Backscatter detection device, imaging method, equipment and storage medium

Abstract

The embodiment of the present application provides a backscatter detection device and imaging method, equipment and storage medium. The method includes: using a cold cathode X-ray source to work in pulse mode, and modulating the pulsed rays into a fan-shaped ray beam through a front collimator component to solve the contradiction between scanning speed and image quality, and constraining the receiving range of the backscatter detector component to the backscatter photons through the collimation channel formed by the backscatter collimator component, and then the backscatter detector component receives the target backscatter photons passing through the collimation channel, and generates a backscatter electrical signal based on the target backscatter photons and transmits it to the processor, and the processor generates a backscatter image of the inspected object based on the backscatter electrical signal. It avoids the single-frame backscatter data from being affected by the jitter or movement of the detection device, and realizes instant scanning and high-quality dynamic imaging.

Description

Technical Field

[0001] The present application relates to the field of X-ray detection technology, and in particular to a backscatter detection device and an imaging method, equipment and storage medium. Background Art

[0002] Backscatter imaging is an advanced nondestructive testing technology. Its core is to capture and analyze the photons scattered from the object to construct an image of the internal structure of the object. This technology has shown great application potential in many fields, such as material science and safety inspection. However, in practical applications, backscatter imaging technology faces many challenges.

[0003] At present, backscatter detection devices mostly use hot cathode X-ray sources as the radiation source. Although the hot cathode X-ray source has a stable beam, it consumes a lot of power and there is a time delay from turning on the device to outputting a stable beam, which is disadvantageous for the needs of real-time scanning and dynamic imaging. Summary of the invention

[0004] The embodiments of the present application provide a backscatter detection device and an imaging method, equipment and storage medium to solve the problem of how to achieve efficient instant scanning and dynamic imaging.

[0005] In a first aspect, an embodiment of the present application provides a backscatter detection device, comprising: a cold cathode X-ray source assembly, a front collimator assembly, a backscatter detector assembly, a backscatter collimator assembly, and a processor;

[0006] The cold cathode X-ray source assembly is used to emit pulsed rays;

[0007] The front collimator assembly is used to modulate the pulsed rays into a fan-shaped ray beam, the fan-shaped ray beam is used to scan the object to be inspected, and generates backscattered photons corresponding to the object to be inspected after being scattered by the object to be inspected;

[0008] The backscatter collimator assembly is used to form a collimation channel to restrict the receiving range of the backscatter detector assembly to the backscatter photons;

[0009] The backscatter detector assembly is used to receive target backscattered photons passing through the collimation channel and generate backscattered electrical signals based on the target backscattered photons;

[0010] The processor is used to receive the backscattered electrical signal and generate a backscattered image of the inspected object based on the backscattered electrical signal.

[0011] In a second aspect, an embodiment of the present application provides a backscatter imaging method, which is applied to a processor in a backscatter detection device, wherein the backscatter detection device includes: a cold cathode X-ray source component for emitting pulsed rays, a front collimator component for modulating the pulsed rays into a fan-shaped ray beam, a backscatter detector component, a backscatter collimator component, and the processor; the method includes:

[0012] Acquire a backscattered electrical signal of the object under inspection; the backscattered electrical signal is obtained by collecting the backscattered photons of the object under inspection after being screened by the backscatter collimator assembly, and the backscattered photons are scattered by the object under inspection during the scanning of the object under inspection by the fan-shaped beam of rays;

[0013] generating a backscatter image of the object under inspection based on the backscatter electrical signal;

[0014] The fan-shaped beam is obtained by modulating the pulsed rays emitted by the cold cathode X-ray source assembly by the front collimator assembly.

[0015] In a third aspect, an embodiment of the present application provides a processor, including: a storage unit, a processing unit, and a communication component;

[0016] The storage unit stores computer-executable instructions;

[0017] The processing unit executes the computer-executable instructions stored in the storage unit, so that the processing unit executes the above second aspect and / or various possible implementations of the second aspect.

[0018] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the above second aspect and / or various possible implementations of the second aspect.

[0019] In a fifth aspect, an embodiment of the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the above second aspect and / or various possible implementations of the second aspect.

[0020] The backscatter detection device, imaging method, equipment and storage medium provided in the embodiment of the present application adopt a cold cathode X-ray source to work in pulse mode, and modulate the pulsed rays into a fan-shaped ray beam through a front collimator component to solve the contradiction between scanning speed and image quality. The collimation channel formed by the backscatter collimator component is used to constrain the receiving range of the backscatter detector component for backscattered photons, and then the backscatter detector component receives the target backscattered photons passing through the collimation channel, and generates a backscattered electrical signal based on the target backscattered photons and transmits it to the processor, and the processor generates a backscattered image of the object under inspection based on the backscattered electrical signal. This avoids the single-frame backscatter data from being affected by the jitter or movement of the detection device, and realizes instant scanning and high-quality dynamic imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0022] Figure 1 A schematic diagram of the structure of the backscatter detection device provided in this application;

[0023] Figure 2 Schematic diagram of the backscatter imaging method provided in this application Figure 1 ;

[0024] Figure 3 Schematic diagram of the backscatter imaging method provided in this application Figure 2 ;

[0025] Figure 4 Schematic diagram of the backscatter imaging method provided in this application Figure 3 ;

[0026] Figure 5 Schematic diagram of the effect of posture change parameters on visible light visual images;

[0027] Figure 6 Schematic diagram of the backscatter imaging method provided in this application Figure 4 ;

[0028] Figure 7 Schematic diagram of the backscatter imaging method provided in this application Figure 5 ;

[0029] Figure 8 It is a schematic diagram of the backscatter image matrix grid;

[0030] Fig. 9 A schematic diagram of the structure of the processor provided in this application.

