A dynamic correction method for vehicle security inspection radiation images

Abstract

The present invention belongs to the technical field of vehicle security inspection, and specifically relates to a method for dynamic correction of vehicle security inspection radiation images. An unloaded reference image is collected, including a radiographic image of a stationary vehicle-free gantry, a background noise correction image, and a moving unloaded radiographic image; the row mean and overall mean of the radiographic image of the stationary vehicle-free gantry along the width direction, and the row mean and overall mean of the background noise correction image along the width direction are calculated; and the detector correction coefficient is calculated based on the row mean and overall mean of the radiographic image of the stationary vehicle-free gantry along the width direction, and the row mean and overall mean of the background noise correction image along the width direction; based on the moving unloaded radiographic image and the detector correction coefficient, a motion correction coefficient is calculated to correct the vehicle security inspection radiation image. The dynamic correction method can effectively eliminate the problem of light and dark vertical stripes in the radiation image caused by the asynchronous movement of the two sides of the gantry.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle security inspection, and in particular relates to a method for dynamic correction of radiation images of vehicle security inspection. Background Art

[0002] In the field of vehicle security inspection, non-contact inspection technology is widely used due to its high efficiency and non-destructive nature. For vehicles requiring security inspection, a fixed security inspection channel structure is typically used. A gantry for security inspection equipment spans both sides of the track. One side of the gantry is equipped with imaging equipment, such as an X-ray imager or gamma ray imager, and the other side is equipped with a radiation source, such as an X-ray generator or gamma ray source. The imaging equipment and radiation source are driven by two independent motors, traveling synchronously along the track to achieve panoramic scanning and imaging of the inspected vehicle.

[0003] However, in practice, due to differences in mechanical structure, motor performance, transmission system, and environmental factors, achieving complete synchronization between the two devices is difficult. This asynchronous movement can cause a misalignment in the relative position of the imaging device and the radiation source, resulting in alternating vertical streaks of light and dark in the radiation image. These artifacts not only reduce the visual quality of the image but can also obscure or distort the true characteristics of the inspected goods, affecting security personnel's interpretation of the image and the accuracy of anomaly detection.

[0004] Therefore, a new technical solution is needed to effectively eliminate vertical streak artifacts in radiation images and improve image quality and security inspection accuracy. Summary of the Invention

[0005] In order to overcome the problems in the prior art, the present invention proposes a method for dynamic correction of vehicle security inspection radiation images.

[0006] The technical solution of the present invention to solve the above technical problems is as follows:

[0007] A method for dynamic correction of vehicle security inspection radiation images, comprising the following steps:

[0008] Collect unloaded reference images, including stationary vehicle-free gantry radiographic images, background noise correction images, and moving unloaded radiographic images;

[0009] Calculate the row mean and overall mean of the radiographic image of the stationary vehicle-free gantry along the width direction, and the row mean and overall mean of the background noise corrected image along the width direction; and calculate the detector correction coefficient based on the row mean and overall mean of the radiographic image of the stationary vehicle-free gantry along the width direction, and the row mean and overall mean of the background noise corrected image along the width direction;

[0010] Based on the motion unloaded radiation image and the detector correction coefficient, the motion correction coefficient is calculated to correct the vehicle security inspection radiation image.

[0011] Furthermore, the width direction refers to the transverse path of the ray from the source to the detector, that is, the transverse dimension of the image.

[0012] Furthermore, the row mean and overall mean of the radiographic image of the stationary vehicle-free gantry along the width direction are calculated, including:

[0013] If the ray image of a stationary vehicle-free gantry is a two-dimensional matrix , where x represents the width direction and y represents the length direction; Indicates the width of the image, and H indicates the height of the image;

[0014] For each row, calculate the average of all pixel values ​​in each row :

[0015] ;

[0016] In the above formula, represents the mean of the yth row of the radiographic image of a stationary vehicle-free gantry, i.e., the average feature of the yth row in the width direction;

[0017] The mean of each row Form a one-dimensional vector ,Right now:

[0018] ;

[0019] In the above formula, A one-dimensional vector representing the row mean of the radiographic image of a stationary vehicle-free gantry;

[0020] Calculate the overall mean of the radiographic image of a stationary vehicle-free gantry along the width direction:

[0021] ;

[0022] In the above formula, Represents the mean value of all pixel values ​​of the AO image of the vehicle-free gantry.

