CN105759318B - Safety detection device and detection method thereof - Google Patents

Abstract

The invention relates to a safety detection device and a detection method thereof. The safety detection device includes a CT detection device and a multi-view detection device. The CT detection device and the multi-view detection device share a detection channel; and a transmission device is also included. Pass through the detection channel of the CT detection device and the detection channel of the multi-view detection device. The safety detection method includes the detection object passing through the CT detection device and the multi-view detection device, or the detected object passing through the multi-view detection device and the CT detection device. The superior effect of the invention is that: the multi-view detection device is used in combination with the CT detection device, and the CT detection device is used to obtain the three-dimensional tomographic structure information of the detected object, thereby improving the detection accuracy of the detected object; at the same time, the multi-view detection device is used to compensate for The shortcomings of the CT detection device for the detection of atomic numbers in the environment of high-density metal objects are reduced, and the accuracy of the entire detection device is improved while reducing the equipment cost.

Description

A safety detection device and detection method thereof

technical field

The invention relates to the technical field of safety detection, in particular to a safety detection device and a detection method thereof.

Background technique

For the detection of explosives, the technical means commonly used in the world at this stage are roughly divided into X-ray detection technology, neutron detection technology, electromagnetic detection technology, and vapor trace detection technology. X-ray technology is currently the most widely used due to its own unique advantages. Security Check Technology. X-ray security inspection technology mainly includes single-energy fluoroscopy technology, dual-energy fluoroscopy technology, multi-view technology, backscatter technology, single-energy spectral CT technology, dual-energy CT technology, etc. The single-energy fluoroscopy technology is the earliest X-ray security inspection technology used. It can only obtain the shape information of the objects in the package, but cannot obtain the material information. use. Dual-energy fluoroscopy technology is currently the most widely used technology in X-ray fluoroscopy security inspection technology on the market. It obtains the high and low energy projections of objects without object occlusion by means of material peeling, and then determines the atomic number information of materials. Although dual-energy fluoroscopic imaging technology can approximately determine the effective atomic number of a substance, it cannot obtain the density information of the object. The multi-view technology makes up for this shortcoming to a certain extent. This technology can obtain approximate dangerous goods through multi-view projection CT reconstruction. Thickness information, based on the thickness information and the projection value, it is possible to approximately determine the density of the material. The detection error of this technique is relatively large because it is difficult to accurately reconstruct the cross-section of the object from projections from a small number of viewing angles. Backscattering technology is mostly used to detect dangerous goods on the surface of packages due to its sensitivity to low atomic number and high density substances. X-ray computed tomography (CT, Computed Tomography) technology, as an important non-contact internal vision detection method, plays an increasingly important role in the fields of medical diagnosis, non-destructive testing, and safety inspection. Especially in the field of security inspection, CT-type equipment is currently the only EDS (Explosive Detection System)-type security inspection equipment certified by the Transportation Security Administration (TSA), which shows the status of X-ray CT technology in the field of security inspection technology. Usually X-ray CT technology can be divided into single-energy spectrum CT technology and multi-energy spectrum CT technology. Single-energy spectrum CT technology can obtain information on the attenuation coefficient of substances (equivalent to density by conversion). This technology is simply copied from medical CT technology. However, only density information can be obtained, so it still has certain limitations. The X-ray dual-energy CT technology in the multi-energy spectral CT technology has the highest detection accuracy in the X-ray security inspection technology because it can obtain the atomic number and density information of the substance at the same time, so it has been obtained more and more in the security inspection. Applications. However, in terms of equipment cost, the cost of single-energy spectral CT is significantly lower than that of multi-energy spectral CT. In addition, even for multi-energy spectral CT, such as the most commonly used dual-energy CT, if there are high-density metal objects in the detected baggage, the analytical accuracy of its atomic number will be significantly reduced.

The Chinese patent with publication number CN101470082A discloses an article detection device and a detection method. The device includes an X-ray system and a CT system, and comprehensively utilizes the information collected by the X-ray system and the CT system to identify dangerous goods. Increase the data information used for judgment to improve the accuracy of judgment. The device only utilizes an X-ray system with a single viewing angle, and has a simple structure and low precision.