[0031] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0032] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0033] First, the terms involved in this application are explained:

[0034] Backscatter imaging technology refers to an imaging technology that obtains the internal structure of the object being inspected by detecting backscattered photons from the object and its spatial distribution;

[0035] The hot cathode X-ray source is based on the principle of thermal electron emission. When a material with a very high melting and boiling point (such as tungsten) is used as the cathode, the cathode can be heated to a very high temperature. As it is heated, the increased energy enables electrons to be released from the cathode (such as tungsten filament) through thermal electron emission. These electrons are accelerated by the electric field to form a high-speed electron beam. When the electron beam hits a metal target (such as a tungsten target), bremsstrahlung occurs, generating X-rays;

[0036] The cold cathode X-ray source uses a carbon nanostructure electron source to draw out electron beams by applying a positive voltage. These electron beams are focused and converged, bombarding the anode target surface at high speed, thereby generating X-rays. Compared with traditional hot cathode X-ray tubes, cold cathode rays do not require heating;

[0037] Backscatter imaging is an advanced non-destructive testing technology. Its core is to capture and analyze the photons scattered from the inside of the object to construct an image of the internal structure of the object. This technology has shown great application potential in many fields, such as material science and safety inspection. However, in practical applications, especially in the field of handheld devices, backscatter imaging technology faces many challenges.

[0038] The scanning method commonly used in backscatter imaging technology is flying spot scanning, that is, the beam is modulated into a pencil beam by a collimator, scanning the object point by point, and coordinating with translational motion to achieve two-dimensional scanning, thereby obtaining a complete backscatter image. In actual operation, the switching speed of flying spot scanning and the speed of translational motion need to be coordinated with each other, otherwise there will be omissions or repeated scanning points, affecting the imaging effect. This effect will be more prominent in handheld devices that cannot guarantee stability; compared with line scanning and surface scanning, flying spot scanning has lower scanning speed and imaging efficiency, and takes longer time.

[0039] At present, most backscatter detection devices use hot cathode X-ray sources, which have the advantage of stable beam current. However, since electrons are generated by heating the cathode filament, it consumes a lot of power; and it takes a while for the tungsten filament to be heated and reach a stable temperature state. Therefore, there is a time delay from turning on the device to outputting a stable beam current.

[0040] In view of the above problems, the present application provides a backscatter detection device and an imaging method, device and storage medium, which not only ensures the instant scanning of the detection device, but also improves the quality of dynamic imaging. Specifically, in the backscatter detection device, due to the limitation of space and weight, the power of the hot cathode X-ray source is very small. During the detection work, only a small current or voltage can be maintained. When detecting objects with large thickness or density, the image quality will be reduced, and it may be impossible to obtain an image reflecting the internal information of the object; if a high-quality image is obtained by reducing the scanning speed, the scanning time will be increased; and, taking a handheld detection device as an example, considering that it is difficult for the staff to maintain a stable moving state for a long time during the detection process of the handheld device, increasing the scanning time will introduce interference such as image jitter, and it may still be impossible to obtain a high-quality image; similar to the handheld detection device, mobile backscatter scanning vehicles, backscatter scanning robots and other mobile backscatter imaging devices all have the problem of backscatter image blurring caused by the jitter of the mobile device, such as the jitter of the staff, the vibration of the holding device and the mobile device itself, and the jitter of the imaging device caused by the unevenness of the moving plane of the equipment are all potential influencing factors of this problem. Taking these issues into consideration, the inventors studied whether it is possible to use fan-shaped beams and linear array detectors to achieve line scanning imaging to resolve the contradiction between scanning speed and image quality; using a cold cathode X-ray source working in pulse mode, the extremely short pulse duration can resolve the image blur and distortion problems caused by various jitter factors during scanning, while achieving instant scanning and improving the quality of dynamic imaging. Moreover, a ray source with a larger tube voltage range can be used to make the backscatter detection device suitable for various occasions with different penetration capabilities. Based on this, the present application scheme is proposed.

[0041] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0042] Figure 1 A schematic diagram of the backscatter detection device provided in this application is shown in FIG. Figure 1 As shown, the device includes: a cold cathode X-ray source component-1, a front collimator component-2, a backscatter detector component, a backscatter collimator component and a controller. Among them, the cold cathode X-ray source component-1 emits pulsed rays, which can be a single-focus structure or a distributed multi-focus structure; the front collimator component-2 modulates and collimates the pulsed rays into a fan-shaped ray beam and shields the initial rays in other directions; the backscatter detector component includes a linear array detector-3 and a linear array detector-4, which are respectively located on both sides of the fan-shaped ray beam and receive backscattered photons from the object under inspection at the same time; the backscatter collimator component includes a backscatter collimator-5 and a backscatter collimator-6, which form multiple collimation channels to constrain the receiving range of the backscatter detector for backscattered photons, such as Figure 1 The right side is a side view of the linear array detector-4 and the backscatter collimator-6. When the fan-shaped beam of rays is irradiated on the object to be inspected, backscattered photons are generated. Only when the backscattered photons that pass through the blank channel of the backscatter collimator-6 hit the linear array detector-4 can they be detected by the linear array detector-4. After the linear array detector-3 and the linear array detector-4 detect the backscattered photons, they can convert the backscattered photons into backscattered electrical signals, which are then sent to the processor. The processor can generate backscattered image data based on the received backscattered electrical signals. After the object to be inspected is completely scanned, the processor splices multiple backscattered image data to obtain the backscattered image corresponding to the object to be inspected. The staff can detect the internal structure and hidden objects of the object to be inspected based on the information of the backscattered image.

