitting the cone beam X-ray in each field of view according to the angle, and arranging the light rays with the same angle in the cone beam X-rays in multiple fields of view according to the distance, parallel light rays with the same angle are obtained, and the projection data corresponding to the parallel light rays at the same angle is a group of parallel beam projection data, wherein the distance is the distance from the ray source to each field of view. In practical applications, the cone beam X-ray can be divided into multiple groups according to a certain angle according to the accuracy of the required central orthographic projection image, for example, each 0.1° is a group, and when the opening angle of the cone beam X-ray is 30°, 300 groups of parallel beam projection data can be obtained.

[0063] When the cone beam projection data is rearranged to obtain parallel beam projection data, since the angle of the X-rays generated by the ray source is discrete, in the process of splitting and recombining the cone beam rays, combined with the computer rounding process, there will be discontinuous values, resulting in some null values ​​in the parallel beam projection data, so interpolation processing can be used to fill the gaps to ensure the quality of the image. There are many types of interpolation, which can be selected according to needs; optionally, this embodiment uses linear interpolation.

[0064] Step 3) Performing orthographic projection detection on each detection target based on each parallel beam projection data to obtain orthographic projection data of each detection target.

[0065] Specifically, the method of performing orthographic projection detection on each detection target based on each parallel beam projection data includes: selecting a maximum value from the parallel beam projection data of each detection target at different angles as the orthographic projection data of each detection target.

[0066] In this embodiment, each detection target corresponds to different parallel beam projection data at different angles, and by comparing the parallel beam projection data corresponding to the same detection target at different angles, finding the maximum value, that is, obtaining the orthographic projection data of the detection target. Using the above method, the orthographic projection data of all detection targets are found.

[0067] Step 4) Acquire the central orthographic projection image of the detection object based on the orthographic projection data of each detection target.

[0068] Specifically, the method for obtaining the central orthographic projection image of the detection object based on the orthographic projection data of each detection target includes: obtaining the orthographic projection angle corresponding to the orthographic projection data of each detection target, and determining whether the orthographic projection angles of each detection target are the same; if they are the same, using the orthographic projection data of each detection target under the same orthographic projection angle to obtain the central orthographic projection image of the detection object; if they are different, splicing the orthographic projection data of each detection target to obtain spliced ​​projection data, and using the spliced ​​projection data to obtain the central orthographic projection image of the detection object.

[0069] In this embodiment, the orthographic projection data of each detection target is the maximum value of its parallel beam projection data, and therefore, the angle corresponding to the maximum value in the parallel beam projection data is the orthographic projection angle of the detection target.

[0070] More specifically, the method of splicing the orthographic projection data of each detection target to obtain the spliced ​​projection data includes: copying the orthographic projection data of each detection target together according to their positional relationship, thereby obtaining the spliced ​​projection data. When splicing is performed specifically, the splicing can be performed in a left-to-right order, or in a right-to-left order, and the splicing method can be selected as needed. The center orthographic projection image of the detection object is obtained using the spliced ​​projection data. The center orthographic projection image is obtained by the spliced ​​projection data, so that the quality of the image is guaranteed.

[0071] Specifically, the detection target includes an electrode sheet. The electrode sheet is arranged in a lithium battery with a small gap and is divided into a positive electrode sheet and a negative electrode sheet. In order to obtain the relative position information between the positive electrode sheet and the negative electrode sheet in the lithium battery, it is necessary to obtain clear images of the positive electrode sheet and the negative electrode sheet. The above method can obtain a clear image of the electrode sheet, effectively improve the image quality, and thus accurately obtain the relative position information of the positive electrode sheet and the negative electrode sheet in the lithium battery.

[0072] See below Figures 2 to 22 , the effect of the method for obtaining the center orthographic projection image of the detection object described in this embodiment is explained in combination with specific simulation experiment results. The detection object in the simulation experiment includes a cylinder and an electrode sheet.