The international patent publication No. EP2676128A2 discloses a multi-scanner system and method. The system includes a CT device and a multi-energy scanner. During detection, the object first passes through the CT device, and the tomographic information of the CT and subsequent multi-energy scanners are used. The information obtained by the scanner can be combined to identify dangerous goods. The device is not a combined detection mode of CT and multi-view equipment.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies in the prior art, and to provide a high-precision safety detection device and a detection method thereof.

The present invention is achieved through the following technical solutions:

A safety detection device, comprising a CT detection device and a multi-view detection device arranged on one side of the CT detection device, the CT detection device and the multi-view detection device share a detection channel;

The CT detection device is connected to the first control and data processing computer; the multi-view detection device is provided with a multi-view detector and a ray source module, and the multi-view detector is connected to the second control and data processing computer; the The first control and data processing computer and the second control and data processing computer are all connected to the integrated data processing computer;

The safety detection device further includes a transmission device, and the transmission device passes through the detection channel of the CT detection device and the detection channel of the multi-view detection device.

In the technical solution, preferably, the CT detection device includes a CT ray source module, a CT gantry, and a CT detector, and the CT ray source module and the CT detector are both arranged on the CT gantry.

In the technical solution, preferably, the CT detection device adopts one of a single-energy spectrum CT detection device and a multi-energy spectrum CT detection device.

In the technical solution, preferably, the diameter of the channel of the CT detection device is 80cm-120cm.

In the technical solution, preferably, the CT detector adopts one of a single-layer detector, a double-layer detector, and a photon counting detector.

In the technical solution, preferably, the number of viewing angles of the multi-viewing angle detection device is 2-4.

The technical solution is preferably that the multi-view detector adopts one of a single-layer detector, a double-sandwich detector, and a photon counting detector.

The present invention provides a safety detection method, comprising at least the following steps:

a: Place the detected object on the running transmission setup, the detected object passes through the CT detection device, and the first control and data processing computer obtains the three-dimensional tomographic structure information, density information and atomic number information of the detected object , obtain the region of interest of the detected object according to the density information and atomic number information;

b: The detected object passes through the multi-view detection device, and the second control and data processing computer obtains perspective image information of the detected object from multiple perspectives; Effective atomic number information; or correct atomic number information by atomic number correction method to obtain effective atomic number information;

c: The comprehensive data processing computer obtains the density information and effective atomic number information of the detected object, and determines whether to give alarm information by searching the database.

The present invention also provides a safety detection method, comprising at least the following steps:

a: The detected object is placed on the running transmission setting, the detected object passes through the multi-view detection device, and the second control and data processing computer obtains the perspective image information and atomic number information of the detected object from multiple perspectives, Obtain the region of interest of the detected object according to the perspective image information and atomic number information of the detected object from multiple viewing angles;

b: The detected object passes through the CT detection device, and the first control and data processing computer obtains the three-dimensional tomographic structure information, density information and atomic number information of the detected object; ordinal information, obtain the effective atomic number information of the region of interest; or correct the atomic number information by the atomic number correction method to obtain the effective atomic number information;

c: The comprehensive data processing computer obtains the density information and effective atomic number information of the detected object, and determines whether to give alarm information by searching the database.

The technical solution is preferably that the CT detection device adopts a single-energy spectrum CT detection device, and the atomic number information is corrected by an atomic number correction method, including the following steps:

1) Obtaining a region of interest according to the three-dimensional tomographic structure information of the detected object, and analyzing the degree of overlapping of objects in each projected viewing angle of the region of interest along the ray-casting direction, to obtain a parameter of the degree of object overlapping under each viewing angle;

2) When the multi-view detection device obtains 2-4 perspective projection views, select the object overlap degree parameter to calculate the effective atomic number;

The CT detection device adopts a multi-energy spectrum CT detection device, and the atomic number information is corrected by an atomic number correction method, including the following steps:

1) Obtain a region of interest according to the three-dimensional tomographic structure information of the detected object, and analyze the overlapping degree of the region of interest and the metal object in each projection view of the region of interest along the ray projection direction, and obtain the overlapping degree parameter of the metal object in each view;

2) When the multi-angle detection device obtains 2-4 perspective projection angles, select the parameter of the overlapping degree of metal objects to calculate the effective atomic number.

