Digital imaging method, system and equipment based on ray filtration and medium

Abstract

The invention relates to a digital imaging method, system and device based on ray filtration and a medium. The method comprises the following steps: acquiring hardening correction parameters of X-rays penetrating through a scanned object based on X-ray energy spectrums of aluminum sheets with different thicknesses; establishing a mapping relation between the equivalent water thickness and the aluminum sheet thickness based on an attenuation value of an X-ray scanning image in combination with the hardening correction parameter; and extracting human body area image information in a business scanning image, obtaining an equivalent water thickness of the human body area image in combination with the hardening correction parameter, determining a target aluminum thickness according to a mapping relationship between the equivalent water thickness and the aluminum sheet thickness, and compensating the equivalent water thickness of a human body during scanning according to the target aluminum thickness. The thickness of the filtering aluminum sheet can be dynamically matched, the imaging gray difference between human tissues is balanced, the image accuracy and visibility are improved, and the problems of insufficient exposure and overexposure are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of digital imaging, and in particular to a digital imaging method, system, device and medium based on ray filtering. BACKGROUND

[0002] Digital X-ray radiography system (DR) technology is a kind of digital imaging technology developed on the basis of traditional X-ray photography. Generally speaking, conventional X-ray film is the simplest, most economical and fastest and effective examination method for evaluating normal spine or traumatic spinal lesions, which can provide complete display of bone morphology in weight-bearing position in standing position. Ideal orthopedic imaging examination should be full spine imaging in weight-bearing position. However, at present, the traditional X-ray equipment cannot complete the full spine photography at one time due to the limited imaging area, and can only be segmented and photographed to obtain the full length image by software splicing. This splicing image method not only is time-consuming and laborious, but also causes splicing error. To solve this problem, full-width DR is generated. Full-width DR can obtain full spine or full lower limb image by one-time exposure imaging, without the need for splicing, avoiding the splicing problem caused by segmented shooting, providing more intuitive and accurate image information for clinical diagnosis, and avoiding multiple shooting of patients and low radiation exposure.

[0003] However, since the full-width DR is one-time exposure imaging and the thickness of the upper and lower parts of the human body is uneven, the image has the problems of underexposure and overexposure. The existing technology only performs post-processing on the full-width DR imaging at the software algorithm level, such as improving the uniformity and contrast of the image by gamma correction and stretching processing algorithm, but the effect improvement is limited. Because the difference in thickness and density of the structure of each part of the human body leads to a large difference in gray value between different parts of the image, therefore, only through the algorithm cannot fundamentally solve the problem of gray difference between different parts.

[0004] In summary, the existing full-width DR imaging technology has the problems of underexposure and overexposure, resulting in low accuracy and visibility of the full-width image. SUMMARY

[0005] The present application provides a digital imaging method, system, device and medium based on ray filtering to solve the problem of low accuracy and visibility of the full-width image caused by underexposure and overexposure in the existing technology.

[0006] According to an aspect of the embodiments of the present application, the present application provides a digital imaging method based on ray filtering, an aluminum filter is additionally arranged in an X-ray scanning device, the method comprising: performing X-ray spectrum fitting based on X-ray images of aluminum filters with different thicknesses, obtaining an X-ray spectrum, and obtaining a hardening correction parameter of X-rays passing through a scanning object according to the X-ray spectrum; calculating a first equivalent water thickness of the aluminum filter based on an attenuation value of a pre-scan image and the hardening correction parameter, establishing a mapping relationship between the equivalent water thickness and the aluminum filter thickness according to the first equivalent water thickness; extracting human region image information based on a business scan image, and obtaining a second equivalent water thickness of the human region image based on the hardening correction parameter; determining a target aluminum thickness of the additional filter according to the second equivalent water thickness based on the mapping relationship between the equivalent water thickness and the aluminum filter thickness, and compensating the equivalent water thickness of the human body during scanning according to the target aluminum thickness.

[0007] Optionally, the X-ray spectrum fitting based on the X-ray images of the aluminum filters with different thicknesses, the obtaining of the X-ray spectrum, and the obtaining of the hardening correction parameter of the X-rays passing through the scanning object comprise: sequentially imaging aluminum filters with different thicknesses based on an X-ray imaging device to obtain an X-ray image sequence containing aluminum filter attenuation information; obtaining average gray values of the X-ray image sequence to establish a linear relationship between image gray values and transmission intensity, and constructing a transmission intensity model based on energy integration according to the linear relationship; taking a minimum error sum of squares of a calculated value of the transmission intensity model and an actual transmission intensity as an objective function to calculate the X-ray spectrum; and simulating and calculating an attenuation process of X-rays passing through a substance based on the X-ray spectrum through the transmission intensity model to obtain the hardening correction parameter for attenuation compensation of the X-ray hardening effect.

[0008] Optionally, the calculation of the first equivalent water thickness of the aluminum filter based on the attenuation value of the pre-scan image and the hardening correction parameter comprises: obtaining an air scan image and a human body scan image under X-rays, correcting the air scan image and the human body scan image by a detector respectively; calculating a ratio of the corrected air scan image and the human body scan image to obtain a first attenuation value of a scan image; performing data preprocessing on the first attenuation value to obtain a linearized second attenuation value; and calculating the first equivalent water thickness of the aluminum filter through a correction function according to the second attenuation value and the hardening correction parameter.

[0009] Optionally, the establishment of the mapping relationship between the equivalent water thickness and the aluminum filter thickness according to the first equivalent water thickness comprises: fitting a corresponding relationship curve of the equivalent water thickness and the aluminum filter thickness based on the first equivalent water thickness by using a polynomial high-order fitting model; and constructing a relationship function representing the mapping relationship between the aluminum filter thickness and the equivalent water thickness according to a fitting result.

[0010] Optionally, the second equivalent water thickness of the human body region image is obtained based on the image segmentation algorithm for human body region identification of the business scan image under X-ray, and target region pixels are extracted; a target attenuation value of the business scan image is obtained based on the target region pixels; the equivalent water thickness of each pixel in the human body region image is calculated by the correction function based on the target attenuation value of the business scan image and the hardening correction parameter; the corresponding equivalent water thickness is counted based on the pixel statistical characteristics of the human body region image, and the overall equivalent water thickness of the human body region image is obtained as the second equivalent water thickness.