[0023] Furthermore, the row mean and the overall mean of the background noise correction image along the width direction are calculated, including:

[0024] If the background noise correction image is a two-dimensional matrix , where x represents the width direction and y represents the length direction; Indicates the width of the image, and H indicates the height of the image;

[0025] For each row, calculate the average of all pixel values ​​in each row :

[0026] ;

[0027] In the above formula, represents the mean of the y-th row of the background noise correction image, that is, the average feature of the y-th row in the width direction;

[0028] The mean of each row Form a one-dimensional vector ,Right now:

[0029] ;

[0030] In the above formula, A one-dimensional vector representing the row mean of the noise floor corrected image;

[0031] Calculate the overall mean of the noise floor corrected image along the width direction:

[0032] ;

[0033] In the above formula, Represents the mean value of all pixels in the background noise correction image BO.

[0034] Furthermore, the detector correction coefficient is calculated based on the row mean and overall mean of the stationary vehicle-free gantry radiographic image along the width direction and the row mean and overall mean of the background noise correction image along the width direction, including:

[0035] ;

[0036] In the above formula, Indicates the detector correction factor; A one-dimensional vector representing the row mean of the radiographic image of a stationary vehicle-free gantry; Represents the mean value of all pixel values ​​in the ray image of the vehicle-free gantry; A one-dimensional vector representing the row mean of the noise floor corrected image; Represents the mean value of all pixels in the background noise correction image.

[0037] Furthermore, based on the motion unloaded radiographic image and the detector correction coefficient, a motion correction coefficient is calculated to correct the vehicle security inspection radiation image, including:

[0038] Convert the moving empty-load ray image into a two-dimensional array of moving empty-load ray images;

[0039] Based on the two-dimensional array of the moving empty-load radiographic image and the row mean of the background noise correction image, the net signal quantity of all pixels in the moving empty-load radiographic image is obtained;

[0040] Based on the detector correction coefficient, the net signal amount of all pixels of the moving no-load radiographic image is corrected to obtain the corrected net signal amount of all pixels of the moving no-load radiographic image;

[0041] Calculate the overall mean of the net signal of all pixels in the corrected motion-free radiographic image;

[0042] The motion correction coefficient is calculated based on the net signal amount of all pixels of the corrected motion idle radiographic image and the overall mean value of the net signal amount of all pixels of the corrected motion idle radiographic image.

[0043] Furthermore, the moving idler radiographic image includes a moving idler radiographic image in a forward direction and a moving idler radiographic image in a backward direction.

[0044] Further, based on the moving empty-load radiation image and the detector correction coefficient, a motion correction coefficient is calculated to correct the vehicle security inspection radiation image, including calculating the forward direction motion correction coefficient based on the moving empty-load radiation image in the forward direction and the detector correction coefficient to correct the forward direction vehicle security inspection radiation image;

[0045] The forward motion correction coefficient is:

[0046] ;

[0047] Right now: ;

[0048] In the above formula, Indicates the forward motion correction coefficient; Indicates the detector correction factor; A one-dimensional vector representing the row mean of the noise floor corrected image; A two-dimensional array of unloaded ray images representing the forward direction; It represents the overall mean of the net signal of all pixels in the forward motion free-wheeling radiographic image after correction; It represents the net signal of all pixels in the unloaded radiographic image after correction for forward motion.

[0049] Furthermore, based on the moving idle radiation image and the detector correction coefficient, a motion correction coefficient is calculated to correct the vehicle security inspection radiation image, including calculating a backward direction motion correction coefficient based on the backward direction moving idle radiation image and the detector correction coefficient to correct the vehicle security inspection radiation image in the reverse direction;

[0050] The backward motion correction coefficient is:

[0051] ;

[0052] Right now: ;

[0053] In the above formula, Represents the backward direction motion correction coefficient; Indicates the detector correction factor; A one-dimensional vector representing the row mean of the noise floor corrected image; A two-dimensional array representing an unloaded ray image moving in the backward direction; It represents the overall mean of the net signal of all pixels in the backward motion free-wheeling radiographic image after correction; It represents the net signal of all pixels in the unloaded radiographic image after correction for backward motion.

