An image processing method, system and device for computer stratigraphic imaging

Abstract

Embodiments of the present application provide an image processing method, system and device for computer layered imaging, by performing image reconstruction based on known projection data to obtain a first three-dimensional reconstruction image, performing forward projection on an upper image layer with a layer number in an upper layer interval and a lower image layer with a layer number in a lower layer interval respectively to obtain projection data corresponding to the upper image layer and projection data corresponding to the lower image layer, reconstructing a second three-dimensional reconstruction image of a detection object based on the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer, updating a middle image layer of the first three-dimensional reconstruction image by using a middle image layer of the second three-dimensional reconstruction image to obtain an updated three-dimensional reconstruction image of the detection object, and restoring the internal structure of the reconstruction image by correcting the projection data to improve the image quality and the interlayer resolution.

Description

Technical Field

[0001] This application relates to the field of X-ray imaging technology, and in particular to an image processing method, system and device for computer-aided layered imaging. Background Technology

[0002] X-ray computed tomography (CT) technology can detect the internal structure of an object without touching its surface or damaging its internal structure, thus solving the problems of aliasing and obstruction that exist in X-ray transmission imaging.

[0003] In industrial applications, for plate structures such as printed circuit boards, wings, and satellite solar panels, which have a large length-to-thickness ratio, CT inspection is difficult because the tested components are not easy to rotate or the inspection space is limited, making it difficult to scan them from all angles. This results in missing projection information, finite angle artifacts in the reconstructed image, and the inability to obtain complete structural information or discover internal defects, leading to poor inspection results. Summary of the Invention

[0004] The purpose of this application is to provide an image processing method, system, and device for computer-aided layered imaging (CL) to suppress the problem of interlayer information aliasing in CL reconstructed images. The specific technical solution is as follows:

[0005] This application provides an image processing method for computer-aided layered imaging, the method comprising:

[0006] Based on the known projection data obtained by scanning the object of detection using a layered imaging scanning device, a first three-dimensional reconstructed image of the object of detection is reconstructed; wherein, the first three-dimensional reconstructed image includes a preset number of image layers in a preset direction;

[0007] Forward projection is performed on the upper image layer (which is in the upper layer range) and the lower image layer (which is in the lower layer range) to obtain the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer.

[0008] Based on the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer, a second three-dimensional reconstructed image of the detected object is reconstructed; wherein, the second three-dimensional reconstructed image includes the preset number of image layers in the preset direction;

[0009] The middle layer of the second 3D reconstructed image is used to update the middle layer of the first 3D reconstructed image to obtain the updated 3D reconstructed image of the detected object; wherein, the middle layer is an image layer with a layer number in the middle range, the middle range is an image layer range to be corrected for artifacts, and the upper range, the middle range and the lower range are obtained by dividing the preset number of ranges. The interlayer artifact information included in the second 3D reconstructed image is less than the interlayer artifact information included in the first 3D reconstructed image.

[0010] This application also provides a computer-aided layered imaging system, including:

[0011] X-ray source, detector, controller, and processor;

[0012] The controller is used to control the radiation source and the detector;

[0013] The radiation source is used to emit X-rays;

[0014] The detector is used to acquire X-ray images;

[0015] The processor is configured to: reconstruct a first three-dimensional reconstructed image of the detected object based on known projection data obtained by scanning the detected object using a layered imaging scanning device; wherein the first three-dimensional reconstructed image includes a preset number of image layers in a preset direction; perform forward projection on the upper image layer (within the upper layer range) and the lower image layer (within the lower layer range) to obtain projection data corresponding to the upper image layer and projection data corresponding to the lower image layer; and reconstruct a second three-dimensional reconstructed image of the detected object based on the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer. The second 3D reconstructed image includes the preset number of image layers in the preset direction; the middle image layer of the first 3D reconstructed image is updated using the middle image layer of the second 3D reconstructed image to obtain the updated 3D reconstructed image of the detected object; wherein the middle image layer is an image layer with a layer number in the middle range, the middle range is an image layer range to be corrected for artifacts, and the upper range, the middle range and the lower range are obtained by dividing the preset number of ranges; the interlayer artifact information included in the second 3D reconstructed image is less than the interlayer artifact information included in the first 3D reconstructed image.

[0016] This application also provides an image processing apparatus for computer-generated layered imaging, used to execute the image processing method for computer-generated layered imaging described in any of the embodiments of this application.

[0017] This application also provides an electronic device, including: a processor and a memory;

[0018] Memory, used to store computer programs;

[0019] The processor, when executing a program stored in memory, implements any of the above-described image processing methods for computer-aided layered imaging.

[0020] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements any of the above-described image processing methods for computer-aided layered imaging.

[0021] This application also provides a computer program product containing instructions that, when run on a computer, cause the computer to perform any of the above-described image processing methods for computer-generated layered imaging.

[0022] Beneficial effects of the embodiments in this application:

[0023] The image processing method, apparatus, electronic device, computer-readable storage medium, and computer program product containing instructions for computer-aided layered imaging provided in this application embodiment reconstruct a first three-dimensional reconstructed image by performing image reconstruction based on known projection data. The method then projects an upper image layer (located in the upper layer range) and a lower image layer (located in the lower layer range) forward to obtain projection data corresponding to the upper and lower image layers. Based on the projection data of the upper and lower image layers, a second three-dimensional reconstructed image of the detected object is reconstructed. The middle image layer of the first three-dimensional reconstructed image is updated using the middle image layer of the second three-dimensional reconstructed image to obtain an updated three-dimensional reconstructed image of the detected object. By correcting the projection data, the second three-dimensional reconstructed image contains less interlayer artifact information than the first three-dimensional reconstructed image, which helps to restore the internal structure of the reconstructed image and improve image quality and interlayer resolution.

[0024] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0026] Figure 1-1 A schematic diagram of a CL imaging device is provided for an embodiment of this application;

[0027] Figure 1-2 This is a schematic diagram of the imaging principle of the CL imaging device provided in the embodiments of this application;

[0028] Figure 1-3 A schematic diagram of a planar layered imaging scanning method for detecting a circuit board provided in an embodiment of this application;

[0029] Figure 1-4 A schematic flowchart of a first method for image processing in computer-aided layered imaging provided in an embodiment of this application;

[0030] Figure 1-5 This is a second flowchart illustrating an image processing method for computer-aided layered imaging provided in an embodiment of this application.