[0011] Optionally, the target attenuation value of the business scan image is obtained based on the target region pixels, including: a third attenuation value of the business scan image is obtained based on the ratio of the target region pixels to the air scan image under X-ray; the third attenuation value is preprocessed to obtain the target attenuation value of the business scan image after linearization.

[0012] Optionally, the target aluminum thickness of additional filtering is determined according to the second equivalent water thickness based on the mapping relationship between the equivalent water thickness and the aluminum sheet thickness, and the equivalent water thickness of the human body is compensated during scanning according to the target aluminum thickness, including: the target equivalent water thickness of the human body region is determined based on the X-ray target imaging requirement, and the equivalent water thickness compensation amount is obtained according to the difference between the second equivalent water thickness and the target equivalent water thickness; the target aluminum thickness is obtained by calculating the relationship function based on the mapping relationship between the equivalent water thickness and the aluminum sheet thickness according to the equivalent water thickness compensation amount; the equivalent water thickness of the human body is compensated during scanning according to the target aluminum thickness.

[0013] According to another aspect of the embodiments of the present application, the present application provides a digital imaging system based on ray filtration, which comprises: an X-ray spectrum module, configured to perform X-ray spectrum fitting based on X-ray images of aluminum sheets with different thicknesses, to obtain an X-ray spectrum, and to obtain a hardening correction parameter of X-ray penetration through a scanning object according to the X-ray spectrum; an aluminum thickness mapping module, configured to calculate a first equivalent water thickness of the aluminum sheet based on an attenuation value of a scanning image under X-rays, in combination with the hardening correction parameter, and to establish a mapping relationship between the equivalent water thickness and the aluminum sheet thickness according to the first equivalent water thickness; a human body image analysis module, configured to extract human body region image information based on a service scanning image, and to obtain a second equivalent water thickness of the human body region image in combination with the hardening correction parameter; and an image gray scale compensation module, configured to determine a target aluminum thickness of additional filtration in an X-ray scanning device according to the second equivalent water thickness based on the mapping relationship between the equivalent water thickness and the aluminum sheet thickness, and to compensate for the equivalent water thickness of the human body during scanning according to the target aluminum thickness.

[0014] According to another aspect of the embodiments of the present application, the present application provides a digital radiography device, comprising an X-ray scanning device, a filtration aluminum sheet, a detector, and a master control module, wherein the X-ray scanning device emits X-rays and scans a human body through the filtration aluminum sheet, the detector performs imaging based on X-rays and transmits imaging data to the master control module, and when the digital radiography device is running, the master control module executes machine readable instructions to perform the steps of the digital imaging method based on ray filtration.

[0015] According to another aspect of the embodiments of the present application, the present application provides a computer readable storage medium having a non-volatile program code executable by a processor, wherein the computer readable storage medium stores a computer program, and the computer program performs the steps of the digital imaging method based on ray filtration when executed by the master control module.

[0016] The above technical solutions provided by the embodiments of the present application have the following advantages compared with related art: The present application can be applied to the scene of X-ray photography of a digital radiography device. By adding a filtration aluminum sheet, the present application can block radiation doses of different degrees for different parts of the human body, so that the radiation doses received by different parts of the human body are different, thereby avoiding the problem of dose mismatch. By performing hardening correction processing and equivalent water thickness calculation on the filtered full-width DR scanning image, the matching accuracy of the high-matching filtration aluminum sheet thickness is improved, so that the gray scale values of the filtered scanning image are kept within a certain range, the gray scale balance of the full-width image is ensured, the problems of overexposure or underexposure of the full-width image are overcome, the full-width image accuracy and visibility are further improved, and high-quality image output is realized. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the accompanying drawings needed to be used in the embodiments or the related art description will be briefly introduced. Obviously, for those of ordinary skill in the art, without paying creative labor, other drawings can also be obtained from these drawings.

[0019] Figure 1 An optional hardware environment schematic diagram of a ray filtering based digital imaging method according to an embodiment of the present application is provided. Figure 2 An optional flowchart of a ray filtering based digital imaging method according to an embodiment of the present application is provided. Figure 3 An optional hardening correction parameter calculation flowchart according to an embodiment of the present application is provided. Figure 4 An optional human body image equivalent water thickness calculation flowchart according to an embodiment of the present application is provided. Figure 5 An optional traditional unfiltered human body image schematic diagram according to an embodiment of the present application is provided. Figure 6 An optional additional filtered human body image schematic diagram according to an embodiment of the present application is provided. Figure 7 An optional structure diagram of a ray filtering based digital imaging system according to an embodiment of the present application is provided. Figure 8 An optional structure schematic diagram of a digital radiography device according to an embodiment of the present application is provided. Figure 9 Another optional structure schematic diagram of a digital radiography device according to an embodiment of the present application is provided. Figure 10 An optional additional filtered aluminum sheet three-dimensional structure schematic diagram according to an embodiment of the present application is provided. DETAILED DESCRIPTION

[0020] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without paying creative labor are within the scope of protection of the present application.

[0021] To address the problems mentioned in the background art, according to one aspect of the embodiments of this application, an embodiment of a digital imaging method based on ray filtering is provided.

[0022] like Figure 1 As shown, the above-described digital imaging method based on X-ray filtering can be applied to, for example... Figure 1 The hardware environment shown is described. The system architecture 100 of the hardware environment includes a terminal device 101 and a server 103. The server 103 is connected to the terminal 101 via a network and can be used to provide services to the terminal or clients installed on the terminal. A database 105 can be set up on the server or independently of the server to provide data storage services to the server 103. The network can include various connection types, such as wired, wireless communication links, or fiber optic cables, etc.

[0023] Users can use terminal device 101 to interact with server 103 via a network to receive or send messages, etc. Terminal device 101 may be installed with program instructions for digital radiography equipment filtering methods, such as X-ray scanning and image analysis. Terminal device 101 can be various electronic devices with a display screen and web browsing support, including but not limited to smartphones, tablets, e-book readers, laptops, and desktop computers. Server 103 can be a server providing various services, such as a backend server supporting the pages displayed on terminal device 101.