[0043] Optionally, the backscatter detection device may also include a visible light vision component-8, which works synchronously with the X-ray imaging, that is, the visible light vision component and the X-ray simultaneously scan the object to be inspected (the "simultaneously" here can be understood as the visible light vision component also collects images of the object to be inspected during the scanning and detection of the object to be inspected by X-rays), and is used to obtain the posture change of the device relative to the object to be inspected at each X-ray imaging moment, thereby assisting in the registration of the X-ray imaging data at adjacent moments and solving the problem of backscatter image jitter. It should be noted that in order to ensure that the visible light vision component-8 works synchronously with the cold cathode X-ray source component, the emission time of the pulsed ray should be less than or equal to the exposure time of the visible light vision component-8, so as to obtain the backscatter image data and the visible light vision image at the same moment.

[0044] Optionally, the visible light vision component-8 can be arranged at any position where the image of the inspected object can be collected. For example, the visible light vision component-8 can be located in the detection channel and on the scanning surface of the ray beam.

[0045] Correspondingly, after receiving the visible light visual image scanned by the visible light visual component-8, the processor determines the posture change parameters of the backscatter detection device relative to the object to be inspected based on the preset reference visual image and the visible light visual image, and further corrects the backscatter image based on the posture change parameters to obtain a corrected backscatter image. The jitter parameter analysis is realized by using the visible light image, and the jitter correction is performed on the backscatter image, thereby effectively solving the image blur problem caused by device jitter or movement.

[0046] Further optionally, the visible light visual image and the backscattered image involved in the correction may be acquired at the same time to ensure the correction effect.

[0047] Optionally, the reference visual image may be a visible light visual image collected at any sampling time, or the first visible light visual image collected at the beginning of scanning, or a visible light visual image collected in advance before scanning. The present embodiment of the application does not specifically limit the selection of the reference visual image.

[0048] In a possible implementation, the backscatter detection device further includes a pulse high voltage power supply control component-9. The pulse high voltage power supply control component-9 controls the generation and shutdown of the pulse high voltage applied by the grid of the cold cathode, and can adjust the period and duty cycle of the pulse high voltage as required, thereby controlling the generation of the pulse X-ray beam.

[0049] The period of pulse high voltage refers to the length of time required for the pulse signal to repeat from the beginning. In one period, the pulse signal will go from low level to high level and then back to low level. This periodic change is one of the basic characteristics of the pulse signal.

[0050] In the pulse high voltage power supply control component-9, the cycle can be adjusted as needed. By adjusting the cycle, the emission frequency of the pulse X-ray beam can be controlled, that is, the number of times the pulse X-ray beam is emitted per unit time.

[0051] The duty cycle of pulse high voltage refers to the proportion of high-level signal in a pulse cycle. Specifically, it is the ratio of the high-level duration in the pulse signal to the entire cycle time. The duty cycle is usually expressed as a percentage, and the calculation formula is: Duty cycle = (high-level duration / cycle time) × 100%.

[0052] In the pulse high voltage power supply control component-9, the duty cycle can also be adjusted as needed. By adjusting the duty cycle, the duration of the pulse X-ray beam, that is, the emission time length of each pulse X-ray beam, can be controlled.

[0053] For example, the cold cathode X-ray source component-1 is a single-focus structure, and the pulsed rays are controlled and emitted by the pulsed high-voltage power supply control component-9. The pulse period and duty cycle can be adjusted according to the requirements of the detection scene, moving speed or imaging speed. When the moving speed is slow, a longer pulse period can be used to obtain better image quality; when thicker objects need to be detected, the duty cycle can be increased to obtain more initial X-rays and better image quality; when thinner objects are detected, the duty cycle can be reduced to reduce image blur caused by factors such as hand shaking and movement.

[0054] It should be noted that in one pulse cycle, an X-ray beam is emitted once to obtain a column of backscattered image data. In this case, the duration of the pulsed ray emitted by the ray source in a single pulse cycle is extremely short, and the duration of the pulsed ray is determined by the duty cycle. Since the duration of the pulsed ray is extremely short, it can be considered that the detection device is relatively static in a very short time, that is, the backscattered image data obtained in each sampling time will not be disturbed by factors such as the jitter of the staff or the movement of the detection device, and there will be no image blurring problem caused by this.

[0055] In another possible implementation, the backscatter detection device may further include a low-energy filter assembly-7. The low-energy filter assembly-7 absorbs X-rays with lower energy in the fan-shaped beam, thereby reducing the proportion of components in the X-ray beam that contribute less to backscatter imaging and reducing the radiation dose in the scanning area. The assembly is a replaceable assembly, so that it can be disassembled and replaced under different operating voltages of the radiation source.

[0056] Optionally, the filter assembly-7 can be arranged at any position on the rear side of the front collimator assembly-2 and parallel to the front collimator assembly-2.

[0057] It should be noted that the direction in which the backscatter detection device scans the object to be inspected is perpendicular to the plane where the fan-shaped beam of rays is located.