[0031] Figure 1-6 A schematic diagram of a third process for an image processing method for computer-aided layered imaging provided in an embodiment of this application;

[0032] Figure 1-7 This is a schematic diagram showing the results of iterative reconstruction of different layers of a circuit board provided in an embodiment of this application;

[0033] Figure 1-8 This is a schematic diagram of the iterative reconstruction result of the BGA solder ball portion provided in an embodiment of this application;

[0034] Figure 1-9 A schematic diagram illustrating the effect of interlayer artifact correction on different layers of a circuit board according to an embodiment of this application;

[0035] Figure 1-10 A schematic diagram illustrating the effect of interlayer artifact correction for the BGA solder ball portion provided in an embodiment of this application;

[0036] Figure 2 A schematic diagram of a computer layered imaging system provided in an embodiment of this application;

[0037] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0038] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0039] First, the terms used in the embodiments of this application will be explained:

[0040] Computed tomography (CT) is a technique that uses an X-ray source to emit X-rays, a detector to receive photons after the X-rays penetrate the object under test at different angles, and an image reconstruction algorithm to obtain a tomographic or three-dimensional image of the object. It solves the problems of aliasing and occlusion that exist in X-ray transmission imaging.

[0041] Computed laminograph (CL): Similar to CT imaging, it is a generalized application of CT. It is primarily used for detecting plate-like or shell-like objects.

[0042] Forward projection (abbreviated as forward projection): The process of obtaining the projection of an object at different angles or in different directions.

[0043] Back projection (abbreviated as back projection): The process of reconstructing the internal attenuation coefficient of an object from the projection data, also known as image reconstruction.

[0044] OS-SART (Ordered-subset Simultaneous Algebraic Reconstruction Techniques) is an iterative algorithm that first discretizes a continuous image and then reconstructs the image using a discrete model from CT imaging.

[0045] Artifacts are various forms of images that do not exist in the original scanned object but appear in the reconstructed image.

[0046] Interlayer artifacts: During CL reconstruction, due to the data acquisition process, the reconstructed image may have severe interlayer information aliasing. This type of artifact is called interlayer artifact.

[0047] The CL imaging device consists of an X-ray source, a front collimator, a turntable, a detector, and an image processing unit. Its composition and imaging principle are as follows: Figure 1-1 , Figure 1-2 As shown.

[0048] The imaging process is as follows: X-rays are emitted from the X-ray source, pass through the collimator, penetrate the object being measured, and are received by the detector. The detector converts the received attenuated X-rays into electrical signals through a photoelectric converter, and then into digital signals through a digital-to-analog converter. The main server performs image reconstruction, and after reconstruction, the digital-to-analog converter converts the reconstructed X-rays back into analog signals. Finally, the images are displayed on the monitor in different grayscale formats or stored directly in the computer in digital format.

[0049] When inspecting board-like objects such as circuit boards, a planar layered imaging scanning method is often used, such as... Figure 1-3 As shown.

[0050] In this scanning method, the stage is fixed, and the circuit board is placed on the stage. The focal point of the X-ray source, the center of the stage, and the center of the detector are always aligned on a straight line, with an angle α (0° < α < 90°) with the rotation axis Z. The X-ray source and detector rotate synchronously relative to each other around the Z-axis to complete data acquisition. The distances from the center of the X-ray source trajectory to the center of the stage, the distances from the center of the X-ray source trajectory to the center of the detector trajectory, the rotation radius r of the X-ray source, the rotation radius R of the detector, the angle α, the scanning speed, the rotation direction, and the magnification ratio are all adjustable, making operation convenient and flexible. While analytical or iterative reconstruction algorithms can obtain three-dimensional tomographic images of objects, both methods suffer from severe interlayer artifacts due to overlapping information, reducing the interlayer resolution and making it difficult to determine structural components or defects, thus diminishing the practicality of the CL system.

[0051] To suppress the problem of interlayer information aliasing in CL reconstructed images, embodiments of this application provide an image processing method, system, apparatus, electronic device, computer-readable storage medium, and computer program product containing instructions for computer-aided layered imaging.

[0052] In this application embodiment, the solution can be applied to any electronic device that can provide image processing services for computer-generated layered imaging, such as a computer, mobile phone, tablet, game console, portable wearable device, etc. The image processing method for computer-generated layered imaging provided in this application embodiment can be implemented in at least one of software, hardware circuits, and logic circuits within an electronic device.

[0053] like Figure 1-4 As shown, Figure 1-4 This is a first flowchart illustrating an image processing method for computer-aided layered imaging provided in an embodiment of this application. The method includes:

[0054] S01, based on the known projection data obtained by scanning the detection object using a layered imaging scanning device, a first three-dimensional reconstructed image of the detection object is reconstructed; wherein, the first three-dimensional reconstructed image includes a preset number of image layers in a preset direction.

[0055] S02, perform forward projection on the upper image layer in the upper layer interval and the lower image layer in the lower layer interval respectively to obtain the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer.

[0056] S03, based on the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer, a second three-dimensional reconstructed image of the detected object is reconstructed; wherein, the second three-dimensional reconstructed image includes the preset number of image layers in the preset direction.

[0057] S04, using the middle layer image of the second 3D reconstructed image, update the middle layer image of the first 3D reconstructed image to obtain the updated 3D reconstructed image of the detected object; wherein, the middle layer image is an image layer with a layer number in the middle range, the middle range is the image layer range to be corrected for artifacts, and the upper range, the middle range, and the lower range are obtained by dividing the preset number of ranges. The interlayer artifact information included in the second 3D reconstructed image is less than the interlayer artifact information included in the first 3D reconstructed image.

[0058] Based on the principle of CL imaging, a layered imaging scanning device can scan the object to obtain projection data and scanning geometric parameters of the object at different angles. For example, the layered imaging scanning device can be a CL imaging device. The scanning geometric parameters include the distance from the center of the X-ray source trajectory to the center of the stage, the distance from the center of the X-ray source trajectory to the center of the detector trajectory, the rotation radius of the X-ray source, the rotation radius of the detector, the rotation range of the X-ray source and detector, the number of rotation divisions, the detector size, the number of detectors, geometric correction parameters, etc. Then, the electronic device can obtain the known projection data and scanning geometric parameters of the object from the computer-generated layered imaging device. For example, the electronic device can be part of the CL imaging device or a separate device; this application does not limit this.

[0059] After obtaining the known projection data and scanning geometric parameters of the computer-generated layered imaging of the object to be detected, image reconstruction can be performed to obtain the first three-dimensional reconstructed image of the object. The image reconstruction method can be OS-SART, analytical class reconstruction algorithm (FDK), BPF (Back projection filter), or other iterative algorithms such as SART (Algebraic reconstruction technique), SIRT (Simultaneous Iterative Reconstruction), MLEM (Statistical Iterative Reconstruction), EM (Expectation-maximization algorithm), etc. This application does not impose any limitations on these methods.