[0054] Compared with the prior art, the present invention has the following technical effects:

[0055] Dynamic correction effectively eliminates vertical streaks in radiometric images caused by the asynchronous movement of the two sides of the gantry. The corrected image achieves a more uniform grayscale distribution across its width, sharper details, and significantly improved overall image quality. This not only helps security personnel more accurately identify prohibited or dangerous items, but also reduces false positives and missed detections caused by poor image quality, improving the accuracy and reliability of security checks. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0057] Figure 1 It is a schematic diagram of the process of the present invention;

[0058] Figure 2 This is the vehicle security inspection radiation image before correction;

[0059] Figure 3 This is the corrected vehicle security inspection radiation image;

[0060] Figure 4 This is the radiographic image of a stationary vehicle-free gantry;

[0061] Figure 5 For the forward direction motion unloaded radiographic image;

[0062] Figure 6 It is an unloaded radiographic image moving in the backward direction. DETAILED DESCRIPTION

[0063] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose of the invention, the following, in conjunction with the accompanying drawings and preferred embodiments, describes in detail the specific implementation methods, structures, features, and effects of the technical solutions proposed by the present invention. Specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0064] In one embodiment of the present invention, referring to Figures 1-6 , provides a vehicle security inspection radiation image dynamic correction method, comprising the following steps:

[0065] Step 100: Acquire an unloaded reference image, including a stationary vehicle-free gantry radiographic image, a background noise correction image, and a moving unloaded radiographic image;

[0066] Step 200: Calculate the mean and overall mean of the radiographic image of the stationary vehicle-free gantry along the width direction, and the mean and overall mean of the background noise corrected image along the width direction; and calculate the detector calibration coefficient based on the mean and overall mean of the radiographic image of the stationary vehicle-free gantry along the width direction, and the row mean and overall mean of the background noise corrected image along the width direction;

[0067] Step 300: Calculate a motion correction coefficient based on the motion idle radiographic image and the detector correction coefficient, and correct the vehicle security inspection radiation image.

[0068] The following is a detailed explanation of each of the above steps:

[0069] Step 100: Collecting an empty reference image, including a stationary vehicle-free gantry radiographic image, a background noise correction image, and a moving empty radiographic image. The moving empty radiographic image includes a moving empty radiographic image in the forward direction and a moving empty radiographic image in the backward direction.

[0070] Reference Figure 4-Figure 6 , collect the radiographic image of the stationary vehicle-free gantry. At this time, the gantry is stationary and no vehicle passes through. This image is recorded as AO;

[0071] Acquire a background noise correction image, that is, a noise image generated only by the imaging device itself after the radiation signal is turned off, which is used for subsequent correction of detector noise. This image is recorded as BO;

[0072] Collect the unloaded radiographic image when the gantry moves in the forward direction. At this time, the unloaded radiographic image when the gantry moves along the track in the 'forward direction', with no vehicle passing, is named AF.

[0073] Collect an unloaded radiographic image of the gantry moving in the backward direction. At this time, collect an unloaded radiographic image of the gantry moving in the backward direction. There is also no vehicle passing through. It is named AB.

[0074] Step 200: Calculate the mean and overall mean of the radiographic image of the stationary vehicle-free gantry along the width direction, and the mean and overall mean of the background noise correction image along the width direction; and calculate the detector correction coefficient based on the mean and overall mean of the radiographic image of the stationary vehicle-free gantry along the width direction, and the mean and overall mean of the background noise correction image along the width direction.

[0075] As an example, this step 200 may include the following sub-steps:

[0076] Step 210: Based on the radiographic image of the stationary vehicle-free gantry, calculate the mean and the overall mean along the width direction.

[0077] In a stationary, vehicle-free gantry radiographic image, the width direction refers to the lateral span from the X-ray source to the detector, corresponding to the horizontal dimension of the image. Specifically, the X-ray source, located on one side of the gantry, emits X-rays, while the detector, located on the other side, receives X-rays that have passed through the object. The width direction refers to the lateral path of the rays from the source to the detector, i.e., the horizontal dimension of the image.