[0024] It should be noted that the X-ray filtering-based digital imaging method provided in this application is generally executed by a server and / or terminal device, and correspondingly, the X-ray filtering-based digital imaging system is generally located in the server / terminal device. Furthermore, it should be understood that... Figure 1 The number of terminal devices, networks, and servers shown is merely illustrative. Depending on implementation needs, any number of terminal devices, networks, and servers can be included.

[0025] like Figure 2 As shown, Figure 2 A flowchart of a digital imaging method based on X-ray filtering provided in an embodiment of the present invention. Taking the execution of the digital imaging method based on X-ray filtering by a server as an example, the digital imaging method based on X-ray filtering includes: attaching a filter aluminum sheet to an X-ray scanning device, the method including the following steps: Step S202: X-ray energy spectrum fitting is performed based on X-ray images of aluminum sheets of different thicknesses to obtain X-ray energy spectra, and hardening correction parameters for X-rays passing through the scanned object are obtained based on the X-ray energy spectra.

[0026] In the embodiment, an aluminum filter is added to the X-ray scanning device to reduce the proportion of soft X-rays, increase the average energy of X-rays, enhance the penetration ability, and make the effective X-ray energy more concentrated while reducing the useless soft X-rays, thereby reducing the patient exposure dose under the premise of ensuring the image quality.

[0027] In the embodiment, the X-ray spectrum is fitted through the X-ray image data of the aluminum sheets with different thicknesses, and the correction parameter of the X-ray hardening effect is calculated to overcome the problem of image gray scale distortion.

[0028] In step S204, the first equivalent water thickness of the aluminum sheet is calculated based on the attenuation value of the X-ray down-scan image and the hardening correction parameter, and the mapping relationship between the equivalent water thickness and the aluminum sheet thickness is established according to the first equivalent water thickness.

[0029] In the embodiment, the equivalent water thickness refers to the equivalent thickness of water converted from the attenuation effect of human tissue, and the first equivalent water thickness is calculated through the hardening correction parameter and the attenuation value, so that the complex absorption characteristics of human tissue are simplified into a single parameter for subsequent dynamic compensation. The mapping relationship between the equivalent water thickness and the aluminum sheet thickness is established by correlating the aluminum sheet thickness and the attenuation characteristics of human tissue, and the corresponding aluminum sheet thickness reference is provided for the equivalent water thickness of different human body regions through the mapping relationship, thereby laying a foundation for dynamic filtering.

[0030] In step S206, the image information of the human body region is extracted based on the service scanning image, and the second equivalent water thickness of the human body region image is obtained in combination with the hardening correction parameter.

[0031] In the embodiment, in the actual scanning, the image information of the human body region is extracted, and the second equivalent water thickness is calculated in combination with the hardening correction parameter, so as to convert the personalized tissue thickness of the patient into a quantifiable compensation parameter.

[0032] In step S208, the target aluminum thickness of the additional filtering is determined according to the second equivalent water thickness based on the mapping relationship between the equivalent water thickness and the aluminum sheet thickness, and the equivalent water thickness of the human body is compensated according to the target aluminum thickness during scanning.

[0033] In the embodiment, the target aluminum thickness is determined according to the mapping relationship between the equivalent water thickness and the aluminum sheet thickness, so as to dynamically adjust the filter sheet during scanning and compensate for the equivalent water thickness difference of different regions of the human body.

[0034] In an optional embodiment, the above step S202 specifically includes: Figure 3 As shown in FIG. 2, the above step S202 specifically includes: In step S2021, the X-ray imaging device sequentially images the aluminum sheets with different thicknesses to obtain an X-ray image sequence containing aluminum sheet attenuation information. Step S2022, obtaining the average gray value of the X-ray image sequence to establish a linear relationship between image gray and transmission intensity, and constructing a transmission intensity model based on energy integration according to the linear relationship; Step S2023, taking the minimum error sum of squares of the calculated value of the transmission intensity model and the actual transmission intensity as the objective function, and calculating the X-ray spectrum; Step S2024, based on the X-ray spectrum, simulating the attenuation process of X-rays passing through the substance through the transmission intensity model to obtain the hardening correction parameter for attenuation compensation of the X-ray hardening effect.

[0035] In some embodiments, the hardening correction parameter can be obtained by Monte Carlo simulation, and the specific steps are as follows: (1) Using an X-ray imaging device, under the same X-ray source condition, collecting X-ray images of different thicknesses d1, d2,..., d n (d i i represents the thickness of the i-th aluminum sample), to obtain an X-ray image sequence containing attenuation information of aluminum sheets of different thicknesses, and the pixel value in the image reflects the attenuation degree of X-rays passing through the corresponding thickness aluminum sheet; (2) Based on the X-ray image sequence, the average gray value G(d i ) (representing the image average gray value when the thickness is d i ) is extracted, and a linear relationship between gray and transmission intensity is established through a calibration experiment: G(di)=K*I(d i )+b, wherein k and b are calibration coefficients, and I(d i ) is the total X-ray transmission intensity corresponding to the thickness d i ; (3) Based on the physical nature of polychromatic X-ray attenuation, a model in the form of energy integration is used to describe the transmission intensity, and an attenuation coefficient calculation model is constructed: (1); wherein E is the photon energy, S(E) is the incident X-ray spectrum to be fitted, is the attenuation coefficient of aluminum to the photon of energy E; After parameterizing S(E), taking the error sum of squares of the measured transmission intensity and the model calculated value as the objective function: (2); wherein is the measured transmission intensity when the thickness is d i , is the model calculated transmission intensity, and the parameters can be iteratively optimized by Levenberg-Marquardt algorithm and the like to minimize the error to back-propagate S(E). That is, the X-ray spectrum is obtained; (4) According to the obtained X-ray spectrum S(E), the attenuation process of X-rays passing through the material is simulated by combining the attenuation coefficient calculation model (formula 1) of the interaction between X-rays and the material (considering the difference in attenuation of photons of different energies due to photoelectric effect, Compton scattering, etc.). According to the S(E) spectrum data obtained above, the attenuation ratio is calculated and substituted into the following formula: (3); Based on the above formula (3), the hardening correction parameters and are calculated, collectively referred to as HardenParas. The parameters contain attenuation characteristic correction information caused by X-ray hardening effect, which is used to compensate for the hardening effect in subsequent equivalent water thickness calculation.