[0060] The first 3D reconstructed image includes a preset number of image layers in a preset direction. This preset direction is related to the scanning direction of the layered scanning of the detected object. For example, if the detected object is scanned in layers according to its thickness direction, then the preset direction can be the thickness direction of the detected object. Further exemplarily, the number of layers (preset number) of the first 3D reconstructed image can be determined based on the resolution of the computer layered imaging and the size (e.g., thickness) of the detected object in the scanning direction. For example, a higher resolution image can have more layers, while a lower resolution image can have fewer layers. The specific number can be determined based on the actual situation. For example, the total number of layers in the first 3D reconstructed image and the thickness of each layer can be determined based on the resolution or the thickness of the object. Then, each layer of the image is matched with the actual part of the detected object. For example, if the thickness of the detected object is 100mm, the total number of layers in the first 3D reconstructed image of the detected object can be determined to be 100 layers, and the thickness of each layer is 1mm. Based on the total number of layers and the thickness of the detected object, that is, 0-1mm of the imaged object corresponds to the first layer, 1-2mm corresponds to the second layer, and so on, 99mm-100mm corresponds to the 100th layer.

[0061] If the image layer requiring artifact correction is located in the middle, the first 3D reconstructed image can be divided into upper, middle, and lower intervals based on the layer number of the image layer requiring artifact correction (the image layer to be corrected). Specifically, after determining the middle interval according to the top-to-bottom order of the first 3D reconstructed image in a preset direction, the image layers above the middle interval are designated as the upper interval, and the image layers below the middle interval are designated as the lower interval.

[0062] For example, the number of layers of the reconstructed image is determined based on the system resolution and the thickness of the object being detected, resulting in the total number of image layers of the first three-dimensional reconstructed image; the image layers to be corrected for artifacts are determined based on actual needs; and the middle layer interval is determined based on the image layers to be corrected for artifacts, wherein the middle layer interval is the interval of the image layers to be corrected for artifacts.

[0063] After determining the upper, middle, and lower intervals, the upper image layer of the upper interval and the lower image layer of the lower interval are projected forward using scanning geometric parameters to obtain the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer. The method of projecting forward using scanning geometric parameters to the upper image layer of the upper interval and the lower image layer of the lower interval of the first 3D reconstructed image can refer to the forward projection method in related technologies.

[0064] Based on the projection data corresponding to the upper and lower image layers, a second 3D reconstructed image of the detected object is obtained. This second 3D reconstructed image contains less interlayer artifact information than the first 3D reconstructed image. The reduction in the amount of projection data corresponding to the upper and lower image layers involved in reconstructing the second 3D reconstructed image reduces the artifact effects caused by the upper and lower image layers.

[0065] In one optional implementation, a second three-dimensional reconstructed image of the detected object is reconstructed based on the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer, including:

[0066] Based on the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer, updated projection data is obtained by reducing the proportion of the projection data component corresponding to the upper image layer and / or reducing the proportion of the projection data component corresponding to the lower image layer in the known projection data of the detected object. Wherein, at least one of the projection data components corresponding to the upper image layer and the projection data components corresponding to the lower image layer can be reduced according to image processing requirements. In cases where at least one of the projection data components corresponding to the upper image layer and the projection data components corresponding to the lower image layer can be reduced, the specific projection data update scheme in this application embodiment is not specifically limited.

[0067] Image reconstruction is performed based on the updated projection data to obtain a second three-dimensional reconstructed image of the detected object.

[0068] For example, based on the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer, determining the updated projection data obtained by reducing the proportion of the projection data component corresponding to the upper image layer and / or reducing the proportion of the projection data component corresponding to the lower image layer in the known projection data may include:

[0069] Based on known projection data, projection data corresponding to the upper image layer, a first preset weighting factor for the projection data corresponding to the upper image layer, projection data corresponding to the lower image layer, and a second preset weighting factor for the projection data corresponding to the lower image layer, projection data calculation is performed to obtain updated projection data. The second 3D reconstructed image obtained based on the updated projection data reduces the influence of the projections of the upper and lower image layers on the projection of the middle image layer. The specific implementation of the projection calculation is not specifically limited in this application embodiment; the calculation formula can be reasonably designed based on the factors in the aforementioned calculation.

[0070] Alternatively, the updated projection data can be determined using the following formula:

[0071] p′=p-w1*proj_up-w2*proj_down

[0072] Where p′ is the updated projection data, p is the known projection data, proj_up is the projection data corresponding to the upper image layer, proj_down is the projection data corresponding to the lower image layer; w1 is the first preset weight factor, and w2 is the second preset weight factor.

[0073] The intermediate image layer of the first 3D reconstructed image is updated using the intermediate image layer of the second 3D reconstructed image. That is, the intermediate image layer of the first 3D reconstructed image is replaced with the intermediate image layer of the second 3D reconstructed image to obtain an updated 3D reconstructed image of the detected object.

[0074] A first 3D reconstructed image is obtained by reconstructing the image based on known projection data. Forward projection is then performed on the upper image layer (located in the upper layer range) and the lower image layer (located in the lower layer range) to obtain the projection data corresponding to the upper and lower image layers. Based on the projection data of the upper and lower image layers, a second 3D reconstructed image of the detected object is reconstructed. The middle image layers of the first 3D reconstructed image are updated using the middle image layers of the second 3D reconstructed image to obtain an updated 3D reconstructed image of the detected object. By correcting the projection data, the second 3D reconstructed image contains fewer interlayer artifacts than the first 3D reconstructed image, which helps to restore the internal structure of the reconstructed image and improves image quality and interlayer resolution.

[0075] In this embodiment of the application, for example, the middle layer of the first 3D reconstructed image is updated using the middle layer of the second 3D reconstructed image to obtain the final 3D reconstructed image of the detected object. This can be performed using a cyclical update method. That is, when the upper limit of the middle layer interval where the middle layer image layer is located is less than the preset middle layer upper limit (determined by the total number of middle layers that need to be corrected for artifacts), the interval ranges of the upper, middle, and lower intervals can be updated according to a preset step size. Based on the updated interval ranges of the upper, middle, and lower intervals, the execution step is returned: the upper image layer in the upper interval and the lower image layer in the lower interval are forward projected to obtain the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer; until the upper limit of the updated middle interval is greater than or equal to the preset middle layer upper limit, the updated 3D reconstructed image is used as the final 3D reconstructed image of the detected object. That is, during the cyclical update process, the range of the upper, middle and lower intervals changes continuously with the update progress, requiring repeated execution of image layer projection operation, second 3D reconstruction image reconstruction operation and middle image layer update operation.

[0076] For example, it can be explained as follows:

[0077] Based on the current image layer segmentation parameters and preset step size, the image layers are divided into a first interval image layer, a second interval image layer, and a third interval image layer; wherein, the first interval image layer is located above the second interval image layer, and the third interval image layer is located below the second interval image layer.

[0078] The first interval image layer and the third interval image layer are projected forward respectively to obtain the projection data corresponding to the first interval image layer and the projection data corresponding to the third interval image layer.

[0079] Based on the projection data corresponding to the first interval image layer and the projection data corresponding to the third interval image layer, the third three-dimensional reconstructed image of the detected object is reconstructed.