The technical solution is preferably that the method for calculating the object overlap degree parameter includes: normalizing the projected grayscale curve, taking it as a probability density function of position information, and calculating the mean square error under the probability density function, As the value of the object overlapping degree parameter; the larger the value, the lower the object overlapping degree, and vice versa; Orthographic projection is performed on the viewing angle directions and imaging geometric parameters of multiple viewing angles to obtain the projected grayscale curve of the object after removing the region of interest, and the mean value of the projection data corresponding to the projection position of the region of interest is calculated as the overlap degree parameter. The smaller the mean, the smaller the overlap of objects.

The technical solution is preferably that the method for calculating the overlapping parameters of the metal objects includes: locating the region of interest of the detected object and determining the metal region inside the object by setting a threshold value, and determining the metal region within the region of interest and outside the metal region. The image in the metal area is set to 0, the image in the metal area is set to 1, and then the orthographic projection is performed according to the viewing angle direction of the multi-view angle and the imaging geometric parameters to obtain the projected grayscale curve of the object after removing the area of interest, and calculate the The mean value of the projection data corresponding to the projection position of the region of interest is used as the overlap degree parameter. The smaller the mean, the smaller the overlap of objects.

In the technical solution, preferably, the density of the region of interest is 1.2-1.5 g/cm ³ , and the atomic number is 6-8.

Compared with the prior art, the present invention has the advantages that: the multi-view detection device is used in combination with the CT detection device, and the CT detection device is used to obtain the three-dimensional tomographic structure information of the detected object, thereby improving the detection accuracy of the detected object; At the same time, the multi-view detection device is used to make up for the shortcomings of the CT detection device for the reduction of the atomic number detection accuracy in the environment of high-density metal objects, and the accuracy of the entire detection device is improved while reducing the equipment cost.

Description of drawings

1 is a schematic structural diagram of a first embodiment of the safety detection device according to the present invention;

Fig. 2 is the detection flow chart of the device described in Fig. 1 that first passes through the dual-energy spectrum CT detection device, and then passes through the multi-view detection device;

3 is a schematic structural diagram of a second embodiment of the safety detection device according to the present invention;

Fig. 4 is the detection flow chart of the device described in Fig. 3 that first passes through the multi-view detection device, and then passes through the dual-energy spectrum CT detection device;

Fig. 5 is a flow chart of a safety detection device that first passes through a single-energy spectrum CT detection device, and then passes through a multi-view detection device;

FIG. 6 is a flow chart of the safety detection device using a multi-view detection device first, and then a single-energy spectrum CT detection device;

Fig. 7 is the flow chart of the effective atomic number calculation method when the CT detection device adopts the single-energy spectrum CT detection device;

Fig. 8 is a flow chart of a method for calculating the effective atomic number when the CT detection device adopts a dual-energy spectrum CT detection device and a high-density metal exists in the region of interest;

9 is a schematic flowchart of a method for calculating the degree of object overlap parameter;

FIG. 10 is a schematic flowchart of a second method for calculating the object overlap degree parameter;

FIG. 11 is a schematic flowchart of a method for calculating the overlapping degree parameter of high-density metal objects.

The accompanying drawings are identified as follows:

1-CT ray source module, 2-CT gantry, 3-CT detector, 4-first detector, 5-second detector, 6-second ray source, 7-third detector, 8-th Three ray sources, 9-detected object, 10-first control and data processing computer, 11-first ray source, 12-integrated data processing computer, 13-second control and data processing computer, 14-fourth detector , 15 - the fourth ray source, 16 - the transmission device.

Detailed ways

The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

Example 1

As shown in FIG. 1 , the safety detection device of the present invention includes a CT detection device and a multi-view detection device disposed on one side of the CT detection device. Both the CT detection device and the multi-view detection device share a detection channel. The CT detection device is connected to the first control and data processing computer 10; the multi-view detection device is provided with a multi-view detector and a ray source module, and the multi-view detector is connected to the second control and data processing computer 13; The first control and data processing computer 10 and the second control and data processing computer 13 are all connected to the integrated data processing computer 12 for data exchange. The safety detection device further includes a transmission device 16, and the transmission device 16 passes through the detection channel of the CT detection device and the detection channel of the multi-view detection device. The CT detection device includes a CT ray source module 1, a CT gantry 2, and a CT detector 3. The CT gantry 2 is in the shape of a ring, and the CT ray source module 1 and the CT detector 3 are arranged on the CT gantry. 2 on.

