CN102095664B - Method and device for checking liquid article - Google Patents

Abstract

The invention discloses a method and device for checking a liquid article by a dual-energy CT (computed tomography). The method comprises the following steps: carrying out DR (data recording) scanning on the liquid article to obtain a transmission image of the liquid article to be checked; analyzing the pixel values of the transmission image to determine whether the transmission image is laminated or not; carrying out dual-energy CT scanning on the liquid article to be checked at one or more than one positions in each layer to obtain dual-energy CT projection data; carrying out CT rebuilding according to the projection data to obtain a CT image indicating physical attribute values of the liquid article to be checked; extracting the physical attribute values of the liquid article according to the CT image; and judging whether the liquid article is counterfeit based on the physical attribute values and the reference physical attribute values of the liquid article. By applying the invention, the liquid article can be rapidly checked.

Description

Liquid article examination method and equipment

The application submitted to the dividing an application of No. 200710180653.2 application for a patent for invention that is entitled as " liquid article examination method and equipment " of Patent Office of the People's Republic of China on October 5th, 2007.

Technical field

The present invention relates to the radiation monitoring technical field, particularly a kind ofly carry out the method and apparatus that dual intensity CT imaging comes the liquid towards article fast and safely to check by the liquid towards article.

Background technology

After 911 events of the U.S. occured, the safety inspection work of aviation field more and more came into one's own.On the basis of the luggage parcel safety inspection of in the past carrying out, increased the safety inspection requirement of the liquid article that the passenger is carried.Therefore, be badly in need of the fast and safely inspection that effective mode and means are carried out liquid article in the luggage and articles.

Current, have the method for following four classes can be used for the safety inspection of liquid article: chemical method, electromagnetic method, submethod and ray method specifically describe as follows:

1) chemical method can be subdivided into odor identification, ion scan is surveyed and species analysis.Odor identification usually can't be realized because of the sealed packing of liquid article checking in actual applications.Ion scan is surveyed with hypersensitivity and is celebrated, but its shortcoming is that rate of false alarm is high, usually is subject to the impact of background environment.Species analysis has precision height and the high characteristics of accuracy, but this method needs the regular hour that sample is analyzed, and can not satisfy the on-the-spot demand that checks fast.

2) the electromagnetic method metering system of taking the initiative, thus it makes a distinction liquid article to electromagnetic specific inductive capacity is different according to different liquid articles.Electromagnetic method itself easily is subject to the adverse effect of mental package and thicker material packing.Therefore, under the actual conditions of wrappage complexity, electromagnetic method has certain limitation.

3) phenomenon of " neutron activation " can appear in the use of neutron inspection method, and namely the liquid article that is examined through the neutron inspection has the radiation residual phenomena.And, because the penetration capacity of neutron is stronger, therefore its radiation shield is more complicated, occupation area of equipment is large, thereby be not suitable in the safety check system of civil aviaton, using.

4) current, the safety inspection device of aviation field mostly is x-ray apparatus, and in these devices, adopting at present maximum technology is X ray two-dimensional imaging technology and three-D CT scanning imaging technique.These technology can obtain the structural information of object, but can't judge whether keep drugs in the liquid; This is because after keeping drugs in the liquid, just composition changes, and obvious variation can't occur general structure.

In sum, check fast for liquid article, chemical method, electromagnetic method and middle submethod exist the characteristics that itself are not suitable for fast and safely checking, adopt X ray two-dimensional imaging technology and three-D CT scanning imaging technique, can only obtain to comprise the image of structural information, can not be for judging whether liquid article keeps drugs abundant foundation is provided.

Summary of the invention

In order to overcome above-mentioned the deficiencies in the prior art, the purpose of this invention is to provide a kind of method and apparatus with safety-checking liquid stage article with ray, it can in the situation that do not destroy liquid article packing it is checked fast, obtain being examined the quantitative information of liquid article.

In one aspect of the invention, propose a kind of method that checks with dual intensity CT liquid towards article, comprised step: carried out the transmission image that DR scanning obtains tested liquid article for liquid article; Analyze the pixel value of described transmission image, to determine the whether layering of described transmission image; The dual intensity CT scan is carried out to tested liquid article at least one position in determined each layer, obtains dual intensity CT data for projection wherein, and described dual intensity CT scan adopts the mode of plane fault CT scan; Carry out CT according to described data for projection and rebuild, obtain representing the CT image of the physical property values of tested liquid article; Extract the physical property values of tested liquid article according to described CT image; And judge based on the reference physical property values of described physical property values and this liquid article whether suspicious described tested liquid article is.

According to embodiments of the invention, described physical property values comprises density and the atomic number of tested liquid article.

According to embodiments of the invention, the middle row in each layer is appointed as the position that will carry out the dual intensity CT scan.

According to embodiments of the invention, obtain transmission image after, by image processing techniques automatically determine each layer in the transmission image in the middle of row, as the CT scan position.

According to embodiments of the invention, carry out the step that DR scanning obtains the transmission image of tested liquid article for liquid article and comprise: send high-energy ray and low energy ray from radiographic source, penetrate tested liquid article, form high energy transmission image and low energy transmission image; Merge high energy transmission image and low energy transmission image, form described transmission image.

According to embodiments of the invention, carry out the step that DR scanning obtains the transmission image of tested liquid article for liquid article and comprise: send high-energy ray and low energy ray from radiographic source, penetrate tested liquid article, form high energy transmission image and low energy transmission image; Select one of high energy transmission image and low energy transmission image, as described transmission image.