[0080] Using the second interval image layer of the third 3D reconstructed image, the middle layer image layer of the first 3D reconstructed image is updated to obtain the fourth 3D reconstructed image;

[0081] If the current image layer division parameter is less than the maximum number of layers in the above-mentioned middle layer interval (i.e., the preset upper limit of the middle layer), update the above-mentioned first three-dimensional reconstructed image to the above-mentioned fourth three-dimensional reconstructed image, and increase the value of the image layer division parameter; return to the execution step: based on the current image layer division parameter and the preset step size, divide the first interval image layer, the second interval image layer and the third interval image layer;

[0082] Until the updated image segmentation parameters obtained by adding a preset step size to the current image layer segmentation parameters are greater than the maximum number of layers in the above-mentioned middle layer interval, the fourth 3D reconstructed image obtained in the current loop is used as the updated 3D reconstructed image of the above-mentioned detection object.

[0083] The image layer to be corrected for artifacts is determined. Based on the layer number of the image layer to be corrected, the current image layer partitioning parameters and step size are determined. The step size represents the total number of image layers to be corrected in one loop. The current image layer partitioning parameters can represent the first image layer of the image currently undergoing artifact correction. Based on the current image layer partitioning parameters and the preset step size, the first 3D reconstructed image is divided into a first interval image layer, a second interval image layer, and a third interval image layer. The first, second, and third interval image layers are all located in different image layers, with the second interval image layer belonging to the image layer to be corrected for artifacts. In other words, the image layer to be corrected for artifacts can be determined based on the image layer partitioning parameters. The initial value of the image layer partitioning parameters can be the layer number of the first image layer to be corrected for artifacts. Taking a 100mm thick object as an example, we need to observe the structural information of the 30mm to 50mm portion of the object. However, this portion suffers from severe interlayer artifacts, requiring correction of the image layers in this area. For instance, if the first 3D reconstructed image of the object comprises 100 image layers, with the 30mm to 50mm portion corresponding to layers 30 to 50, then the initial value of the image layer segmentation parameter can be 30. When segmenting the first 3D reconstructed image into image layers, the second segment image layer belongs to layers 30 to 50. This second segment image layer can be layers 30 to 50, or a portion of layers 30 to 50. The image layer segmentation parameter can be determined based on the number of layers 30 to 50, as long as the segmented second segment image layer belongs to layers 30 to 50.

[0084] For example, if the current image layer partitioning parameter is m and the step size is t, based on the current image layer partitioning parameter m, the images from layer 1 to layer m-1 are determined as the first interval image layer, the images from layer m+t to layer M are determined as the third interval image layer, and the images from layer m to layer m+t-1 are determined as the second interval image layer; where the total number of image layers is M, t is a preset integer, and m < (m+t). <M,1≤t<M。

[0085] Since each layer of the image of the detected object is projected orthogonally, contributing to the projection, processing a large number of layers at once (with a large t value, such as t=30) can lead to significant inter-layer interference, even if the influence of layers (1 to m-1) and (m+t) to M on layers (m) to (m+t-1) is reduced. Therefore, layers t in the middle may still experience significant interference. To address this, a step size representing the total number of image layers for artifact correction in one cycle can be set. This allows for batch processing of the image layers to be corrected, further improving image quality. The step size can be set based on actual conditions to minimize interference between layers.

[0086] For example, the step size can be set based on the total number of image layers to be corrected for artifacts. While minimizing interference between layers, if the total number of image layers to be corrected can be divided equally, then the step size is preferentially set based on dividing the total number of image layers to be corrected for artifacts into multiple equal groups. For example, t can be set to a relatively small value to obtain multiple clear images of the detected object. When t is set relatively small, the process can be repeated cyclically, correcting all image layers that need artifact correction through multiple processing steps. By continuously correcting artifacts layer by layer multiple times, not only can the image quality of the focal plane layer be guaranteed, but the image quality of layers far from the focal plane layer can also be significantly improved, increasing the utilization rate of scanning data and the practicality of the CL system.

[0087] Moreover, this method can achieve good results when there is little projection data (such as 32 projection data), and the processing effect will be more obvious when the amount of projection data increases.

[0088] For example, the number of layers of the reconstructed image is determined based on the system resolution and the thickness of the detected object, resulting in the total number of image layers of the first three-dimensional reconstructed image; the image layer to be corrected for artifacts is determined according to actual needs; the current image layer partitioning parameters and step size are determined based on the image layer to be corrected for artifacts, so that the second interval image layer determined based on the current image layer partitioning parameters and step size belongs to the image layer for artifact correction.

[0089] After determining the first, second, and third image layers, forward projection is performed on the first and third image layers using scanning geometric parameters, respectively, to obtain the projection data for the first and second image layers. The method of forward projection using scanning geometric parameters for the first and second image layers can refer to forward projection methods in related technologies. Then, based on the projection data corresponding to the first and third image layers, a third-dimensional reconstructed image of the detected object is obtained.

[0090] Using the second interval image layer of the third 3D reconstructed image, update the middle layer image layer of the first 3D reconstructed image to obtain the fourth 3D reconstructed image. If the current image layer division parameter is less than the maximum number of layers in the middle interval, update the first 3D reconstructed image to the fourth 3D reconstructed image and increase the value of the image layer division parameter. Return to the execution step: Based on the current image layer division parameter and the preset step size, divide the first interval image layer, the second interval image layer, and the third interval image layer until the updated image division parameter obtained by adding the preset step size value to the current image layer division parameter will be greater than the maximum number of layers in the middle interval. Then, use the fourth 3D reconstructed image obtained in the current update loop as the updated 3D reconstructed image of the detection object.

[0091] Continuing with the above-described cyclic update example, in one possible embodiment, the reconstruction of the third 3D reconstructed image of the detected object based on the projection data corresponding to the first interval image layer and the projection data corresponding to the third interval image layer includes:

[0092] Based on the known projection data, the first preset weight factor, the second preset weight factor, the projection data corresponding to the first interval image layer, and the projection data corresponding to the third interval image layer, the updated projection data is determined; the first preset weight factor and the second preset weight factor are both determined based on practical experience.

[0093] Based on the updated projection data, image reconstruction is performed to obtain a third 3D reconstructed image.

[0094] The first preset weight factor represents the projection weight of the first interval image layer onto the known projection data, and the second preset weight factor represents the projection weight of the third interval image layer onto the known projection data. The updated projection data determined based on the known projection data, the first preset weight factor, the second preset weight factor, the projection data corresponding to the first interval image layer, and the projection data corresponding to the third interval image layer can reduce the influence of the projection of the first interval image layer and the third interval image layer on the projection of the second interval image layer. Thus, the third 3D reconstructed image obtained by image reconstruction based on the updated projection data reduces the influence of the projection of the first interval image layer and the third interval image layer on the projection of the second interval image layer.