[0036] In this embodiment, X-ray hardening refers to the phenomenon that low-energy photons are preferentially absorbed, resulting in an increase in the average energy of the remaining rays, which can cause image gray scale distortion. By fitting the X-ray spectrum from the X-ray image data of aluminum sheets of different thicknesses, the correction parameters of the X-ray hardening effect are calculated, thereby improving the correction accuracy and adapting to the differences in tissue thickness of different patients, avoiding the limitations of traditional algorithms.

[0037] In some embodiments, aluminum is a uniform single material with known and stable X-ray attenuation characteristics (mass attenuation coefficient) and no composition of human tissues (such as bone, muscle, fat); different thicknesses of aluminum sheets can simulate continuous attenuation scenarios from thin to thick, covering the attenuation range of different parts of the human body (such as thin neck spine and thick waist spine) in digital radiography device scanning, thereby avoiding the interference of human tissue composition fluctuations on attenuation information and providing pure and quantifiable raw data for subsequent spectrum fitting.

[0038] Further, a linear relationship between gray scale and transmission intensity is established by the average gray scale value of the aluminum sheet image, and an energy integral is constructed to build a transmission intensity model, the purpose of which is to realize accurate conversion of signals and physics. The gray scale value output by the detector of the digital radiography device is the digitization result of the electrical signal, which is not naturally linear with the actual X-ray transmission intensity (physical quantity) passing through the material. Through the known attenuation characteristics of the aluminum sheet (the mass attenuation coefficient of aluminum is known), the linear mapping of gray scale value and transmission intensity can be established according to the attenuation law to convert qualitative image signals into quantitative physical intensity, providing a data basis for subsequent spectrum calculation and systematic errors caused by single-energy model calculation of transmission intensity.

[0039] In an optional embodiment, in the above step S204, based on the attenuation value of the X-ray scan image, the first equivalent water thickness of the aluminum sheet is calculated by combining the hardening correction parameters, specifically including: An air scan image and a human body scan image under X-ray are acquired, and a detector is used to correct the air scan image and the human body scan image respectively; A ratio of the corrected air scan image and the human body scan image is calculated to obtain a first attenuation value of a scan image; The first attenuation value is pre-processed to obtain a linearized second attenuation value; The first equivalent water thickness of the aluminum sheet is calculated by a correction function according to the second attenuation value and the hardening correction parameter.

[0040] In some optional examples, an air image and a human body scan image under X-ray are acquired and are denoted as air_image and scan_image respectively, and are corrected by a detector to eliminate the influence of the detector offset. A ratio of the corrected air image and the human body scan image is calculated to obtain a relative attenuation coefficient (i.e. a first attenuation value), denoted as f1: f1=air_image / scan_image. Abnormal values in f1 are filtered: when the pixel gray value of the air image or the human body scan image is ≤0, the attenuation ratio of the corresponding position is set to 0 to avoid invalid values interfering with subsequent calculation, i.e. f1(air_image<=0)=0, f1(scan_image<=0)=0. The attenuation ratio f1 is logarithmically transformed to obtain linearized attenuation data: f1_log=log(f1) (i.e. a second attenuation value).

[0041] Further, according to the hardening correction parameter HardenParas, the negative logarithmic attenuation value (-f1_log) is converted into equivalent water thickness Y by a correction function (CalEquvalenThickness), and the formula is as follows: Y=CalEquvalenThickness(-f1_log,HardenParas)(4); Wherein, the specific calculation formula of CalEquvalenThickness is: Y=Proj / ( a Al - b Al *Proj)(5); Wherein, and Proj is equal to -f1_log.

[0042] In the embodiment, by air and human body scan map correction and ratio calculation, non-human factor interference such as detector noise and X-ray intensity fluctuation is eliminated, and it is ensured that the attenuation value only reflects human body tissue attenuation, so as to eliminate digital radiography device errors (such as detector noise and X-ray intensity fluctuation), because air is non-attenuating, the ratio can be normalized, and non-human factors are excluded. Linearization preprocessing of the first attenuation value avoids calculation deviation caused by nonlinear attenuation data; combined with hardening correction parameters, the hardening effect of X-rays passing through the material is directly offset, and the error caused by the hardening effect of X-rays passing through the material is avoided. Accurate first equivalent water thickness of the aluminum sheet is obtained, which provides reliable data support for subsequent equivalent water thickness and aluminum sheet thickness mapping relationship establishment and target aluminum thickness determination, and guarantees the accuracy of digital radiography device imaging compensation from the source, and overcomes the problem of uneven image exposure.

[0043] In an optional embodiment, in step S204, the mapping relationship between the equivalent water thickness and the aluminum sheet thickness is established according to the first equivalent water thickness, and specifically includes: Based on the first equivalent water thickness, a polynomial high-order fitting model is used to fit the corresponding relationship curve of the equivalent water thickness and the aluminum sheet thickness; According to the fitting result, a relationship function representing the mapping relationship between the aluminum sheet thickness and the equivalent water thickness is constructed.

[0044] In the embodiment, based on the above formula (5), combined with the hardening correction parameter, the geometric parameters of the aluminum sheet with different thicknesses are input, and the corresponding equivalent water thickness is calculated. Specifically: Suppose the aluminum sheet thickness is Y_Al, and the equivalent water thickness is X_Al. Through a plurality of groups of simulation (for example, Y_Al takes 1mm, 2mm…30mm), a {Y_Al, X_Al} data pair is obtained, a polynomial high-order fitting model is used to fit the corresponding relationship curve or mathematical model of the aluminum thickness and the equivalent water thickness, such as Y_Al=f(X_Al), and the mapping relationship between the aluminum sheet thickness and the equivalent water thickness is established. Wherein, the polynomial high-order fitting model is as follows: The m-order polynomial fitting model is constructed: (6); Wherein, is a polynomial coefficient, is a fitting error, and the polynomial coefficient is solved by using the least square method Matrix, the objective function is: (7).

[0045] In some examples, the equivalent water thickness of each position (row position) of the human body is obtained first, and then the equivalent water thickness of the aluminum plate with different thicknesses is obtained. It should be noted that, because the number of aluminum plates with different thicknesses selected is limited, in order to obtain more accurate calculation results, a limited number of aluminum plates with different thicknesses can be inserted into the equivalent water thickness of the human body at the row position, for example, 30 aluminum plates with different thicknesses are selected, the row position is 8696, and the 30 data are interpolated into the human body at the row position of 8696 to obtain the relationship between the equivalent water thickness and the thickness of the aluminum plate.