Further, the multi-view detector includes a first detector 4, a second detector 5, a third detector 7, and a fourth detector 14, and the ray source module includes a first ray source 11 and a second ray source 6. The third ray source 8 and the fourth ray source 15 . In the present invention, the first detector 4, the second detector 5, the third detector 7, the fourth detector 14, the first ray source 11, the second ray source 6, the third ray source 8 and the fourth ray source are arranged 15. A safety detection device combined with a CT detection device and a four-view detection device is formed.

The fourth detector 14 and the fourth ray source 15 form a V1 view angle, the third detector 7 and the third ray source 8 form a V2 view angle, and the second detector 5 and the second ray source 6 form V3 viewing angle, the first detector 4 and the first ray source 11 constitute a V4 viewing angle.

When the safety detection device of the present invention is applied, first place the object to be detected 9 on the transmission device 16, start the safety detection device, the transmission device 16 moves to the right at a constant speed, and transports the object to be detected 9 into the detection channel When the detected object 9 reaches the CT detection device, the CT gantry 2 rotates at a constant speed; the detected object 9 triggers the CT ray source module 1, and the CT ray source module 1 sends an X-ray beam to transmit the detected object 9, and the CT The detector 3 receives the corresponding attenuation signal transmitted through the detected object 9; the CT gantry 2 rotates continuously, and the detected object 9 moves synchronously and uniformly with the transmission device 16; at the same time, the CT detector 3 continuously receives different angles The X-ray beam transmits the attenuation signal data of the detected object 9, and transmits the received data to the first control and data processing computer 10, and the first control and data processing computer 10 performs CT reconstruction and data processing.

When the detected object 9 leaves the CT detection device and enters the multi-view detection device, the detected object 9 triggers the first ray source 11 , the second ray source 6 , the third ray source 8 and the fourth ray source 15 in sequence. The source sequentially emits X-ray beams to transmit the detected object 9; the first detector 4, the second detector 5, the third detector 7, and the fourth detector 14 respectively receive the corresponding attenuation transmitted through the detected object 9 signal, and transmit the attenuation signal to the second control and data processing computer 13 to form the corresponding projection image signals of the V4 viewing angle, the V3 viewing angle, the V2 viewing angle, and the V1 viewing angle.

The first control and data processing computer 10 and the second control and data processing computer 13 transmit the received signals to the integrated data processing computer 12 , and through data processing by the integrated data processing computer 12 , the final detection result is obtained.

Further, a collimator (not shown in the figure) is set on the side where the first ray source 11, the second ray source 6, the third ray source 8, and the fourth ray source 15 emit X-rays, and the X-rays pass through. After the collimator it becomes a thin fan beam. The collimator is the prior art.

FIG. 2 shows the detection flow chart of the safety detection device according to the present invention, which first passes through the dual-energy spectrum CT detection device, and then passes through the multi-view detection device. S11 completes the acquisition of CT data, S12 performs data reconstruction, and obtains the tomographic structure information, tomographic electron density information, and tomographic effective atomic number information of the detected object 9; Connected region; in S14, analyze the electron density and effective atomic number of each independent connected region, query the database, and preliminarily determine the three-dimensional region of interest; S15 carry out data collection of the multi-view detection device, and in S16, carry out the image information obtained in S15. Segmentation to obtain a two-dimensional region of interest, combined with the CT tomographic information in S14; in S17, correct the effective atomic number of the three-dimensional region of interest to obtain the corrected effective atomic number information of each three-dimensional region of interest; finally, in S18 For the connected region of each three-dimensional region of interest, the information of the electron density obtained in S14 and the corrected effective atomic number information obtained in S17 are used to query the database to give the detection results, and display the detection results in the comprehensive data. process on the computer 12, and decide whether or not to alarm.