[0078] Assume the image is a two-dimensional matrix , where x represents the width direction (horizontal) and y represents the length direction (vertical); represents the width of the image (the number of horizontal pixels), and H represents the height of the image (the number of vertical pixels).

[0079] For each row, calculate the average of all pixel values ​​in that row :

[0080] ;

[0081] In the above formula, It represents the mean of the yth row of the radiographic image of the stationary vehicle-free gantry, that is, the average feature of the row in the width direction.

[0082] The mean of each row Form a one-dimensional vector ,Right now:

[0083] ;

[0084] In the above formula, A one-dimensional vector representing the row mean of the radiographic image of the stationary vehicle-free gantry.

[0085] Calculate the overall mean of the AO image of the stationary vehicle-free gantry along the width direction. The overall mean refers to the average of all pixel values ​​of the AO image of the stationary vehicle-free gantry to obtain a scalar value:

[0086] ;

[0087] In the above formula, Represents the mean value of all pixel values ​​of the AO image of the vehicle-free gantry.

[0088] Step 220: Based on the background noise correction image, calculate its row mean and overall mean along the width direction.

[0089] Assume the image is a two-dimensional matrix , where x represents the width direction (horizontal) and y represents the length direction (vertical); represents the width of the image (the number of horizontal pixels), and H represents the height of the image (the number of vertical pixels).

[0090] For each row, calculate the average of all pixel values ​​in that row :

[0091] ;

[0092] In the above formula, It represents the mean of the y-th row of the background noise correction image, that is, the average feature of the row in the width direction.

[0093] The mean of each row Form a one-dimensional vector ,Right now:

[0094] ;

[0095] In the above formula, A one-dimensional vector representing the row means of the noise floor corrected image.

[0096] Calculate the overall mean of the noise floor correction image along the width direction. The overall mean refers to the average of all pixel values ​​of the noise floor correction image to obtain a scalar value:

[0097] ;

[0098] In the above formula, Represents the mean value of all pixels in the background noise correction image BO.

[0099] Step 230: Based on the row mean and overall mean of the stationary vehicle-free gantry radiographic image AO along the width direction, and in combination with the row mean and overall mean of the background noise correction image BO along the width direction, calculate the imaging system detector correction coefficient:

[0100] ;

[0101] In the above formula, Indicates the detector correction factor.

[0102] Step 300: Calculate a motion correction coefficient based on the motion idle radiographic image and the detector correction coefficient, and correct the vehicle security inspection radiation image.

[0103] The moving unloaded ray image is converted into a two-dimensional array of the moving unloaded ray image; based on the row mean of the two-dimensional array of the moving unloaded ray image and the background noise correction image, the net signal quantity of all pixels of the moving unloaded ray image is obtained; based on the detector correction coefficient, the net signal quantity of all pixels of the moving unloaded ray image is corrected to obtain the corrected net signal quantity of all pixels of the moving unloaded ray image; the overall mean value of the net signal quantity of all pixels of the corrected moving unloaded ray image is calculated; based on the net signal quantity of all pixels of the corrected moving unloaded ray image and the overall mean value of the net signal quantity of all pixels of the corrected moving unloaded ray image, the motion correction coefficient is calculated.

[0104] The moving idle radiation image includes a forward moving idle radiation image and a backward moving idle radiation image. For the forward moving idle radiation image, a forward motion correction coefficient is calculated based on the forward moving idle radiation image and the detector correction coefficient, and correction is performed on the forward vehicle security inspection radiation image, which may include the following sub-steps:

[0105] Step 3101: Convert the forward direction motion empty-load radiographic image AF into a two-dimensional array of forward direction motion empty-load radiographic images .

[0106] Step 3102: Based on the two-dimensional array of the forward-moving unloaded ray image and the row mean of the background noise correction image, the net signal amount of all pixels in the forward-moving unloaded ray image is obtained:

[0107] ;

[0108] In the above formula, It represents the net signal of all pixels in the forward moving empty radiographic image AF.

[0109] Step 3103: Based on the detector correction coefficient, the net signal amount of all pixels of the forward-moving unloaded ray image is corrected to obtain the corrected net signal amount of all pixels of the forward-moving unloaded ray image.