[0046] In the embodiment, the polynomial high-order fitting can fit the complex nonlinear correspondence between the equivalent water thickness and the thickness of the aluminum sheet, avoid the deviation of the low-order model which cannot match the actual physical relationship, and ensure the accuracy of the mapping relationship; the discrete first equivalent water thickness data are converted into a continuous relationship function, and the corresponding thickness of the aluminum sheet can be quickly and accurately calculated according to the second equivalent water thickness of any human body region, thereby providing direct calculation support for dynamic compensation; the fitting model can cover the whole range of the equivalent water thickness and the thickness of the aluminum sheet obtained by experiments, adapt to the thickness difference of different parts of the human body (such as the cervical spine, the lumbar spine and the lower limbs), ensure the universality of the compensation scheme, and solve the uneven exposure problem of different regions in the imaging of the digital radiography device.

[0047] In an optional embodiment, the method further comprises the following steps: Figure 4 As shown in FIG. 6, the step S206 specifically comprises the following steps: Step S2061, performing human body region recognition on the business scan image under X-ray based on an image segmentation algorithm, and extracting target region pixels; Step S2062, obtaining a target attenuation value of the business scan image based on the target region pixels; Step S2063, calculating the equivalent water thickness of each pixel in the human body region image based on the target attenuation value of the business scan image and the hardening correction parameter through the correction function; Step S2064, statistically analyzing the corresponding equivalent water thickness based on the pixel statistical features of the human body region image, obtaining the overall equivalent water thickness of the human body region image, and taking the overall equivalent water thickness as the second equivalent water thickness.

[0048] In an optional embodiment, an image segmentation algorithm (such as threshold segmentation or a deep learning segmentation model U-Net) is used to process the human body scan image under X-ray, recognize and extract the human body region (excluding background, equipment and other interference), and generate a binary mask body_mask. In the mask, the pixels corresponding to the human body tissue are 1, and the pixels corresponding to the non-human body region are 0.

[0049] Further, the body_mask is applied to the original X-ray image to extract the target region pixels of the human body region, and the target region pixels are substituted into the formula Y=Proj / (a Al - b Al The equivalent water thickness of each pixel in the human region is calculated by combining the hardening correction parameter HardenParas, and the overall equivalent water thickness X_body of the human region is obtained by statistical processing (such as mean value and median value) of the pixels in the region. X_body is taken as the second equivalent water thickness.

[0050] In this embodiment, the human target region pixels are extracted by image segmentation, and irrelevant region interference such as background and device edge is removed to accurately lock the calculation range and ensure that the equivalent water thickness calculation focuses only on human tissue, avoiding the influence of invalid data on the accuracy. The equivalent water thickness of each pixel is calculated in combination with the hardening correction parameter to offset the attenuation distortion caused by the hardening effect of X-rays, ensuring that the thickness data of a single pixel truly reflects the actual thickness of human tissue. The overall equivalent water thickness of the human region is obtained by statistical processing of the pixels, rather than isolated pixel values, which meets the needs of digital radiography devices for overall exposure compensation of different regions of the human body (such as a certain segment of the spine or a certain part of the lower limbs), and provides accurate and unified thickness basis for subsequent determination of the target aluminum thickness of the region.

[0051] In an optional embodiment, the above step S2062 specifically includes: obtaining a third attenuation value of the service scan image based on the ratio of the target region pixels to the air scan image under X-rays; performing data preprocessing on the third attenuation value to obtain a target attenuation value of the service scan image after linearization.

[0052] In this embodiment, the third attenuation value is the ratio of the target region pixels to the air scan image, and the background interference of the X-ray imaging system is removed through the ratio, that is, the detector inherent noise, X-ray source intensity fluctuation, and device optical path inherent attenuation are removed from the air scan image, which are non-human factor interference, ensuring that the third attenuation value only focuses on the attenuation effect of human tissue on X-rays, and completely reflects the actual attenuation characteristics of human tissue, providing accurate original data only related to human tissue for the second equivalent water thickness calculation.

[0053] Further, in view of the nonlinear characteristics of X-ray (multi-energy spectrum) attenuation, the nonlinear third attenuation value is converted into a target attenuation value that is linearly related to the required equivalent water thickness of human tissue through preprocessing such as hardening correction and linearization algorithm, thereby eliminating nonlinear deviation.

[0054] In the embodiment, the target attenuation value is obtained through linearization processing, a direct linear relationship between the attenuation value and the human tissue thickness is established, the problem of mismatch between the attenuation value and the thickness caused by nonlinearity is avoided, a linear basis is provided for accurately obtaining the second equivalent water thickness calculation, and the calculation accuracy of exposure compensation is further ensured.

[0055] In an optional embodiment, the step S208 specifically includes: determining a target equivalent water thickness of the human body region based on X-ray target imaging requirements, and obtaining an equivalent water thickness compensation amount according to a difference between the second equivalent water thickness and the target equivalent water thickness; calculating the relationship function according to the equivalent water thickness compensation amount based on the mapping relationship between the equivalent water thickness and the aluminum sheet thickness, to obtain the target aluminum thickness.

[0056] In the embodiment, the X-ray target imaging requirement can refer to a clinical imaging requirement of A-ray. Specifically, an ideal equivalent water thickness X of a human body region of interest (a target region of the human body) can be set according to a clinical imaging requirement, a radiation dose standard, and a tissue diagnosis requirement. The value comprehensively considers the mutual influence relationship between imaging clarity and radiation safety, and is used as a reference for subsequent calculation of filter compensation. For example, when high contrast is required, the ideal equivalent water thickness corresponds to a specific radiation dose attenuation, thereby limiting the excessively high dose to ensure image clarity.

[0057] Further, the additional filtered equivalent water thickness difference X_add (i.e., the equivalent water thickness compensation amount) is calculated according to the second equivalent water thickness, and the formula is X_add=X-X_body. X_add reflects the equivalent water thickness compensation amount required to make the human tissue equivalent water thickness reach the ideal value X, and realizes the quantization of the difference between the ideal equivalent water thickness X and the actual equivalent water thickness X_body.