[0058] Figure 2 Schematic diagram of the backscatter imaging method provided in this application Figure 1 ,like Figure 2 As shown, the method is applied to a processor of a backscatter detection device, wherein the backscatter detection device comprises: a cold cathode X-ray source assembly for emitting pulsed rays, a front collimator assembly for modulating the pulsed rays into a fan-shaped ray beam, a backscatter detector assembly, a backscatter collimator assembly, and a processor. The method specifically comprises:

[0059] S201: Acquire the backscattered electrical signal of the object under inspection.

[0060] S202: Generate a backscatter image of the inspected object based on the backscatter electrical signal.

[0061] Among them, the backscattered electrical signal is obtained by the backscattered photons of the object being inspected being screened by the backscatter collimator component and then collected by the backscatter detector component. The backscattered photons are scattered by the object being inspected during the scanning process of the fan-shaped beam of rays on the object being inspected.

[0062] After the object under inspection is scattered, the scattered photons formed will pass through the collimation channel formed by the backscatter collimator assembly to reach the backscatter detector assembly, and then the backscatter detector assembly will convert them into backscatter electrical signals and transmit them to the processor.

[0063] After receiving the backscattered electrical signals, the processor converts all the backscattered electrical signals into backscattered image data and splices them to obtain a backscattered image.

[0064] The specific implementation of each component of the backscatter detection device in the embodiment of the present application is the same as the implementation of each component in the aforementioned embodiment, and will not be repeated here.

[0065] It should be noted that the collimation channel is a key component of the backscatter collimator assembly-5 and the backscatter collimator assembly-6, which is responsible for spatially constraining and guiding the backscattered photons from the inspected object. Through the collimation channel, only the target backscattered photons with a specific direction and energy can be received by the linear array detector-3 and the linear array detector-4, which helps to reduce background noise and interference and improve imaging quality.

[0066] The backscatter detector assembly receives backscattered photons and converts them into electrical signals. The converted electrical signals are usually very weak, so they need to be amplified. Optionally, the amplified electrical signals also need to be filtered, digitized, and other processing steps to remove noise and interference and improve the signal-to-noise ratio and reliability of the signal.

[0067] The processor integrates the electrical signals into digital image data, thereby obtaining a backscattered image of the inspected object, which contains information such as the internal structure of the inspected object.

[0068] The backscatter imaging method provided in the embodiment of the present application obtains the backscatter electrical signal of the inspected object; the backscatter electrical signal is obtained by the backscatter photons of the inspected object being screened by the backscatter collimator component and then collected by the backscatter detector component, and the backscatter photons are scattered by the inspected object during the scanning of the inspected object by the fan-shaped beam; based on the backscatter electrical signal, a backscatter image of the inspected object is generated; wherein the fan-shaped beam is obtained by modulating the pulsed rays emitted by the cold cathode X-ray source component by the front collimator component. The method uses a cold cathode X-ray source component to emit pulsed rays, and modulates, filters and collimates the rays through a series of components, and finally generates a backscatter image of the inspected object. A higher image acquisition efficiency is achieved, the problem of the contradiction between the scanning speed and the image quality in the backscatter detection device is solved, the single-frame backscatter data is avoided from being affected by the jitter or movement of the detection device, and instant scanning and high-quality dynamic imaging are achieved.

[0069] Figure 3 Schematic diagram of the backscatter imaging method provided in this application Figure 2 ,like Figure 3 As shown, based on the above embodiment, the backscatter detection device further includes a visible light vision component, and the method further includes:

[0070] S301: Acquire a visible light visual image of the inspected object.

[0071] S302: Determine the posture change parameters of the object under inspection based on the preset reference visual image and the visible light visual image. In this step, after receiving the visible light visual image scanned by the visible light visual component-8, the processor can determine the posture change parameters of the backscatter detection device relative to the object under inspection based on the visible light visual image in order to avoid image distortion.

[0072] Specifically, for the visible light visual image data at each moment in the visible light visual image, image registration is performed on the visible light visual image data based on the reference visual image to obtain the registration parameters corresponding to the visible light visual image data, and according to the pre-set structural parameters corresponding to the backscattering detection device, the registration parameters corresponding to the visible light visual image data are converted to obtain the posture change parameters of the backscattering image data corresponding to the moment of the visible light visual image data.

[0073] S303: Correcting the backscattered image based on the posture change parameter to obtain a corrected backscattered image.

[0074] In this step, after obtaining the posture change parameters of the backscatter image data corresponding to each moment, the processor stores them. After completing the scanning of the object to be inspected, the processor corrects the backscatter image data at each moment in the backscatter image based on the posture change parameters at each moment, thereby obtaining a corrected backscatter image.

[0075] Specifically, for each moment, the processor corrects the backscatter image data corresponding to the moment based on the posture change parameter corresponding to the moment, until the backscatter image data at each moment in the backscatter image is corrected to obtain a corrected backscatter image.

[0076] Optionally, the reference visual image may be a visible light visual image used at any sampling moment, or the first visible light visual image collected at the beginning of scanning, or a visible light visual image collected in advance before scanning. The present application embodiment does not specifically limit the selection of the reference visual image.