[0095] In one possible embodiment, determining the updated projection data based on the known projection data, the first preset weighting factor, the second preset weighting factor, the projection data corresponding to the first interval image layer, and the projection data corresponding to the third interval image layer includes:

[0096] The updated projection data is determined using the following formula:

[0097] p′=p-w1*proj_up-w2*proj_down

[0098] Where p′ is the updated projection data, p is the known projection data, proj_up is the projection data corresponding to the first interval image layer, proj_down is the projection data corresponding to the third interval image layer; w1 is the first preset weight factor, and w2 is the second preset weight factor.

[0099] Based on the above formula, the updated projection data reduces the impact of the projections of the first and third interval image layers on the projection of the second interval image layer.

[0100] Based on the above embodiments, such as Figure 1-5 As shown, Figure 1-5 This is a second flowchart illustrating an image processing method for computer-aided layered imaging provided in an embodiment of this application. The method includes:

[0101] S110, acquire the known projection data and scanning geometric parameters obtained by the layered imaging scanning device scanning the object to be detected;

[0102] S120, based on the above-mentioned known projection data and the above-mentioned scanning geometric parameters, image reconstruction is performed to obtain a first three-dimensional reconstructed image;

[0103] S130, based on the current image layer division parameters and preset step size, divide the first interval image layer, the second interval image layer and the third interval image layer;

[0104] S140, using the above scanning geometric parameters, the first interval image layer and the third interval image layer are projected forward to obtain the projection data of the first interval image layer and the third interval image layer respectively.

[0105] S150, based on the known projection data, the first preset weight factor, the second preset weight factor, the projection data of the first interval image layer and the projection data of the third interval image layer, a third three-dimensional reconstructed image is determined, wherein the first preset weight factor represents the projection weight of the first interval image layer on the known projection data, and the second preset weight factor represents the projection weight of the third interval image layer on the known projection data.

[0106] S160, update the second interval image layer of the first three-dimensional reconstructed image using the second interval image layer of the third three-dimensional reconstructed image to obtain the fourth three-dimensional reconstructed image;

[0107] S170, if the current image layer division parameter is less than the preset parameter threshold (i.e., the maximum number of layers in the aforementioned middle layer interval), update the first three-dimensional reconstructed image to the fourth three-dimensional reconstructed image, increase the value of the image layer division parameter, and return to step S130.

[0108] For example, the values ​​of the image layer segmentation parameters can be increased in the following way:

[0109] The current image layer segmentation parameter value is increased by t to obtain the updated image layer segmentation parameter.

[0110] For example, taking a 100mm thick object as an example, we need to observe the structural information of the 30mm to 50mm section. However, due to severe interlayer artifacts in this section, the image layers in this part need to be corrected. The current image layer division parameters are 30 (m), 5 (t), and a preset threshold of 50. This means the first interval image layers are 1-29, the third interval is 35-100, and the second interval is 30-34. If the current image layer division parameter 30 is less than the preset threshold of 50, the first 3D reconstructed image is updated to the fourth 3D reconstructed image. Then, 't' is added to the current image layer division parameter value to obtain the updated image layer division parameters. Based on the updated parameters, the first interval image layers are determined to be 1-34, the third interval to be 40-100, and the second interval to be 35-39. Adding 't' to the current image layer division parameter value as the updated parameter avoids repeated processing of the same layer, thus reducing computational load.

[0111] S180, until the updated image segmentation parameters obtained by adding a preset step size value to the current image layer segmentation parameters are greater than the preset parameter threshold, the fourth 3D reconstructed image obtained in the current update cycle is used as the updated 3D reconstructed image of the detection object.

[0112] A first 3D reconstructed image is obtained by reconstructing the image based on known projection data and scanning geometric parameters. Based on the current image layer division parameters and preset step size, a first interval image layer, a second interval image layer, and a third interval image layer are divided. The first interval image layer and the third interval image layer are forward projected using scanning geometric parameters to obtain the projection data of the first interval image layer and the third interval image layer, respectively. Based on the known projection data, a first preset weight factor, a second preset weight factor, and the projection data of the first interval image layer and the third interval image layer, a third 3D reconstructed image is determined. The second interval image layer of the first 3D reconstructed image is updated using the second interval image layer of the third 3D reconstructed image. By correcting the projection data, the internal structure of the reconstructed image is restored, and the image quality and inter-layer resolution are improved.

[0113] In one possible embodiment, the reconstruction of the first three-dimensional reconstructed image of the detected object based on the known projection data obtained by the layered imaging scanning device from scanning the detected object includes:

[0114] Acquire known projection data and scanning geometric parameters obtained by the layered imaging scanning device from scanning the object to be detected;

[0115] Obtain the current reconstructed image; wherein the initial value of the current reconstructed image is a preset image;

[0116] Based on the above scanning geometric parameters, the first projection data of the current reconstructed image in the forward projection direction is determined;

[0117] If the difference between the known projection data and the first projection data is not less than a preset difference threshold, or if the difference between the known projection data and the first projection data is not less than a preset difference threshold and the preset number of iterations has not been reached, the current reconstructed image is updated, and the execution step is returned: Determine the first projection data of the current reconstructed image in the forward projection direction based on the above scanning geometric parameters.

[0118] If the difference between the known projection data and the first projection data is less than a preset difference threshold, or if the difference between the known projection data and the first projection data is less than a preset difference threshold and a preset number of iterations has been reached, the current reconstructed image is used as the first 3D reconstructed image.

[0119] The essence of iterative reconstruction is to use known projection data p and scanning geometric parameters to perform back projection to obtain a reconstructed image. Then, using the known geometric parameters, the reconstructed image is forward projected to obtain projection data p1. This projection data p1 is compared with the known projection data p, and after correcting p1, image reconstruction is performed again. This process is repeated until the iteration termination condition is met, yielding the final reconstruction result. Of course, a preset number of iterations can also be used as an upper limit to determine the final reconstruction result.

[0120] Specifically, after obtaining the known projection data p and scanning geometric parameters L, the initial values ​​of the current reconstructed image are obtained. These initial values ​​can be set to all zeros (which can also be understood as a preset image), or they can be the analytically reconstructed image, for example, setting the initial value f of the estimated image. (0) =0, setting the iteration termination condition ε or the upper limit of the number of iterations N. The image is projected forward using the scanning geometry parameters to obtain the projection data p0. This p0 is compared with the known projection data p. If the error between p0 and p is not less than a preset difference threshold or the number of iterations has not reached the upper limit, taking the Ordered-subset Simultaneous Algebraic Reconstruction Techniques (OS-SART) algorithm as an example, it is used to reconstruct the image from the CL projection data p, obtaining the current reconstructed image f. (k) Model f (k) The model is:

[0121]

[0122] Update to be based on f (0) Get f (1) Then, the scanning geometry parameters are used to apply f(1) The projection data p1 of the image is obtained by performing forward projection. It is compared with the known projection data p. If the error between p and p1 is not less than the preset difference threshold or the number of iterations has not reached the upper limit, the iteration is continued based on the above formula. If the error is less than the preset difference threshold or the number of iterations has reached the upper limit, the first three-dimensional reconstructed image is obtained.