[0073] Figure 2shows an array of vertically arranged cylinders, Figure 3 Yes Figure 2 The cylindrical array shown is scanned in CT scanning mode to obtain a projection image, that is, a projection image under the irradiation of cone beam X-rays. Figure 3 It can be seen that the cylindrical projections on both sides of the projection image are overlapped. Figure 4 The central projection image obtained from the orthographic projection data is shown. Figure 4 It can be seen that the images of the cylinders on both sides in the central orthographic projection image obtained according to the orthographic projection data are also clear, thereby effectively eliminating the cone angle effect. However, due to the presence of null values ​​in the orthographic projection data, the obtained central orthographic projection image is discontinuous, so the projection data needs to be interpolated. Figure 5 The central orthographic projection image obtained after the interpolation process is shown. It can be seen from the figure that the pictures of the central orthographic projection image after the interpolation process are continuous, thereby further improving the image quality.

[0074] Figure 6 The cylindrical array is shown to be arranged in a periodic manner with a left-right tilt at a preset angle, wherein the preset angles are -40° and 40° respectively. Figure 7 for Figure 6 The cylindrical array shown in the figure is scanned by CT scanning mode to obtain a projection image. Figure 8 is a projection image obtained based on parallel beam projection data at a certain angle; Fig. 9 The projection image with an orthographic projection direction of -40° is extracted after interpolation processing of the orthographic projection data. Fig.10 The projection image with an orthographic projection direction of 40° is extracted after interpolation processing of the orthographic projection data. Fig.11 The central orthographic projection image is obtained by splicing the orthographic projection images in the above two orthographic projection directions. Fig.11 It can be seen that the obtained central orthographic projection image effectively eliminates the cone angle effect.

[0075] Fig.12 The cylindrical array is shown with the same interval angle arrangement, the cylindrical array is arranged at an angle from -15° to 15° and at an interval of 3°. Fig.13 for Fig.12 The cylindrical array shown is scanned by CT scanning mode to obtain a projection image. Fig.14 A projection image obtained by interpolating parallel beam projection data at a certain angle; Fig.15 After stitching the orthographic projection data of each cylinder, the central orthographic projection image is obtained according to the stitched projection data. Fig.15 It can be seen that the obtained central orthographic projection image effectively eliminates the cone angle effect.

[0076] Fig.16 A cylindrical array is shown, wherein the cylindrical array includes 8 columns arranged from left to right, 4 columns on the left side form a group and are evenly arranged at an inclination angle of 30°, and 4 columns on the right side form a group and are evenly arranged at an inclination angle of 70°. Fig.17 for Fig.16 The oblique scanning projection image obtained by scanning the cylindrical array shown in the CL scanning mode, Fig.18 is a central orthographic projection image obtained by interpolating the orthographic projection data. Fig.18 It can be seen that the obtained central orthographic projection image effectively eliminates the cone angle effect.

[0077] Fig.19 An electrode sheet array is shown, which includes 8 columns of electrode sheets arranged from left to right, with 4 columns on the left side forming a group and arranged evenly at an inclination angle of 30°, and 4 columns on the right side forming a group and arranged evenly at an inclination angle of 70°. Fig. 20 shows an oblique scanning projection image obtained by scanning the electrode array in CL scanning mode, Fig.21 The projection image is obtained by interpolating the parallel projection data at a certain angle. Fig. 22 To stitch the orthographic projection data of each electrode sheet, and obtain the central orthographic projection image based on the stitched projection data. Fig. 22 It can be seen that the central orthographic projection image obtained by simulation using the electrode sheet also effectively eliminates the cone angle effect.

[0078] Correspondingly, this embodiment further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the method for obtaining the central orthographic projection image of the detection object as described above is implemented.

[0079] Specifically, the computer-readable storage medium may include, but is not limited to, a floppy disk, an optical disk, a CD-ROM (compact disk - read only memory), a magneto-optical disk, a ROM (read only memory), a RAM (random access memory), an EPROM (erasable programmable read-only memory), an EEPROM (electrically erasable programmable read-only memory), a magnetic card or an optical card, a flash memory, or other types of media / machine-readable media suitable for storing machine-executable instructions. In addition, the computer-readable storage medium may be a product that is not connected to a computer device, or may be a component that is connected to a computer device for use.