Example 2

As shown in FIG. 3 , the safety detection device of the present invention provides another embodiment, which is different from Embodiment 1 in that the detected object 9 is placed on the transmission device 16, and the transmission device 16 travels to the left, so The detected object 16 first passes through the multi-view detection device, and then passes through the CT detection device. FIG. 4 shows a working flow chart of the safety detection device shown in FIG. 3 . The CT detection device adopts a dual-energy spectrum CT detection device, and the specific process includes: completing multi-view X-ray data acquisition in S21; completing image segmentation in S22, and querying the database according to the effective atomic number information of each segmented area, and preliminarily determining Each two-dimensional region of interest; CT data acquisition is completed in S23, and three-dimensional reconstruction is performed on the collected CT data in S24 to obtain each CT tomographic structure information, tomographic electron density information and tomographic effective atomic number information; in S25, according to the information in S22 Two-dimensional region of interest, perform regional segmentation on each tomographic CT image information to obtain a three-dimensional connected region of interest corresponding to the multi-view two-dimensional region of interest; in S26, refer to the two-dimensional region of interest information of S22, Correct the effective atomic number of the region of interest, and obtain the corrected effective atomic number information of each three-dimensional region of interest; finally, for each three-dimensional region of interest in S27, according to the electron density information obtained in S24 and the corrected effective atom obtained in S26 For the ordinal information, the detection result is given by querying the database, and the detection result is displayed on the integrated data processing computer 12, and whether to alarm or not.

Example 3

As shown in FIG. 5 , the safety detection device of the present invention also provides another embodiment. The difference between this embodiment and Embodiment 1 is that the CT detection device adopts a single-energy spectrum CT detection device. The detection device adopts a detection method of first passing through a single-energy spectrum CT detection device and then passing through a multi-view detection device; specifically, it includes: S31 completes the acquisition of CT data, and in S32, CT three-dimensional reconstruction is performed to obtain tomographic structure information and tomographic electron density information, S33 performs regional segmentation on each tomographic CT image to obtain each independent connected area in the tomography, S34 refers to the electron density information, and preliminarily determines the three-dimensional region of interest by querying the database; in S35, the multi-view X-ray image information is completed by the multi-view detection device Acquisition; in S36, the image in S35 above is segmented to obtain a corresponding two-dimensional region of interest, and at the same time, combined with the CT tomographic information in S34, the effective atomic number calculation is finally performed on the three-dimensional region of interest in S37, and each three-dimensional sense of interest is obtained. The effective atomic number information of the region of interest; in S38, for each three-dimensional connected region of interest, and using the electron density information obtained in S34 and the effective atomic number information obtained in S37, the detection result is given by querying the database, and the The detection results are displayed on the integrated data processing computer 12, and it is decided whether or not to alarm.

Example 4

As shown in FIG. 6 , the safety detection device of the present invention also provides another embodiment. The difference between this embodiment and Embodiment 2 is that the CT detection device adopts a single-energy spectrum CT detection device. The detection device adopts the detection method of first passing through the multi-view detection device, and then passing through the single-energy spectrum CT detection device; specifically, it includes: S41 the multi-view detection device collects image data of the detected object 9, S42 divides the collected image information, and According to the effective atomic number information of each segmented area, query the database to preliminarily determine each two-dimensional area of interest, S43 collect data on the detected object 9, and in S44 obtain the CT tomographic structure information and tomographic electron density information of the detected object 9 , S45 performs regional segmentation on each tomographic CT image according to the two-dimensional region of interest determined in S42 to obtain each three-dimensional connected region of interest corresponding to the multi-view two-dimensional region of interest, and then combines the results of S42 in S46, Calculate the effective atomic number of the three-dimensional region of interest to obtain the effective atomic number information of each three-dimensional region of interest; in S47, for each three-dimensional connected region of interest, use the electron density information obtained in S44 and the effective atomic number obtained in S46. information, query the database, give the detection result, display the detection result on the integrated data processing computer 12, and decide whether to give an alarm or not.