[0110] Perform imaging system correction on all pixels of the forward moving unloaded radiographic image AF, and the corrected values ​​are:

[0111] ;

[0112] In the above formula, It represents the net signal of all pixels in the unloaded radiographic image after correction for forward motion.

[0113] Step 3104: Calculate the overall mean of the net signal of all pixels in the corrected forward direction motion idle ray image .

[0114] Step 3105: Calculate the forward motion correction coefficient based on the net signal of all pixels in the corrected forward motion unloaded ray image and the overall mean of the net signal of all pixels in the corrected forward motion unloaded ray image. :

[0115] ;

[0116] Right now: ;

[0117] Step 3106: Based on the forward direction motion correction coefficient, the forward direction vehicle security inspection radiation image is corrected.

[0118] Radiation image of vehicle security inspection in the forward direction I , vehicle security inspection radiation image in the forward direction after dynamic correction:

[0119] ;

[0120] In the above formula, It represents the corrected vehicle security inspection radiation image in the forward direction.

[0121] For the backward motion idle radiographic image, based on the backward motion idle radiographic image and the detector correction coefficient, the forward motion correction coefficient is calculated to correct the forward motion vehicle security inspection radiation image, which may include the following sub-steps:

[0122] Step 3201: Convert the backward direction motion idler ray image AB into a two-dimensional array of backward direction motion idler ray images.

[0123] Step 3202: Based on the two-dimensional array of the backward-moving idler ray image and the row mean of the background noise correction image, the row mean of the two-dimensional array of the backward-moving idler ray image and the background noise correction image are subtracted column by column along the column direction to obtain the net signal amount of all pixels in the backward-moving idler ray image:

[0124] ;

[0125] In the above formula, It represents the net signal of all pixels in the unloaded X-ray image AB moving in the backward direction.

[0126] Step 3203: Based on the detector correction coefficient, the net signal amount of all pixels of the backward direction moving unloaded ray image is corrected to obtain the corrected net signal amount of all pixels of the backward direction moving unloaded ray image.

[0127] Perform imaging system correction on all pixels of the backward motion unloaded radiographic image AB. The corrected values ​​are :

[0128] ;

[0129] Step 3204: Calculate the overall mean of the net signal quantities of all pixels in the corrected backward motion idle ray image.

[0130] Step 3205: Based on the net signal amounts of all pixels in the corrected backward direction motion idle ray image and the overall mean value of the net signal amounts of all pixels in the corrected backward direction motion idle ray image, a backward direction motion correction coefficient is calculated:

[0131] ;

[0132] Right now: ;

[0133] Step 3206: Based on the forward direction motion correction coefficient, the forward direction vehicle security inspection radiation image is corrected.

[0134] Radiation image of vehicle security inspection in the forward direction , the image after dynamic correction :

[0135] .

[0136] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A method for dynamic correction of vehicle security inspection radiation images, characterized in that: The following steps are involved: Collect unloaded reference images, including stationary vehicle-free gantry radiographic images, background noise correction images, and moving unloaded radiographic images; Calculate the row mean and overall mean of the radiographic image of the stationary vehicle-free gantry along the width direction, and the row mean and overall mean of the background noise corrected image along the width direction; and calculate the detector correction coefficient based on the row mean and overall mean of the radiographic image of the stationary vehicle-free gantry along the width direction, and the row mean and overall mean of the background noise corrected image along the width direction, including: ； In the above formula, Indicates the detector correction factor; A one-dimensional vector representing the row mean of the radiographic image of a stationary vehicle-free gantry; Represents the mean value of all pixel values ​​in the ray image of the vehicle-free gantry; A one-dimensional vector representing the row mean of the noise floor corrected image; Represents the mean value of all pixel values ​​in the background noise correction image; Based on the motion unloaded radiographic image and the detector correction coefficient, the motion correction coefficient is calculated to correct the vehicle security inspection radiation image, including: Convert the moving empty-load ray image into a two-dimensional array of moving empty-load ray images; Based on the two-dimensional array of the moving empty-load radiographic image and the row mean of the background noise correction image, the net signal quantity of all pixels in the moving empty-load radiographic image is obtained; Based on the detector correction coefficient, the net signal amount of all pixels of the moving no-load radiographic image is corrected to obtain the corrected net signal amount of all pixels of the moving no-load radiographic image; Calculate the overall mean of the net signal of all pixels in the corrected motion-free radiographic image; The motion correction coefficient is calculated based on the net signal amount of all pixels of the corrected motion idle radiographic image and the overall mean value of the net signal amount of all pixels of the corrected motion idle radiographic image.