[0058] Further, based on the mapping relationship between the equivalent water thickness and the aluminum sheet thickness, i.e., the formula Y_Al=f(X_Al), X_add is substituted into the f function, and the corresponding aluminum thickness Y_AL_add is calculated, Y_AL_add=f(X_add), to obtain the target aluminum thickness required by the additional filter, and realize the conversion of the equivalent water thickness compensation amount to the aluminum physical thickness.

[0059] In some examples, the hardening effect can cause abnormal gray scale or gray scale discontinuity at the edge of thick tissue, that is, the gray scale jumps at the junction of different thickness regions, thereby causing uneven exposure or insufficient exposure of different human tissues in the obtained X-ray image. As shown in Figure 5 Figure 5 ​The middle and lower sides are overexposed, the imaging is blackened, and the clinical diagnosis result is affected. In the embodiment, the attenuation deviation caused by the hardening effect in the region is quickly calculated through the target equivalent water thickness, and then it is determined how much thickness of the aluminum sheet needs to be added to compensate for the deviation, that is, the X-ray filtering adjustment is performed according to the thickness difference of different human tissues, and the gray uniformity of different thickness regions in the final image is ensured, as shown in Figure 6 Figure 6 By using the additional filtering device in the embodiment, the exposure of each part of the human body is uniform and clear.

[0060] In the embodiment, by setting the target equivalent water thickness of the clinical requirement, the difference between the actual thickness of the human body (the second equivalent water thickness) and the target value is converted into a specific equivalent water thickness compensation amount, and then relying on the mapping relationship, it is further converted into an executable target aluminum thickness, realizing the quantization and landing of the compensation amount. The target aluminum thickness is calculated based on the second equivalent water thickness of the specific region of the human body, and can be targeted to match the thickness difference of different parts, avoiding the one-size-fits-all compensation method, and then accurately solving the problem of overexposure or insufficient exposure caused by uneven thickness of different human body regions in the digital radiography device.

[0061] Among them, the thick region is optimized for penetration with an adaptive aluminum sheet, and the thin region avoids excessive filtering. The target aluminum thickness serves as a filtering parameter during scanning, which can balance the X-ray dose of different human body regions by adjusting the X-ray penetration intensity from the physical layer, and realize the root cause of the uneven imaging problem of the digital radiography device in one exposure.

[0062] In other embodiments, a plurality of groups of patient Y AL add data under different body types are collected, and a 3rd order polynomial fitting is used, as follows: Y AL=aX_{add}^3+bX_{add}^2+cX_{add}+d, wherein a, b, c, and d are fitting coefficients. The coefficients are optimized by the least square method to minimize the error between the fitting curve and the actual data, and a stable and general additional filtering thickness calculation model is obtained to adapt to the equivalent water thickness compensation needs of different human bodies.

[0063] According to another aspect of the embodiments of the present application, as Figure 7 As shown in the above-mentioned embodiment, the digital radiography device filtering method, the embodiment provides a digital imaging system based on ray filtering, and the system comprises: An X-ray spectrum module 701 is configured to perform X-ray spectrum fitting based on X-ray images of different thickness aluminum sheets, obtain an X-ray spectrum, and obtain an X-ray hardening correction parameter according to the X-ray spectrum. ​The aluminum thickness mapping module 703 is configured to calculate a first equivalent water thickness of the aluminum sheet based on the attenuation value of the X-ray subsurface image and the hardening correction parameter, and to establish a mapping relationship between the equivalent water thickness and the aluminum sheet thickness according to the first equivalent water thickness. The human body image analysis module 705 is configured to extract human body region image information based on the business subsurface image, and to obtain a second equivalent water thickness of the human body region image based on the hardening correction parameter. The image gray compensation module 707 is configured to determine a target aluminum thickness of additional filtering in the X-ray scanning device based on the mapping relationship between the equivalent water thickness and the aluminum sheet thickness, and to compensate the equivalent water thickness of the human body during scanning according to the target aluminum thickness.

[0064] In some optional embodiments, the X-ray energy spectrum module 701 specifically includes: a first acquisition unit configured to sequentially image aluminum sheets with different thicknesses by using an X-ray imaging device, and to acquire an X-ray image sequence containing aluminum sheet attenuation information; a relationship establishing unit configured to acquire average gray values of the X-ray image sequence, to establish a linear relationship between image gray and transmission intensity, and to construct a transmission intensity model based on energy integration according to the linear relationship; a first calculation unit configured to take the minimum error sum of squares of the calculated value of the transmission intensity model and the actual transmission intensity as an objective function, and to calculate the X-ray energy spectrum; and a second calculation unit configured to simulate and calculate the attenuation process of X-rays passing through a substance by using the transmission intensity model based on the X-ray energy spectrum, so as to obtain the hardening correction parameter for attenuation compensation of the X-ray hardening effect.

[0065] In some optional embodiments, the aluminum thickness mapping module 703 specifically includes: a correction unit configured to acquire an air subsurface image and a human body subsurface image under X-rays, and to correct the air subsurface image and the human body subsurface image by using a detector respectively; an attenuation value acquisition unit configured to calculate the ratio of the corrected air subsurface image and the human body subsurface image, so as to obtain a first attenuation value of the subsurface image; a preprocessing unit configured to perform data preprocessing on the first attenuation value, so as to obtain a linearized second attenuation value; and a third calculation unit configured to calculate the first equivalent water thickness of the aluminum sheet by using a correction function according to the second attenuation value and the hardening correction parameter.

[0066] In some optional embodiments, the aluminum thickness mapping module 703 specifically further includes: a fitting unit configured to fit a corresponding relationship curve between the equivalent water thickness and the aluminum sheet thickness by using a polynomial high-order fitting model based on the first equivalent water thickness; and a function establishing unit configured to construct a relationship function representing the mapping relationship between the aluminum sheet thickness and the equivalent water thickness according to the fitting result.