[0123] Here, the projected data image is divided into N = n × n pixels, p i This represents the known projection data of the i-th ray. w represents the projection data of the current reconstructed image for the i-th ray. in , where is the weighting factor, representing the contribution of the nth pixel to the projection value of the i-th ray; B represents the correction value for j pixels based on a preset image reconstruction algorithm. [n] λ is the ray index set of the nth subset; λ is the relaxation factor used to control the weights of the corrected image; k is the number of iterations; and I is the set of rays at all projection angles.

[0124] Based on the above embodiments, such as Figure 1-6 As shown, Figure 1-6 This is a schematic diagram of a third process for an image processing method for computer-aided layered imaging provided in an embodiment of this application.

[0125] S101, Obtain known projection data p and scanning geometric parameters L of the computer-generated layered imaging of the object being detected.

[0126] Specifically, it can be used Figure 1-3 Known projection data p and scanning geometric parameters L of the computer-generated layered imaging of the object to be detected, obtained by scanning.

[0127] The geometric parameter set L includes the distance from the center of the X-ray source trajectory to the center of the stage, the distance from the center of the X-ray source trajectory to the center of the detector trajectory, the rotation radius of the X-ray source, the rotation radius of the detector, the rotation range of the X-ray source and the detector, the number of rotation divisions, the detector unit size, the number of detector units, and geometric correction parameters.

[0128] S102, Determine the initial estimated image f (0) The first 3D reconstructed image f is obtained by iteratively reconstructing the image based on known projection data and scanning geometric parameters. (k) After this step, a grayscale image of the interior of the plate-like object can be obtained. However, due to the aliasing of projection information, the reconstructed image suffers from severe interlayer artifacts, resulting in an unclear internal structure. Taking the acquisition of a set of actual circuit board data as an example, this set of data acquired 32 projections, which is insufficient. Figure 1-7The results of OS-SART iterative reconstruction of different layers of the circuit board are shown. Due to mutual interference between layers during acquisition and projection, the reconstructed circuit board structure is covered by a grayscale image, resulting in an unclear structure. Solder balls, pins, and circuit distribution have very low resolution in the reconstructed image, and there is serious interlayer information aliasing. Figure 1-8 The image is reconstructed for the BGA solder balls in the middle of the circuit board. Due to the interaction between layers, the size of the reconstructed solder balls is larger than the actual size, and it is also difficult to determine whether there are defects inside the solder balls.

[0129] S103, based on the current image layer division parameters, determine the upper image layer (1~m), the lower image layer (m+t+1)~M, and the middle image layer from (m+1) to (m+t).

[0130] It should be noted that in Figure 1-6 In the example shown, m+1 is equivalent to the current image layer partitioning parameter in the example above.

[0131] S104, using the above scanning geometric parameters, perform forward projection on the upper image layer (1~m) and the lower image layer (m+t+1~M) to obtain the projection data proj_up of the upper image layer and the projection data proj_down of the lower image layer.

[0132] S105, based on the known projection data, the first preset weight factor, the second preset weight factor, the projection data of the upper image layer and the projection data of the lower image layer, determine the updated projection data.

[0133] The updated projection data is determined using the following formula:

[0134] p′=p-w1*proj_up-w2*proj_down

[0135] Where p′ is the updated projection data, p is the known projection data, proj_up is the projection data of the upper image layer, proj_down is the projection data of the lower image layer; w1 is the first preset weight factor, and w2 is the second preset weight factor.

[0136] S106, perform image reconstruction based on the updated projection data p′ to obtain the second 3D reconstructed image u. (k) .

[0137] The method of obtaining the second 3D reconstructed image based on the updated projection data p′ can refer to step S102, which involves iteratively reconstructing the image based on the known projection data and scanning geometric parameters to obtain the first 3D reconstructed image f. (k) The method will not be elaborated here.

[0138] S107, using u (k) Updating the estimated image f from layer (m+1) to layer (m+t) (k) From layer (m+1) to layer (m+t), the third 3D reconstructed image f is obtained. (k+1) .

[0139] After this step, the reconstructed images of layers (m+1) to (m+t) after reducing the influence of layers (1-m) and (m+t+1) to M can be obtained. Interlayer artifacts are effectively suppressed, and image quality is significantly improved. Figure 1-7 , Figure 1-8 Taking the circuit board as an example, after steps S103 to S107, the corresponding layer result diagram is as follows: Figure 1-9 , Figure 1-10 .contrast Figure 1-7 , Figure 1-9 After mid-correction, the interlayer aliasing phenomenon in the image was significantly improved, the structural information and internal gray values ​​of the image were gradually restored, the image quality was significantly improved, and the interlayer resolution was increased.

[0140] contrast Figure 1-7 , Figure 1-10 After correction, the image quality was significantly improved, the reconstructed solder ball size was closer to the actual solder ball size, and the defects in the solder ball were more clearly visible.

[0141] S108, Determine whether the value of m+t+1 is greater than m. down (The maximum number of layers in the aforementioned intermediate interval), if not satisfied, proceed to step S109, if satisfied, proceed to step S1110.

[0142] S109, let f (k) =f (k+1) Update m, m = m + t.

[0143] S110 outputs the reconstructed image after artifact suppression.

[0144] The iteration is terminated, and the reconstructed image f after artifact suppression is obtained and output. (k+1 ).

[0145] A first 3D reconstructed image is obtained by reconstructing the image based on known projection data and scanning geometric parameters. Based on the current image layer division parameters, the upper image layer, lower image layer, and middle image layer are determined. The upper and lower image layers of the first 3D reconstructed image are projected forward using the scanning geometric parameters to obtain the projection data of the upper and lower image layers, respectively. A second 3D reconstructed image is determined based on the known projection data, the first preset weight factor, the second preset weight factor, the projection data of the upper image layer, and the projection data of the lower image layer. The middle image layer of the first 3D reconstructed image is updated using the middle image layer of the second 3D reconstructed image. By correcting the projection data, the internal structure of the reconstructed image is restored, and the image quality and interlayer resolution are improved.

[0146] Based on the above method embodiments, this application also provides a computer-aided layered imaging system, such as... Figure 2 As shown, Figure 2 A schematic diagram of a computer layered imaging system provided in this application embodiment includes:

[0147] X-ray source, detector, controller, and processor;

[0148] The aforementioned controller is used to control the aforementioned radiation source and the aforementioned detector;

[0149] The aforementioned radiation source is used to emit X-rays;

[0150] The aforementioned detector is used to acquire X-ray images;

[0151] The processor is configured to: reconstruct a first three-dimensional reconstructed image of the detected object based on known projection data obtained by scanning the detected object using a layered imaging scanning device; wherein the first three-dimensional reconstructed image includes a preset number of image layers in a preset direction; perform forward projection on the upper image layer (within the upper layer range) and the lower image layer (within the lower layer range) to obtain projection data corresponding to the upper image layer and projection data corresponding to the lower image layer; and reconstruct a second three-dimensional reconstructed image of the detected object based on the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer. The second three-dimensional reconstructed image includes the preset number of image layers in the preset direction; the middle image layer of the first three-dimensional reconstructed image is updated using the middle image layer of the second three-dimensional reconstructed image to obtain the updated three-dimensional reconstructed image of the detected object; the middle image layer is an image layer with a layer number in the middle range, the middle range is an image layer range to be corrected for artifacts, the upper range, the middle range and the lower range are obtained by dividing the preset number of ranges, and the interlayer artifact information included in the second three-dimensional reconstructed image is less than the interlayer artifact information included in the first three-dimensional reconstructed image.