[0077] The backscatter imaging method provided in the embodiment of the present application obtains a visible light visual image of the inspected object, determines the posture change parameters based on the preset reference visual image and the visible light visual image, and corrects the backscatter image based on the posture change parameters to obtain a corrected backscatter image. The backscatter imaging system is combined with the visible light visual system, and the jitter parameter analysis is realized using the visible light image, and the jitter correction is performed on the backscatter image, thereby effectively solving the image blur problem caused by the jitter or movement of the detection device.

[0078] Figure 4 Schematic diagram of the backscatter imaging method provided in this application Figure 3 ,like Figure 4 As shown, based on the above embodiment, step S303 specifically includes:

[0079] S401: for the visible light visual image data at each moment in the visible light visual image, based on the reference visual image, image registration is performed on the visible light visual image data to obtain registration parameters corresponding to the visible light visual image data.

[0080] In this step, in order to solve the image distortion and blurring problems caused by factors such as shaking or movement of the detection device, an image registration algorithm is used to analyze the visible light visual image data at each moment to obtain registration parameters.

[0081] Specifically, in order to improve image quality, reduce noise and distortion, and provide high-quality input for subsequent registration steps. The visible light visual image data at each moment can also be preprocessed, for example, grayscale, if the image is in color, first convert it to a grayscale image, because grayscale images require less computation when processed and usually do not affect the accuracy of registration; denoising, using filters (such as Gaussian filters, median filters, etc.) to remove noise in the image; enhancement, enhancing the contrast of the image through methods such as histogram equalization and contrast stretching, making the features more obvious, and then extracting key points or features for registration from the image data. For example, key point detection: Use algorithms (such as SIFT, SURF, ORB, etc.) to detect key points in the image, which are usually parts of the image that have little change and are easy to identify. Feature description: Generate a feature descriptor for each key point, which is used to find a match between the reference image and the image to be registered, and find the correspondence between feature points between the reference image and the image to be registered. For example, brute force matching: for each feature point in the image to be registered, search for the nearest feature point in the reference image for matching; FLANN matching: use the fast nearest neighbor search library (FLANN) for matching; screening matching: use the RANSAC algorithm or other methods to remove incorrect matching points and retain only reliable matching pairs. According to the matched feature points, estimate the transformation model from the image to be registered to the reference image, such as affine transformation, non-rigid transformation, etc. Apply the transformation model to transform the image to be registered to a position aligned with the reference image. Use interpolation methods (such as bilinear interpolation, bicubic interpolation, etc.) to calculate the value of each pixel in the transformed image, merge multiple images into one, and use image fusion techniques such as weighted averaging, multi-resolution fusion, etc. The transformation parameters obtained during the output registration process are the registration parameters.

[0082] S402: According to the preset structural parameters corresponding to the backscatter detection device, the registration parameters corresponding to the visible light visual image data are converted to obtain the posture change parameters of the backscatter image data corresponding to the time of the visible light visual image data.

[0083] In this step, after obtaining the registration parameters, for a detection device with a fixed structure, the posture change parameters of the visible light vision component-8 and the backscatter imaging system installed in the same device relative to the object under inspection can be obtained by converting the structural parameters.

[0084] Specifically, the registration parameters of visible light visual image data are analyzed. The registration parameters usually describe the relative transformation between images, such as:

[0085] Translation vector: describes the movement of the image in the x, y, and z directions.

[0086] Rotation matrix: describes the rotation of an image around the x, y, and z axes.

[0087] To convert the registration parameters of the visible light image into the posture change parameters of the backscattered image data, coordinate transformation is required. For example:

[0088] Coordinate system definition: define two coordinate systems, one is the coordinate system of the visible light vision component-8, and the other is the coordinate system of the backscatter detector component.

[0089] Coordinate transformation: Use the structural parameters to transform the points in the visible light image into the coordinate system of the backscatter detector.

[0090] Attitude parameter calculation: Based on the transformed coordinates, the attitude change parameters of the backscattered image data are calculated. This usually involves matrix operations on the transformed coordinates to obtain the rotation matrix and translation vector.

[0091] Exemplarily, a visible light image with a large field of view is collected as a reference image before scanning begins, and a visible light image and a column of backscattered images are simultaneously acquired in each subsequent sampling time; an image registration algorithm is used to analyze the registration parameters of each visible light image and the reference image, and the posture change parameters of the detection device are obtained, including the translation and rotation angles along the X, Y, and Z axes. Figure 5 The effect of posture change parameters on visible light visual images is shown in Figure 2. The effect of each posture change on the backscattered image data is shown in Figure 2. Figure 5 As shown, the backscatter detector only acquires one column of backscatter image data in each sampling time. The posture change of the detection device can be converted into a coordinate system with the center of the single column to be measured as the origin and the plane to be measured as the yz plane through the coordinate system. The translation and rotation of the detection device along the X, Y, and Z axes can be expressed as a combination of the translation and rotation of the detection device relative to the center of the single column to be measured.

[0092] The backscatter imaging method provided in the embodiment of the present application performs image registration on the visible light visual image data at each moment in the visible light visual image based on the reference visual image to obtain the registration parameters corresponding to the visible light visual image data, and converts the registration parameters corresponding to the visible light visual image data according to the pre-set structural parameters corresponding to the backscatter detection device to obtain the posture change parameters of the backscatter image data corresponding to the moment of the visible light visual image data. This method can significantly improve the image registration accuracy, the accuracy of obtaining the posture change parameters, the image correction effect, the detection efficiency and automation, the adaptability and flexibility, and the system robustness by performing image registration on the image data at each moment in the visible light visual image and converting the posture change parameters of the backscatter image data accordingly.