[0067] In some optional embodiments, the human body image analysis module 705 specifically comprises: a human body recognition unit, configured to recognize a human body region in a business scan image under X-rays based on an image segmentation algorithm, and extract a target region pixel; a target attenuation value acquisition unit, configured to acquire a target attenuation value of the business scan image based on the target region pixel; a fourth calculation unit, configured to calculate an equivalent water thickness of each pixel in a human body region image based on the target attenuation value of the business scan image and the hardening correction parameter through the correction function; and a statistical unit, configured to statistically analyze the corresponding equivalent water thickness based on a pixel statistical feature of the human body region image, acquire an overall equivalent water thickness of the human body region image, and take the overall equivalent water thickness as the second equivalent water thickness.

[0068] In some optional embodiments, the target attenuation value acquisition unit is specifically configured to: acquire a third attenuation value of the business scan image based on a ratio of the target region pixel to an air scan image under X-rays; and perform data preprocessing on the third attenuation value to acquire a target attenuation value of the business scan image after linearization.

[0069] In some optional embodiments, the image gray scale compensation module 707 specifically comprises: a compensation amount calculation unit, configured to determine a target equivalent water thickness of a human body region based on an X-ray target imaging requirement, and acquire an equivalent water thickness compensation amount based on a difference between the second equivalent water thickness and the target equivalent water thickness; a target aluminum thickness calculation unit, configured to acquire the target aluminum thickness based on a mapping relationship between the equivalent water thickness and the aluminum sheet thickness, and calculate the relationship function based on the equivalent water thickness compensation amount; and a compensation unit, configured to compensate the equivalent water thickness of the human body during scanning based on the target aluminum thickness.

[0070] It should be noted that the above modules and the examples and application scenarios implemented by the corresponding steps are the same as the above embodiments, but are not limited to the above disclosed content. It should be noted that the above modules as part of the system can run in the hardware environment as shown in Figure 1 The above system can be implemented by software or hardware.

[0071] It should be noted that the suffixes such as modules, components, and units used to represent elements in the above system do not have specific meanings by themselves, and can be mixedly used.

[0072] According to another aspect of the embodiments of the present application, the present application provides a digital radiography device, as shown in Figure 8As shown, including X-ray scanning device, filter aluminum sheet, detector and host module, the X-ray scanning device emits X-rays and scans the human body through the filter aluminum sheet, the detector images based on X-rays and transmits imaging data to the host module, when the digital radiography equipment runs, the host module executes machine readable instructions to perform the steps of the above-mentioned digital imaging method based on ray filtering.

[0073] In some possible embodiments, as Figure 9 As shown, the X-ray scanning device in the digital radiography equipment includes an X-ray source rack A1, a high-voltage generator A2, and a ball tube A4; the detector includes a detector rack A6, a detector A7, and an exposure area A8.

[0074] In this embodiment, by installing the hardware additional filter, according to the structure of the human body, different degrees of dose filter blocking are performed on each part, so that the dose received by each part of the patient is different, instead of the whole body being irradiated with the same dose before, thereby reducing the radiation dose received by the human body, avoiding the problem that the human body receives a high dose in thin tissue parts and a dose deficiency in thick tissue parts. Without developing a new image processing algorithm, the problem of poor uniformity of full-width DR images is fundamentally solved, by additional filtering, the image gray value obtained after irradiating the patient is maintained within a certain range, without extremely high and extremely low gray values, ensuring that the full-width image has no obvious overexposure or underexposure problem, avoiding the problem of over-bright or over-dark in the image, so that the overall light and dark of the image is more uniform.

[0075] In this embodiment, by the additional filtering digital radiography equipment, not only does the patient receive less dose radiation, but also the problems of non-uniform gray scale, poor overall uniformity of the image, and poor contrast in the full-width DR image are fundamentally solved, avoiding the problems of overexposure and underexposure, and realizing high-quality image output.

[0076] Specifically, as Figure 10 As shown, Figure 10 A three-dimensional structure diagram of the additional filter aluminum sheet A4, which can be installed on the X-ray source rack A1, supports fast installation and removal, and parameter adjustment.

[0077] Specifically, when scanning the patient (A5), the X-ray source rack A1, the high-voltage generator A2, and the ball tube A4 cooperate to emit X-rays, the X-rays are filtered by the additional filter aluminum sheet A4, the X-rays are detected by the detector A7 and imaged in the exposure area A8, and finally the imaging is sent to the host module for algorithm A9 to analyze and process the image.

[0078] The master module includes a memory, a processor, a communication bus and a communication interface. The memory and the processor communicate through the communication bus and the communication interface. The communication bus can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus can be divided into an address bus, a data bus, a control bus, etc.

[0079] The memory can include a Random Access Memory (RAM) and can also include a non-volatile memory, such as at least one disk memory. Optionally, the memory can also be at least one storage device located away from the aforementioned processor.

[0080] The processor described above can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc. It can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component.

[0081] According to another aspect of the embodiments of the present application, a computer medium having a non-volatile program code executable by a processor is also provided. The computer readable storage medium stores a computer program, which, when executed by the master module, performs the steps of the ray filtering-based digital imaging method.

[0082] Optionally, the specific examples in the embodiments can refer to the examples described in the above embodiments, which will not be described here again. When the embodiments of the present application are implemented, reference can be made to the above various embodiments, which have corresponding technical effects.

[0083] It can be understood that the embodiments described herein can be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing units can be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSP Devices), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), general purpose processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.

[0084] For software implementation, the techniques described herein can be implemented with a processing unit that executes software routines or functions to perform the techniques described herein. The software code can be stored in a memory and executed by a processor. The memory can be implemented within the processor or external to the processor.

[0085] Those of ordinary skill in the art can understand that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solutions. Those of ordinary skill in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0086] Those of ordinary skill in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0087] In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method can be implemented by other ways. For example, the apparatus embodiments described above are only schematic, and the division of the modules is only a logical function division, and there can be another division in actual implementation, for example, a plurality of modules or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the shown or discussed units can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0088] The units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, i.e. may be located in one place, or may also be distributed on multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme. In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present alone, or two or more units can be integrated in one unit.

[0089] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the embodiments of the present application can be embodied in the form of software products in essence or the parts of the technical solutions that make contributions to the prior art, and the computer software products are stored in a storage medium, including a plurality of instructions for causing an electronic device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a ROM, a RAM, a magnetic disk or an optical disk, and various storage medium that can store program codes.