Figures 7 and 8 of the safety detection device of the present invention show the calculation method of the effective atomic number. Further, in Figure 7, the CT detection device adopts a single-energy spectrum CT detection device, and the atomic number is corrected by the atomic number correction method. The information is corrected, the region of interest is obtained according to the three-dimensional tomographic structure information of the detected object, and the degree of object overlap in each projected viewing angle of the region of interest along the ray projection direction is analyzed to obtain the object overlap degree parameter at each viewing angle; When the detection device obtains 2-4 perspective projection perspectives, select the perspective with the smallest object overlapping degree parameter to calculate the effective atomic number. In FIG. 8 , the CT detection device adopts a multi-energy spectrum CT detection device, and the atomic number information is corrected by the atomic number correction method, the region of interest is obtained according to the three-dimensional tomographic structure information of the detected object, and the region of interest is analyzed. The degree of overlap between the region of interest and the metal object of each projection perspective along the ray projection direction is used to obtain the parameter of the overlap degree of the metal object in each perspective; when the multi-view detection device obtains 2-4 perspective projection perspectives, select the overlap degree of the metal object. The effective atomic number is calculated from the viewing angle with the smallest parameter.

As shown in Figures 9, 10 and 11, the calculation method of the object overlap degree parameter is given. Further, in Figure 9, the calculation method of the object overlap degree parameter includes normalizing the projected grayscale curve, As the probability density function of the position information, the mean square error under the probability density function is calculated as the value of the object overlap degree parameter; the larger the value, the lower the object overlap degree, and vice versa. Figure 10 shows another calculation method of the object overlap degree parameter. The region of interest of the detected object is located, the image value in the region of interest is set to 0, and then according to the multi-view angle direction and imaging geometry The parameters are orthographically projected to obtain the projected grayscale curve of the object after removing the region of interest, and the mean value of the projection data corresponding to the projection position of the region of interest is calculated as an overlap degree parameter. The smaller the mean, the smaller the overlap of objects. Fig. 11 shows the method for calculating the overlapping parameters of the metal objects, which includes: locating the region of interest of the detected object and determining the metal region inside the object by setting a threshold value. Set to 0, the image in the metal area is set to 1, and then perform orthographic projection according to the viewing angle direction and imaging geometric parameters of multiple viewing angles to obtain the projected grayscale curve of the object after removing the area of interest, and calculate the area of interest. The mean value of the projection data corresponding to the projection position is used as the overlap degree parameter. The smaller the mean, the smaller the overlap of objects.

The multi-view detector and ray source module of the present invention are all in the prior art, and are common detectors and ray source modules, and the number of multi-view detectors and ray source modules is combined according to actual needs, which can form CT detection Device and three-view detection device combined safety detection device, CT detection device and dual-view detection device combined safety detection device. In addition, the CT detection device, the multi-view detection device, the first control and data processing computer 10, the integrated data processing computer 12, and the second control and data processing computer 13 are also in the prior art, and the operator selects according to the actual situation.

The present invention is not limited to the above-mentioned embodiments, and any modifications, improvements and substitutions that can be conceived by those skilled in the art without departing from the essence of the present invention fall into the scope of the present invention.

Claims (10)

1. A safety detection method based on a safety detection device, wherein the safety detection device comprises a CT detection device, a transmission device and a multi-view detection device arranged on one side of the CT detection device, the CT detection device and the multi-view detection device share a detection channel, and the transmission device passes through the detection channel of the CT detection device and the detection channel of the multi-view detection device, and is characterized by comprising the following steps:

a. placing the detected object on an operating transmission device, and passing through the CT detection device; acquiring three-dimensional fault structure information, density information and atomic number information of the detected object, and acquiring an interested area of the detected object according to the density information and the atomic number information;

b. the detected object passes through a multi-view detection device to obtain perspective image information of the detected object from multiple views; meanwhile, obtaining effective atomic number information of the region of interest by combining the three-dimensional fault structure information in the step a; or correcting the atomic number information by an atomic number correction method to obtain effective atomic number information;

c. and obtaining the density information and the effective atomic number information of the detected object, and determining whether to give alarm information or not by searching a database.