[0093] Figure 6 Schematic diagram of the backscatter imaging method provided in this application Figure 4,like Figure 6 As shown, based on the above embodiment, step S303 specifically includes:

[0094] S601: For each moment, correct the backscattered image data corresponding to the moment based on the posture change parameter corresponding to the moment.

[0095] S602: until the backscatter image data at each moment in the backscatter image is corrected, a corrected backscatter image is obtained.

[0096] After scanning the inspected object, each backscatter image data in the backscatter image is corrected according to the posture change parameter corresponding to each moment until the entire backscatter image is corrected, thereby obtaining a corrected backscatter image.

[0097] The backscatter imaging method provided in the embodiment of the present application corrects the backscatter image data corresponding to each moment based on the posture change parameter corresponding to the moment, until the backscatter image data at each moment in the backscatter image is corrected to obtain a corrected backscatter image. By correcting the backscatter image data according to the posture change parameter at each moment, the image quality and accuracy, detection accuracy and reliability, detection efficiency and automation, adaptability and flexibility, and system robustness can be significantly improved, thereby solving the image distortion and blurring problems caused by factors such as jitter or movement of the detection device.

[0098] Figure 7 Schematic diagram of the backscatter imaging method provided in this application Figure 5 ,like Figure 7 As shown, based on the above embodiment, step S601 specifically includes:

[0099] S701: For each moment, the posture change parameter corresponding to the moment includes a displacement change parameter, and the backscattered image data corresponding to the moment is corrected according to the displacement change of at least one coordinate axis indicated by the displacement change parameter by using a displacement correction formula corresponding to at least one coordinate axis.

[0100] and / or,

[0101] S702: If the posture change parameter corresponding to the moment includes an angle change parameter, the backscattered image data corresponding to the moment is corrected according to the rotation change of at least one coordinate axis indicated by the angle change parameter and by using a rotation correction formula corresponding to at least one coordinate axis.

[0102] The posture change parameters may include displacement change parameters and angle change parameters, or may include both of the above change parameters. Based on the posture change parameter type, the backscatter image data is corrected.

[0103] Exemplarily, if the displacement change parameter indicates an X-axis displacement change, the backscattered image data corresponding to the moment is corrected based on a preset X-axis correction formula; if the displacement change parameter indicates a Y-axis displacement change, the backscattered image data corresponding to the moment is corrected based on a preset Y-axis correction formula; if the displacement change parameter indicates a Z-axis displacement change, the backscattered image data corresponding to the moment is corrected based on a preset Z-axis correction formula.

[0104] According to the above embodiments, the displacement change parameter may include any one or more of the XYZ displacement change parameters, and the displacement change parameter of each axis is checked, and then the backscatter image data is corrected according to the corresponding correction formula.

[0105] For example, the detection device is translated along the X-axis relative to the origin: the posture will cause the backscatter imaging field of view to be scaled, and the center of the backscatter imaging field of view remains unchanged. The image scaling factor caused by the translation along the X-axis is obtained by analyzing the visible light visual image. , then the actual imaging field of view of each backscatter detector is The ideal imaging field of view of times, that is:

[0106]

[0107] , the imaging field of view remains unchanged; , the imaging field of view is enlarged; , the imaging field of view is reduced. For the i-th pixel, its coordinate in the original image is

[0108]

[0109] Its coordinates mapped to the actual imaging are:

[0110]

[0111]

[0112] The corresponding pixel values ​​are:

[0113]

[0114] The detection device is translated along the Y axis relative to the origin: the posture will cause the backscatter imaging center to translate along the Y axis, and the backscatter imaging field of view remains unchanged. The distance of translation along the Y axis is obtained by analyzing the visible light visual image. , the coordinates in the original image The coordinates mapped to the actual image are:

[0115]

[0116]

[0117] The corresponding pixel values ​​are:

[0118]

[0119] The detection device is translated along the Z axis relative to the origin: the posture will cause the backscatter imaging center to translate along the Z axis, and the backscatter imaging field of view remains unchanged. The distance of translation along the Z axis is obtained by analyzing the visible light visual image. , the coordinates in the original image The coordinates mapped to the actual image are:

[0120]

[0121]

[0122] The corresponding pixel values ​​are:

[0123]

[0124] If the angle change parameter indicates an X-axis rotation change, the backscattered image data corresponding to the moment is corrected based on a preset X-axis rotation correction formula; if the angle change parameter indicates a Y-axis rotation change, the backscattered image data corresponding to the moment is corrected based on a preset Y-axis rotation correction formula; if the angle change parameter indicates a Z-axis rotation change, the backscattered image data corresponding to the moment is corrected based on a preset Z-axis rotation correction formula.

[0125] According to the above embodiments, the angle variation parameter may include any one or more of the XYZ angle variation parameters, and the angle variation parameter of each axis is checked, and then the backscatter image data is corrected according to the corresponding correction formula.