[0152] In one possible embodiment, the processor is further configured to:

[0153] Based on the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer, the updated projection data is obtained by reducing the proportion of the projection data corresponding to the upper image layer and / or reducing the proportion of the projection data corresponding to the lower image layer in the known projection data.

[0154] Based on the updated projection data, image reconstruction is performed to obtain the second three-dimensional reconstructed image.

[0155] In one possible embodiment, the processor is further configured to:

[0156] Based on the known projection data, the projection data corresponding to the upper image layer, the first preset weight factor of the projection data corresponding to the upper image layer, the projection data corresponding to the lower image layer, and the second preset weight factor of the projection data corresponding to the lower image layer, the projection data is calculated to obtain the updated projection data.

[0157] In one possible embodiment, the processor is further configured to:

[0158] The updated projection data is determined using the following formula:

[0159] p′=p-w1*proj_up-w2*proj_down

[0160] Where p′ is the updated projection data, p is the known projection data, proj_up is the projection data corresponding to the upper image layer, proj_down is the projection data corresponding to the lower image layer; w1 is the first preset weight factor, and w2 is the second preset weight factor.

[0161] In one possible embodiment, the processor is further configured to:

[0162] If the upper limit of the middle interval where the aforementioned middle image layer is located is less than the preset upper limit of the middle layer, the interval ranges of the aforementioned upper interval, the aforementioned middle interval, and the aforementioned lower interval are updated according to the preset step size, and based on the updated interval ranges of the aforementioned upper interval, the aforementioned middle interval, and the aforementioned lower interval, the execution step is returned: the upper image layer whose layer number is in the upper interval and the lower image layer whose layer number is in the lower interval are respectively projected forward to obtain the projection data corresponding to the aforementioned upper image layer and the projection data corresponding to the aforementioned lower image layer;

[0163] Until the upper limit of the updated middle layer interval is greater than or equal to the preset upper limit of the middle layer, the updated 3D reconstructed image is taken as the final 3D reconstructed image of the detected object.

[0164] In one possible embodiment, the processor is further configured to:

[0165] Based on the current image layer segmentation parameters and preset step size, the image layers are divided into a first interval image layer, a second interval image layer, and a third interval image layer; wherein, the first interval image layer is located above the second interval image layer, and the third interval image layer is located below the second interval image layer.

[0166] The first interval image layer and the third interval image layer are projected forward respectively to obtain the projection data corresponding to the first interval image layer and the projection data corresponding to the third interval image layer.

[0167] Based on the projection data corresponding to the first interval image layer and the projection data corresponding to the third interval image layer, the third three-dimensional reconstructed image of the detected object is reconstructed.

[0168] Using the second interval image layer of the third 3D reconstructed image, the middle layer image layer of the first 3D reconstructed image is updated to obtain the fourth 3D reconstructed image;

[0169] If the current image layer partitioning parameter is less than the maximum number of layers in the above-mentioned intermediate interval, update the above-mentioned first 3D reconstructed image to the above-mentioned fourth 3D reconstructed image and increase the value of the image layer partitioning parameter; return to the execution step: based on the current image layer partitioning parameter and the preset step size, partition the first interval image layer, the second interval image layer and the third interval image layer;

[0170] If the current image layer division parameters are not less than the maximum number of layers in the above-mentioned middle layer interval, the above-mentioned fourth three-dimensional reconstructed image is used as the updated three-dimensional reconstructed image of the above-mentioned detection object.

[0171] In one possible embodiment, the processor described above is specifically used for:

[0172] Acquire known projection data and scanning geometric parameters obtained by the layered imaging scanning device from scanning the object to be detected;

[0173] Obtain the current reconstructed image; wherein the initial value of the current reconstructed image is a preset image;

[0174] Based on the above scanning geometric parameters, the first projection data of the current reconstructed image in the forward projection direction is determined;

[0175] If the difference between the known projection data and the first projection data is not less than a preset difference threshold, or if the difference between the known projection data and the first projection data is not less than a preset difference threshold and the preset number of iterations has not been reached, the current reconstructed image is updated, and the execution step is returned: Determine the first projection data of the current reconstructed image in the forward projection direction based on the above scanning geometric parameters.

[0176] If the difference between the known projection data and the first projection data is less than a preset difference threshold, or if the difference between the known projection data and the first projection data is less than a preset difference threshold and a preset number of iterations has been reached, the current reconstructed image is used as the first 3D reconstructed image.

[0177] Regarding the system in the above embodiments, the specific ways in which each module performs operations have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0178] This application also provides an electronic device, such as... Figure 3 As shown, it includes:

[0179] Memory 301 is used to store computer programs;

[0180] When processor 302 executes a program stored in memory 301, it performs the following steps:

[0181] Based on the known projection data obtained by scanning the object by the layered imaging scanning device, a first three-dimensional reconstructed image of the object is reconstructed; wherein the first three-dimensional reconstructed image includes a preset number of image layers in a preset direction;

[0182] Forward projection is performed on the upper image layer in the upper layer range and the lower image layer in the lower layer range to obtain the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer.

[0183] Based on the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer, a second three-dimensional reconstructed image of the detected object is obtained; wherein, the second three-dimensional reconstructed image includes the preset number of image layers in the preset direction.

[0184] Using the middle layer of the second 3D reconstructed image, the middle layer of the first 3D reconstructed image is updated to obtain the updated 3D reconstructed image of the detected object; wherein, the middle layer is an image layer with a layer number in the middle range, the middle range is an image layer range to be corrected for artifacts, and the upper range, the middle range and the lower range are obtained by dividing the preset number of ranges. The interlayer artifact information included in the second 3D reconstructed image is less than the interlayer artifact information included in the first 3D reconstructed image.

[0185] Furthermore, the aforementioned electronic device may also include a communication bus and / or a communication interface, with the processor 302, communication interface, and memory 301 communicating with each other via the communication bus.

[0186] The communication bus mentioned in the above electronic devices can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used to represent it in the diagram, but this does not mean that there is only one bus or one type of bus.

[0187] The communication interface is used for communication between the aforementioned electronic devices and other devices.