[0080] Correspondingly, this embodiment also provides a terminal, which includes a processor and a memory, the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the terminal executes the method for obtaining the center projection image of the detection object as described above.

[0081] Specifically, the processor may be a general-purpose processor, including one or more central processing units (CPU), network processors (NP), etc.; it may also be a microcontroller unit (MCU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The memory may include, but is not limited to, high-speed random access memory, non-volatile memory, such as one or more disk storage devices, flash memory devices, or other non-volatile solid-state storage devices.

[0082] In summary, the method, readable storage medium and terminal for obtaining the central orthographic projection image of the detection object of the present invention obtain parallel beam projection data by rearranging the cone beam projection data, obtain orthographic projection data by using the parallel beam projection data, and then obtain the central orthographic projection image based on the orthographic projection data, thereby effectively eliminating the cone angle effect of the image and improving the image quality; moreover, by rearranging the cone beam data, the electrode sheets with different inclination angles can be flattened to the surface we want to observe for detection, thereby improving the detection efficiency of the electrode sheets. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.

[0083] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for obtaining a center orthographic projection image of a detection object, characterized in that: The method comprises: Continuously scanning a number of detection targets in the detection object using a ray source to collect cone beam projection data in multiple fields of view covering the positive projection direction of all detection targets; Splitting the cone beam projection data according to angles, arranging the light rays with the same angle according to distances, so as to obtain parallel beam projection data at different angles; the distance is the distance that the ray source moves from the starting point of the movement to each field of view; Selecting the maximum value from the parallel beam projection data of each detection target at different angles as the positive projection data of each detection target; The central orthographic projection image of the detection object is obtained based on the orthographic projection data of each detection target.

2. The method for obtaining the center orthographic projection image of the detection object according to claim 1, characterized in that: When rearranging at different angles, an interpolation process is also included.

3. The method for obtaining the center orthographic projection image of the detection object according to claim 1, characterized in that: The method for obtaining the central orthographic projection image of the detection object based on the orthographic projection data of each detection target includes: Obtain the orthographic projection angle corresponding to the orthographic projection data of each detection target, and determine whether the orthographic projection angles of each detection target are the same; If they are the same, the orthographic projection data of each detection target under the same orthographic projection angle is used to obtain the central orthographic projection image of the detection object; If they are different, the orthographic projection data of each detection target are spliced ​​to obtain spliced ​​projection data, and the spliced ​​projection data are used to obtain the central orthographic projection image of the detection object.

4. The method for obtaining the center orthographic projection image of the detection object according to claim 1, characterized in that: The method of continuously scanning a plurality of detection targets in the detection object by using a ray source includes: In the computed tomography mode, the detection object is fixed, and the radiation source rotates around the detection object at a preset interval angle to achieve continuous scanning of several detection targets in the detection object; or the radiation source is fixed, and the detection object rotates at a preset interval angle to achieve continuous scanning of several detection targets in the detection object.

5. The method for obtaining the center orthographic projection image of the detection object according to claim 1, characterized in that: The method of continuously scanning a plurality of detection targets in the detection object by using a ray source includes: In the computer tomography mode, the detection object is fixed, and the ray source moves in parallel at a preset interval to achieve continuous scanning of several detection targets in the detection object; or the ray source is fixed, and the detection object moves in parallel at a preset interval.

6. The method for obtaining the center orthographic projection image of the detection object according to claim 1, characterized in that: The detection target includes an electrode sheet.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for obtaining a central orthographic projection image of a detection object as described in any one of claims 1 to 6 is implemented.

8. A terminal, characterized in that: The terminal includes a processor and a memory, the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the terminal executes the method for obtaining a central projection image of a detection object as described in any one of claims 1 to 6.

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