[0126] For example, the detection device rotates along the X-axis relative to the origin: the posture will cause the backscatter imaging field of view to rotate, and the center of the backscatter imaging field of view remains unchanged. The angle of rotation along the X-axis is obtained by analyzing the visible light visual image. , then the actual imaging field of view of each backscatter detector remains unchanged, but Changes occurred:

[0127]

[0128] Coordinates in the original image The coordinates mapped to the actual image are:

[0129]

[0130]

[0131] The corresponding pixel values ​​are:

[0132]

[0133] The detection device rotates along the Y axis relative to the origin: the posture will cause the backscatter imaging field of view to be enlarged, and the center of the backscatter imaging field of view remains unchanged. The rotation angle along the Y axis is obtained by analyzing the visible light visual image , then the magnification of the backscatter imaging field of view caused by this is , the backscatter imaging data can be corrected by using an interpolation algorithm, which is the same as the translation of the detection device relative to the origin along the X-axis;

[0134]

[0135]

[0136] The corresponding pixel value is

[0137]

[0138] The detection device rotates along the Z axis relative to the origin: the posture will cause the backscatter imaging field of view to scale, and the center of the backscatter imaging field of view will translate along the Y axis.

[0139]

[0140]

[0141] The corresponding pixel values ​​are:

[0142]

[0143] The backscatter imaging method provided in the embodiment of the present application is that for each moment, the posture change parameter corresponding to the moment includes a displacement change parameter, then according to the displacement change of at least one coordinate axis indicated by the displacement change parameter, the backscatter image data corresponding to the moment is corrected by a displacement correction formula corresponding to at least one coordinate axis, and / or, the posture change parameter corresponding to the moment includes an angle change parameter, then according to the rotation change of at least one coordinate axis indicated by the angle change parameter, the backscatter image data corresponding to the moment is corrected by a rotation correction formula corresponding to at least one coordinate axis. The above method can significantly improve image quality and accuracy, detection accuracy and reliability, detection efficiency and user experience, and system adaptability and robustness by comprehensively considering the posture change parameters at each moment and correcting the backscatter image data frame by frame accordingly, thereby solving the image distortion and blurring problems caused by factors such as jitter or movement of the detection device.

[0144] For example, Figure 8 is a schematic diagram of the backscatter image matrix grid, such as Figure 8 As shown, the left side is an uncorrected backscatter image matrix grid, and the right side is a backscatter image matrix grid corrected based on any correction method in the aforementioned embodiments. Based on the corrected backscatter image matrix grid, the final corrected backscatter image is obtained by a method not limited to two-dimensional interpolation.

[0145] Optionally, a hot cathode X-ray source may also be applicable to the method provided in any embodiment of the present application while solving or optimizing problems such as rising edge delay.

[0146] Similar to handheld devices, trackless mobile backscatter imaging devices such as mobile backscatter scanning vehicles and backscatter scanning robots all have the problem of blurred backscatter images caused by the jitter of the mobile device. For example, jitter of the staff, vibration of the holding device and the mobile device itself, and jitter of the imaging device caused by the unevenness of the moving plane of the equipment are all potential influencing factors of this problem. Therefore, the scope of protection of the present application includes but is not limited to handheld backscatter detection devices, and can also be mobile backscatter detection devices, wherein the mobile backscatter detection device can include a backscatter scanning detection vehicle or a backscatter detection robot, etc.

[0147] Fig. 9 This is a schematic diagram of the structure of the processor provided in this application. Fig. 9 As shown, the processor 900 provided in this embodiment includes: at least one processing unit 901 and a storage unit 902. Optionally, the processor 900 also includes a communication component 903. The processing unit 901, the storage unit 902 and the communication component 903 are connected via a bus 04.

[0148] In the specific implementation process, at least one processing unit 901 executes the computer execution instructions stored in the storage unit 902, so that at least one processing unit 901 executes the above method.

[0149] The specific implementation process of the processing unit 901 can be found in the above method embodiment, and its implementation principle and technical effect are similar, so this embodiment will not be repeated here.

[0150] In the above embodiments, it should be understood that the processing unit can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the invention can be directly implemented as a hardware processor, or can be implemented by a combination of hardware and software modules in the processor.

[0151] The storage unit may include a high-speed memory (Random Access Memory, RAM), and may also include a non-volatile memory (NVM), such as at least one disk storage.

[0152] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, the bus in the drawings of this application is not limited to only one bus or one type of bus.

[0153] The present application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0154] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processing unit executes the computer-executable instructions, the above method is implemented.

[0155] The above-mentioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general or special-purpose computer.

[0156] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (Application Specific Integrated Circuits, referred to as: ASIC). Of course, the processor and the readable storage medium can also exist in the device as discrete components.

[0157] The division of units is only a logical function division, and there may be other divisions in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0158] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0159] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0160] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0161] Those skilled in the art can understand that all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk and other media that can store program codes.

[0162] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A backscatter detection device, characterized in that: include: Cold cathode X-ray source assembly, front collimator assembly, backscatter detector assembly, backscatter collimator assembly, processor and pulse high voltage power supply control assembly; The cold cathode X-ray source assembly is used to emit pulsed rays; The front collimator assembly is used to modulate the pulsed rays into a fan-shaped ray beam, the fan-shaped ray beam is used to scan the object to be inspected, and generates backscattered photons corresponding to the object to be inspected after being scattered by the object to be inspected; The backscatter collimator assembly is used to form a collimation channel to restrict the receiving range of the backscatter detector assembly to the backscatter photons; The backscatter detector assembly is used to receive target backscattered photons passing through the collimation channel and generate backscattered electrical signals based on the target backscattered photons; The processor is used to receive the backscattered electrical signal and generate a backscattered image of the inspected object based on the backscattered electrical signal; The pulse high voltage power supply control component is used to control the cold cathode X-ray source component to emit the pulse ray based on the pulse period and duty cycle; The pulse high-voltage power supply control component is also used to increase the pulse period when the moving speed of the detected object acquired in advance is less than a preset speed threshold; and / or, The pulse high-voltage power supply control component is also used to increase the duty cycle when the pre-acquired thickness information of the inspected object is greater than a preset thickness threshold, or to decrease the duty cycle when the thickness information of the inspected object is less than the thickness threshold.