[0188] The memory may include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0189] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0190] In another embodiment provided in this application, a computer-readable storage medium is also provided, which stores a computer program that, when executed by a processor, implements the steps of any of the above-described image processing methods for computer-aided layered imaging.

[0191] In another embodiment provided in this application, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to perform any of the image processing methods for computer-aided layered imaging described in the above embodiments.

[0192] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or other media (e.g., solid state disk (SSD)).

[0193] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0194] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the embodiments of systems, electronic devices, computer-readable storage media, and computer program products are basically similar to the method embodiments, and therefore the descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0195] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. An image processing method for computer-aided layered imaging, characterized in that, The method includes: Based on the known projection data obtained by scanning the object of detection using a layered imaging scanning device, a first three-dimensional reconstructed image of the object of detection is reconstructed; wherein, the first three-dimensional reconstructed image includes a preset number of image layers in a preset direction; Forward projection is performed on the upper image layer (which is in the upper layer range) and the lower image layer (which is in the lower layer range) to obtain the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer. Based on the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer, a second three-dimensional reconstructed image of the detected object is reconstructed; wherein, the second three-dimensional reconstructed image includes the preset number of image layers in the preset direction; The middle layer of the first 3D reconstructed image is updated using the middle layer of the second 3D reconstructed image to obtain an updated 3D reconstructed image of the detected object. The updated 3D reconstructed image of the detected object is obtained by replacing the middle layer of the first 3D reconstructed image with the middle layer of the second 3D reconstructed image. The middle layer is an image layer with a layer number in the middle range, and the middle range is an image layer range to be corrected for artifacts. The upper range, the middle range, and the lower range are obtained by dividing the preset number of ranges. The interlayer artifact information included in the second 3D reconstructed image is less than the interlayer artifact information included in the first 3D reconstructed image.

2. The method according to claim 1, characterized in that, The process of reconstructing a second three-dimensional reconstructed image of the detected object based on the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer includes: Based on the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer, the updated projection data is obtained by reducing the proportion of the projection data component corresponding to the upper image layer and / or reducing the proportion of the projection data component corresponding to the lower image layer in the known projection data. Based on the updated projection data, image reconstruction is performed to obtain the second three-dimensional reconstructed image.

3. The method according to claim 2, characterized in that, The updated projection data, obtained by determining the proportion of the projection data component corresponding to the upper image layer and / or the proportion of the projection data component corresponding to the lower image layer in the known projection data based on the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer, includes: Based on the known projection data, the projection data corresponding to the upper image layer, the first preset weight factor of the projection data corresponding to the upper image layer, the projection data corresponding to the lower image layer, and the second preset weight factor of the projection data corresponding to the lower image layer, the projection data is calculated to obtain the updated projection data.

4. The method according to claim 3, characterized in that, The step of calculating the updated projection data based on the known projection data, the projection data corresponding to the upper image layer, a first preset weighting factor for the projection data corresponding to the upper image layer, the projection data corresponding to the lower image layer, and a second preset weighting factor for the projection data corresponding to the lower image layer, includes: The updated projection data is determined using the following formula: ； in, For the updated projection data, For the known projection data, This refers to the projection data corresponding to the upper image layer. This refers to the projection data corresponding to the lower image layer; The first preset weighting factor, This is the second preset weighting factor.

5. The method according to claim 1, characterized in that, The step of updating the intermediate image layer of the first 3D reconstructed image using the intermediate image layer of the second 3D reconstructed image to obtain the updated 3D reconstructed image of the detected object includes: If the upper limit of the middle interval where the middle image layer is located is less than the preset upper limit of the middle layer, the interval ranges of the upper interval, the middle interval and the lower interval are updated according to the preset step size, and based on the updated interval ranges of the upper interval, the middle interval and the lower interval, the execution step is returned: the upper image layer whose layer number is in the upper interval and the lower image layer whose layer number is in the lower interval are respectively forward projected to obtain the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer; Until the upper limit of the updated middle layer interval is greater than or equal to the preset middle layer upper limit, the updated 3D reconstructed image is taken as the final 3D reconstructed image of the detected object.

6. The method according to claim 1, characterized in that, The method of reconstructing a first three-dimensional reconstructed image of the detected object based on known projection data obtained by scanning the detected object using a layered imaging scanning device includes: Acquire known projection data and scanning geometric parameters obtained by the layered imaging scanning device from scanning the object to be detected; Obtain the current reconstructed image; where the current reconstructed image in the initial case is a preset image; The first projection data of the current reconstructed image in the forward projection direction is determined based on the scanning geometric parameters; If the difference between the known projection data and the first projection data is not less than a preset difference threshold, or if the difference between the known projection data and the first projection data is not less than a preset difference threshold and the preset number of iterations has not been reached, the current reconstructed image is updated, and the execution step is returned: determine the first projection data of the current reconstructed image in the forward projection direction based on the scanning geometric parameters; If the difference between the known projection data and the first projection data is less than a preset difference threshold, or if the difference between the known projection data and the first projection data is less than a preset difference threshold and a preset number of iterations has been reached, the current reconstructed image is used as the first 3D reconstructed image.

7. A computer-aided layered imaging system, characterized in that, include: X-ray source, detector, controller, and processor; The controller is used to control the radiation source and the detector; The radiation source is used to emit X-rays; The detector is used to acquire X-ray images; The processor is configured to: reconstruct a first three-dimensional reconstructed image of the detected object based on known projection data obtained by scanning the detected object using a layered imaging scanning device; wherein the first three-dimensional reconstructed image includes a preset number of image layers in a preset direction; perform forward projection on the upper image layer (within the upper layer range) and the lower image layer (within the lower layer range) to obtain projection data corresponding to the upper image layer and projection data corresponding to the lower image layer; and reconstruct a second three-dimensional reconstructed image of the detected object based on the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer; wherein the second three-dimensional reconstructed image includes the preset number of image layers in the preset direction. The number of image layers; using the middle image layer of the second 3D reconstructed image, the middle image layer of the first 3D reconstructed image is updated to obtain the updated 3D reconstructed image of the detected object; wherein, the middle image layer is an image layer with a layer number in the middle range, the middle range is the image layer range to be corrected for artifacts, the upper range, the middle range and the lower range are obtained by dividing the preset number of ranges, and the interlayer artifact information included in the second 3D reconstructed image is less than the interlayer artifact information included in the first 3D reconstructed image.

8. The system according to claim 7, characterized in that, The processor is also used for: Based on the projection data corresponding to the upper image layer and the projection data corresponding to the lower image layer, the updated projection data is obtained by reducing the proportion of the projection data component corresponding to the upper image layer and / or reducing the proportion of the projection data component corresponding to the lower image layer in the known projection data. Based on the updated projection data, image reconstruction is performed to obtain the second three-dimensional reconstructed image.

9. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor, when executing a program stored in memory, implements the method of any one of claims 1-6.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method described in any one of claims 1-6.

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