[0090] It should be noted that, in this paper, relationship terms such as first, second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the term includes, includes or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the sentence "including a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0091] The above is only a specific embodiment of the present application, which enables those skilled in the art to understand or implement the present application. Various modifications of these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A method of digital imaging based on ray filtration, characterized in that, The method comprises the following steps: Based on the X-ray images of aluminum sheets with different thicknesses, X-ray spectrum fitting is performed to obtain an X-ray spectrum, and a hardening correction parameter of X-ray passing through a scanned object is obtained according to the X-ray spectrum; Based on the attenuation value of the X-ray scan image, the first equivalent water thickness of the aluminum sheet is calculated in combination with the hardening correction parameter, and a mapping relationship between the equivalent water thickness and the aluminum sheet thickness is established according to the first equivalent water thickness; Based on the business scan image, the human body region image information is extracted, and the second equivalent water thickness of the human body region image is obtained in combination with the hardening correction parameter; Based on the mapping relationship between the equivalent water thickness and the aluminum sheet thickness, the target aluminum thickness of the additional filtering is determined according to the second equivalent water thickness, and the equivalent water thickness of the human body is compensated during scanning according to the target aluminum thickness.

2. The method of claim 1, wherein, The method comprises the following steps: Based on the X-ray images of aluminum sheets with different thicknesses, X-ray spectrum fitting is performed to obtain an X-ray spectrum, and a hardening correction parameter of X-ray passing through a scanned object is obtained according to the X-ray spectrum; Based on the X-ray imaging device, the aluminum sheets with different thicknesses are sequentially imaged to obtain an X-ray image sequence containing aluminum sheet attenuation information; The average gray value of the X-ray image sequence is obtained to establish a linear relationship between image gray value and transmission intensity, and a transmission intensity model is constructed based on energy integration according to the linear relationship; The X-ray spectrum is calculated by taking the minimum error sum of squares of the calculated value of the transmission intensity model and the actual transmission intensity as the objective function; 3. The method of claim 1, wherein, Based on the X-ray spectrum, the attenuation process of X-ray passing through the substance is simulated and calculated by the transmission intensity model to obtain the hardening correction parameter for attenuation compensation of the X-ray hardening effect. The method comprises the following steps: The air scan image and the human body scan image under X-ray are obtained, and the air scan image and the human body scan image are corrected by using the detector respectively; The ratio of the corrected air scan image and the human body scan image is calculated to obtain the first attenuation value of the scan image; The first attenuation value is preprocessed to obtain the linearized second attenuation value; 4. The method of claim 1, wherein, The first equivalent water thickness of the aluminum sheet is calculated by a correction function according to the second attenuation value and the hardening correction parameter. The method comprises the following steps: Based on the first equivalent water thickness, a polynomial high-order fitting model is used to fit the corresponding relationship curve between the equivalent water thickness and the aluminum sheet thickness; 5. The method of claim 3, wherein the method is a method of ray-filtered digital imaging, further comprising: According to the fitting result, a relationship function is constructed to represent the mapping relationship between the aluminum sheet thickness and the equivalent water thickness. The method comprises the following steps: Based on the image segmentation algorithm, the human body region of the business scan image under X-ray is identified, and the target region pixels are extracted; Based on the target region pixels, the target attenuation value of the business scan image is obtained; Based on the target attenuation value of the service scan image and the hardening correction parameter, an equivalent water thickness of each pixel in the human region image is calculated by the correction function; Based on the pixel statistical features of the human region image, the corresponding equivalent water thickness is counted to obtain the overall equivalent water thickness of the human region image, which is taken as the second equivalent water thickness.

6. The method of claim 5, wherein, The target attenuation value of the service scan image based on the target region pixel includes: The third attenuation value of the service scan image is obtained based on the ratio of the target region pixel to the air scan image under X-rays; The target attenuation value of the service scan image after linearization is obtained by data preprocessing of the third attenuation value.

7. The method of claim 1, wherein, The target aluminum thickness of additional filtering is determined according to the second equivalent water thickness based on the mapping relationship between the equivalent water thickness and the aluminum sheet thickness, and the equivalent water thickness of the human body is compensated during scanning according to the target aluminum thickness, including: The target equivalent water thickness of the human region is determined based on the X-ray target imaging requirement, and the equivalent water thickness compensation amount is obtained according to the difference between the second equivalent water thickness and the target equivalent water thickness; The target aluminum thickness is obtained by calculating the relationship function according to the equivalent water thickness compensation amount based on the mapping relationship between the equivalent water thickness and the aluminum sheet thickness; The equivalent water thickness of the human body is compensated during scanning according to the target aluminum thickness.

8. A digital imaging system based on ray filtration, characterized in that, The system includes: An X-ray spectrum module is configured to perform X-ray spectrum fitting based on X-ray images of aluminum sheets with different thicknesses, obtain an X-ray spectrum, and obtain a hardening correction parameter of X-rays passing through a scanning object according to the X-ray spectrum; An aluminum thickness mapping module is configured to calculate a first equivalent water thickness of an aluminum sheet based on the attenuation value of a scan image under X-rays and in combination with the hardening correction parameter, and establish a mapping relationship between the equivalent water thickness and the aluminum sheet thickness according to the first equivalent water thickness; A human image analysis module is configured to extract human region image information based on a service scan image, and obtain a second equivalent water thickness of the human region image in combination with the hardening correction parameter; An image gray compensation module is configured to determine a target aluminum thickness of additional filtering in an X-ray scanning device according to the second equivalent water thickness based on the mapping relationship between the equivalent water thickness and the aluminum sheet thickness, and compensate the equivalent water thickness of the human body during scanning according to the target aluminum thickness.

9. A digital radiography apparatus comprising: An X-ray scanning device, a filtering aluminum sheet, a detector, and a main control module, the X-ray scanning device emits X-rays and scans the human body through the filtering aluminum sheet, the detector images based on X-rays and transmits imaging data to the main control module, when the digital radiography equipment is running, the main control module executes machine readable instructions to realize the steps of the digital imaging method based on ray filtering in any one of claims 1 to 7.

10. A computer medium having non-transitory program code executable by a processor, the program code comprising instructions for: The computer readable storage medium stores a computer program, and the computer program is executed by the main control module to perform the steps of the digital imaging method based on ray filtering in any one of claims 1 to 7.

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