2. The device according to claim 1, characterized in that The device also includes a visible light vision component; The visible light vision component is used to scan the inspected object simultaneously with the fan-shaped ray beam to generate a visible light vision image; The emission time of the pulse ray is within the exposure time range of the visible light vision component.

3. The device according to claim 2, characterized in that The processor is further configured to receive the visible light visual image, and determine a posture change parameter of the device relative to the detected object based on a preset reference visual image and the visible light visual image; The processor is further configured to correct the backscatter image based on the posture change parameter to obtain a corrected backscatter image.

4. The device according to claim 1, characterized in that The device also includes a low-energy filter assembly; The low-energy filter assembly is used for absorbing low-energy X-rays in the fan-shaped ray beam.

5. The device according to claim 3, characterized in that The reference visual image is any one of the following images: a visible light visual image used at any sampling moment, the first visible light visual image collected at the beginning of scanning, and a visible light visual image collected in advance before the beginning of scanning.

6. The device according to claim 1, characterized in that The device comprises: a handheld backscatter detection device or a mobile backscatter detection device; and / or, The low energy filter assembly is arranged at the rear side of the front collimator assembly, at any position parallel to the front collimator assembly.

7. A backscatter imaging method, characterized in that: A processor used in a backscatter detection device, the backscatter detection device comprising: a cold cathode X-ray source assembly for emitting pulsed rays, a front collimator assembly for modulating the pulsed rays into a fan-shaped ray beam, a backscatter detector assembly, a backscatter collimator assembly, the processor, and a pulsed high-voltage power supply control assembly; the method comprising: Acquire a backscattered electrical signal of the object under inspection; the backscattered electrical signal is obtained by collecting the backscattered photons of the object under inspection after being screened by the backscatter collimator assembly, and the backscattered photons are scattered by the object under inspection during the scanning of the object under inspection by the fan-shaped beam of rays; generating a backscatter image of the object under inspection based on the backscatter electrical signal; Wherein, the fan-shaped ray beam is obtained by modulating the pulsed ray emitted by the cold cathode X-ray source assembly by the front collimator assembly; the pulsed high-voltage power supply control assembly is used to control the cold cathode X-ray source assembly to emit the pulsed ray based on the pulse period and duty cycle; The pulse high-voltage power supply control component is also used to increase the pulse period when the moving speed of the detected object acquired in advance is less than a preset speed threshold; and / or, The pulse high-voltage power supply control component is also used to increase the duty cycle when the pre-acquired thickness information of the inspected object is greater than a preset thickness threshold, or to decrease the duty cycle when the thickness information of the inspected object is less than the thickness threshold.

8. The method according to claim 7, characterized in that The backscatter detection device further includes a visible light vision component; the method further includes: Acquire a visible light visual image of the inspected object, wherein the visible light visual image is acquired during a process in which the visible light visual component scans the inspected object; Determining a posture change parameter of the object under inspection based on a preset reference visual image and the visible light visual image; the posture change parameter is used to represent a relative position change between the object under inspection and the backscatter detection device; The backscatter image is corrected based on the posture change parameter to obtain a corrected backscatter image.

9. The method according to claim 8, characterized in that The determining of the posture change parameter based on the preset reference visual image and the visible light visual image includes: For the visible light visual image data at each moment in the visible light visual image, based on the reference visual image, performing image registration on the visible light visual image data to obtain registration parameters corresponding to the visible light visual image data; According to the preset structural parameters corresponding to the backscatter detection device, the registration parameters corresponding to the visible light visual image data are converted to obtain the posture change parameters of the backscatter image data corresponding to the moment of the visible light visual image data.

10. The method according to claim 8, characterized in that The step of correcting the backscatter image based on the posture change parameter to obtain a corrected backscatter image includes: For each moment, correcting the backscattered image data corresponding to the moment based on the posture change parameter corresponding to the moment; Until the backscatter image data at each moment in the backscatter image is corrected, the corrected backscatter image is obtained.

11. The method according to claim 10, characterized in that The correcting the backscattered image data corresponding to the moment based on the posture change parameter corresponding to the moment includes: For each moment, the posture change parameter corresponding to the moment includes a displacement change parameter, and according to the displacement change of at least one coordinate axis indicated by the displacement change parameter, the backscattered image data corresponding to the moment is corrected by a displacement correction formula corresponding to the at least one coordinate axis; and / or, The posture change parameter corresponding to the moment includes an angle change parameter. According to the rotation change of at least one coordinate axis indicated by the angle change parameter, the backscattered image data corresponding to the moment is corrected by a rotation correction formula corresponding to the at least one coordinate axis.

12. The method according to claim 8, characterized in that The reference visual image is any one of the following images: a visible light visual image used at any sampling moment, the first visible light visual image collected at the beginning of scanning, and a visible light visual image collected in advance before the beginning of scanning.

13. A processor, characterized in that: include: Storage unit, processing unit, communication components; The storage unit stores computer-executable instructions; The processing unit executes the computer-executable instructions stored in the storage unit, so that the processor executes the method according to any one of claims 7 to 12.

14. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 7 to 12 when executed by a processor.

Images