2. The method for dynamic correction of vehicle security inspection radiation images according to claim 1, characterized in that: The width direction refers to the transverse path of the ray from the source to the detector, that is, the transverse dimension of the image.

3. The method for dynamic correction of vehicle security inspection radiation images according to claim 1, characterized in that: Calculate the row mean and overall mean of the radiographic image of a stationary vehicle-free gantry along the width direction, including: If the ray image of a stationary vehicle-free gantry is a two-dimensional matrix , where x represents the width direction and y represents the length direction; Indicates the width of the image, and H indicates the height of the image; For each row, calculate the average of all pixel values ​​in each row : ； In the above formula, represents the mean of the yth row of the radiographic image of a stationary vehicle-free gantry, i.e., the average feature of the yth row in the width direction; The mean of each row Form a one-dimensional vector ,Right now: ； In the above formula, A one-dimensional vector representing the row mean of the radiographic image of a stationary vehicle-free gantry; Calculate the overall mean of the radiographic image of a stationary vehicle-free gantry along the width direction: ； In the above formula, Represents the mean value of all pixel values ​​of the AO image of the vehicle-free gantry.

4. The method for dynamic correction of vehicle security inspection radiation images according to claim 1, characterized in that: Calculate the row mean and overall mean of the noise floor corrected image along the width direction, including: If the background noise correction image is a two-dimensional matrix , where x represents the width direction and y represents the length direction; Indicates the width of the image, and H indicates the height of the image; For each row, calculate the average of all pixel values ​​in each row : ； In the above formula, represents the mean of the y-th row of the background noise correction image, that is, the average feature of the y-th row in the width direction; The mean of each row Form a one-dimensional vector ,Right now: ； In the above formula, A one-dimensional vector representing the row mean of the noise floor corrected image; Calculate the overall mean of the noise floor corrected image along the width direction: ； In the above formula, Represents the mean value of all pixels in the background noise correction image BO.

5. The method for dynamic correction of vehicle security inspection radiation images according to claim 1, characterized in that: The moving idle ray images include a forward direction moving idle ray image and a backward direction moving idle ray image.

6. The method for dynamic correction of vehicle security inspection radiation images according to claim 5, characterized in that: Based on the moving empty-load radiation image and the detector correction coefficient, a motion correction coefficient is calculated to correct the vehicle security inspection radiation image, including calculating the forward direction motion correction coefficient based on the moving empty-load radiation image in the forward direction and the detector correction coefficient to correct the vehicle security inspection radiation image in the forward direction; The forward motion correction coefficient is: ； Right now: ; In the above formula, Indicates the forward motion correction coefficient; Indicates the detector correction factor; A one-dimensional vector representing the row mean of the noise floor corrected image; A two-dimensional array of unloaded ray images representing the forward direction; It represents the overall mean of the net signal of all pixels in the forward motion free-wheeling radiographic image after correction; It represents the net signal of all pixels in the unloaded radiographic image after correction for forward motion.

7. The method for dynamic correction of vehicle security inspection radiation images according to claim 5, characterized in that: Based on the moving empty-load radiation image and the detector correction coefficient, a motion correction coefficient is calculated to correct the vehicle security inspection radiation image, including based on the moving empty-load radiation image in the backward direction and the detector correction coefficient, a backward direction motion correction coefficient is calculated to correct the vehicle security inspection radiation image in the reverse direction; The backward motion correction coefficient is: ； Right now: ; In the above formula, Represents the motion correction coefficient in the backward direction; Indicates the detector correction factor; A one-dimensional vector representing the row mean of the noise floor corrected image; A two-dimensional array representing an unloaded ray image moving in the backward direction; It represents the overall mean of the net signal of all pixels in the backward motion free-wheeling radiographic image after correction; It represents the net signal of all pixels in the unloaded radiographic image after correction for backward motion.

Images