2. A safety detection method based on a safety detection device, wherein the safety detection device comprises a CT detection device, a transmission device and a multi-view detection device arranged on one side of the CT detection device, the CT detection device and the multi-view detection device share a detection channel, and the transmission device passes through the detection channel of the CT detection device and the detection channel of the multi-view detection device, and is characterized by comprising the following steps:

a. placing the detected object on an operating transmission device, and passing through the multi-view detection device; obtaining perspective image information and atomic number information of a detected object from multiple visual angles, and obtaining an interested area of the detected object according to the perspective image information and the atomic number information of the detected object from multiple visual angles;

b. the detected object passes through a CT detection device to obtain three-dimensional fault structure information, density information and atomic number information of the detected object; simultaneously combining the perspective image information and the atomic number information in the step a to obtain effective atomic number information of the interested area; or correcting the atomic number information by an atomic number correction method to obtain effective atomic number information;

c. and obtaining the density information and the effective atomic number information of the detected object, and determining whether to give alarm information or not by searching a database.

3. The security inspection method according to claim 1 or 2, wherein when the CT inspection apparatus employs a single-spectrum CT inspection apparatus, the atomic number information is corrected by an atomic number correction method, comprising the steps of:

1) obtaining an interested area according to the three-dimensional fault structure information of the detected object, and analyzing the overlapping degree of the object of each projection view angle of the interested area along the ray projection direction to obtain the overlapping degree parameter of the object under each view angle;

2) and under the condition that the multi-view detection device obtains 2-4 perspective projection views, selecting the view with the minimum object overlapping degree parameter to calculate the effective atomic number.

4. The security inspection method according to claim 1 or 2, wherein when the CT inspection apparatus employs a multi-energy spectrum CT inspection apparatus, the atomic number information is corrected by an atomic number correction method, comprising the steps of:

1) obtaining an interested area according to the three-dimensional fault structure information of the detected object, analyzing the overlapping degree of the interested area and the metal object at each projection view angle of the interested area along the ray projection direction, and obtaining the overlapping degree parameter of the metal object at each view angle;

2) and under the condition that the multi-view detection device obtains 2-4 perspective projection views, selecting the view with the minimum metal object overlapping degree parameter to calculate the effective atomic number.

5. The security detection method of claim 3, wherein the calculation of the object overlap parameter comprises the steps of:

normalizing the projection gray curve, taking the projection gray curve as a probability density function of position information, and calculating the mean square error under the probability density function as the numerical value of an object overlapping degree parameter; or positioning the region of interest of the detected object, setting the image value in the region of interest to be 0, then carrying out orthographic projection according to the view angle direction of multiple viewing angles and imaging geometric parameters to obtain an object projection gray curve with the region of interest removed, and calculating the mean value of projection data of the projection position corresponding to the region of interest as an overlapping degree parameter.

6. The security inspection method of claim 4, wherein said method of calculating a metal object overlap parameter comprises the steps of:

positioning an interested region of an object to be detected, determining a metal region in the interested region and determining the metal region by setting a threshold value, setting an image in the interested region and outside the metal region as 0, setting an image in the metal region as 1, then carrying out orthographic projection according to the view angle direction of multiple view angles and imaging geometric parameters to obtain an object projection gray curve with the interested region removed, and calculating the mean value of projection data of the corresponding projection position of the interested region as an overlapping degree parameter.

7. A safety inspection apparatus for implementing the safety inspection method according to claim 1 or 2, comprising a CT inspection apparatus, a transmission apparatus, and a multi-view inspection apparatus disposed at one side of the CT inspection apparatus, wherein the CT inspection apparatus and the multi-view inspection apparatus share an inspection channel, and the transmission apparatus passes through the inspection channel of the CT inspection apparatus and the inspection channel of the multi-view inspection apparatus;

the CT detection device is connected with a first control and data processing computer; the multi-view detector and the ray source module are arranged in the multi-view detection device, and the multi-view detector is connected with the second control and data processing computer; the first control and data processing computer and the second control and data processing computer are connected with the comprehensive data processing computer.

8. The security detection apparatus of claim 7, wherein:

the CT detection device comprises a CT ray source module, a CT frame and a CT detector, wherein the CT ray source module and the CT detector are arranged on the CT frame; the CT detector is any one of a single-layer detector, a double-interlayer detector and a photon counting detector.

9. The security detection apparatus of claim 7 or 8, wherein:

the CT detection device is any one of a single-energy spectrum CT detection device and a multi-energy spectrum CT detection device.

10. The security detection apparatus of claim 7, wherein:

the multi-view detector is any one of a single-layer detector, a double-interlayer detector and a photon counting detector.

Images