According to embodiments of the invention, rebuild according to described data for projection, obtain representing that the step of CT image of the physical property values of tested liquid article comprises: according to high low energy data for projection, generate the data for projection about two kinds of sill coefficients; Data for projection according to described two kinds of sill coefficients is rebuild, and obtains representing the CT image of the corresponding two kinds of sill coefficients of tested liquid article; And according to described expression sill coefficient CT image, generate the CT image of the tested liquid article physical property values of described expression.

According to embodiments of the invention, the step of extracting tested liquid article physical property values according to described CT image comprises: extract the pixel corresponding with the liquid part from described CT image; To pixel bulk density average and the atomic number average of liquid part, as density and the atomic number of described tested liquid article.

According to embodiments of the invention, judge based on the reference physical property values of described physical property values and this liquid article whether suspicious step comprises described tested liquid article: the difference between bulk density and atomic number and reference density and the atomic number; In the situation of described difference greater than predetermined threshold value, think and hidden drugs in the described tested liquid article.

According to embodiments of the invention, after carrying out the dual intensity CT scan for each position, rotation is examined the CT image of liquid article, makes itself and the formed image alignment of the dual intensity CT scan first time.

According to embodiments of the invention, after carrying out the dual intensity CT scan for each row, rotate tested liquid article, make it identical with the position before the scanning.

According to embodiments of the invention, described liquid article is placed in the bucket that has been divided into a plurality of spaces.

According to embodiments of the invention, described method comprises step: utilize predetermined template automatically to detect the existence of bucket; In the situation that there is bucket, detect the specific markers in the CT image; Based on described specific markers, bucket is rotated to preposition.

According to embodiments of the invention, described method also comprises step: with the judgment result displays of tested liquid article on display screen.

According to embodiments of the invention, described method also comprises step: the judged result of each tested liquid article is printed.

According to embodiments of the invention, described method also comprises step: with the CT image color of each tested liquid article.

In another aspect of this invention, proposed a kind of equipment that checks with dual intensity CT liquid towards article, having comprised: radiographic source is used for sending ray; Survey and harvester, be used for surveying and gathering the ray signal that penetrates at least one tested liquid article; Controller is controlled described radiographic source and detection and harvester tested liquid article is carried out DR scanning, obtains the transmission image of tested liquid article; Analyze the pixel value of described transmission image, to determine the whether device of layering of described transmission image, wherein said controller is controlled described radiographic source and detection and harvester at least one position in determined each layer tested liquid article is carried out the dual intensity CT scan, obtain dual intensity CT data for projection, wherein, described dual intensity CT scan adopts the mode of plane fault CT scan; Described equipment also comprises: the device of rebuilding the CT image of the physical property values that represents tested liquid article from data for projection; And judge whether suspicious device of described tested liquid article based on the reference physical property values of described physical property values and this liquid article.

According to embodiments of the invention, described physical property values comprises density and the atomic number of tested liquid article at least.

According to embodiments of the invention, send high-energy ray and low energy ray from radiographic source, penetrate tested object, form high energy transmission image and low energy transmission image, described equipment also comprises: merge the device that high energy transmission image and low energy transmission image form described transmission image.

According to embodiments of the invention, send high-energy ray and low energy ray from radiographic source, penetrate tested object, form high energy transmission image and low energy transmission image, described equipment also comprises: select one of high energy transmission image and low energy transmission image, as the device of described transmission image.

According to embodiments of the invention, the middle row in each layer is appointed as the row that will carry out the dual intensity CT scan.

According to embodiments of the invention, the device of CT image of rebuilding the physical property values of the tested liquid article of expression from data for projection comprises: merge density image that the density by tested liquid article identifies and the atomic number image that identified by the atomic number of tested liquid article as the device of described CT image; From described CT image, extract the device of the pixel corresponding with the liquid part; To the pixel bulk density average of liquid part and atomic number average as the density of described tested liquid article and the device of atomic number.

According to embodiments of the invention, judge based on the reference physical property values of described physical property values and this liquid article whether suspicious device comprises described tested liquid article: the device of the difference between bulk density and atomic number and reference density and the atomic number; In the situation of described difference greater than predetermined threshold value, think and hidden drugs in the described tested liquid article.

According to embodiments of the invention, described equipment also comprises: after carrying out the dual intensity CT scan for every row, rotation is examined the CT image of liquid article, makes itself and the device of the formed image alignment of dual intensity CT scan for the first time.

According to embodiments of the invention, described equipment also is included in for each row and carries out rotating tested liquid article after the dual intensity CT scan, makes the identical device in position before itself and the scanning.

According to embodiments of the invention, described equipment also comprises bucket, has been divided into a plurality of spaces, is respectively applied to place described liquid article.

According to embodiments of the invention, described equipment comprises: utilize predetermined template automatically to detect the device of the existence of bucket; In the situation that there is bucket, detect the device of the specific markers in the CT image; Based on described specific markers, bucket is rotated to the device of preposition.

According to embodiments of the invention, described equipment also comprises: display device shows the judged result of tested liquid article.

According to embodiments of the invention, described equipment also comprises: the device that the judged result of each tested liquid article is printed.

According to embodiments of the invention, described equipment also comprises: with the device of the CT image color of each tested liquid article.

According to embodiments of the invention, described equipment also comprises the load carrier that carries described tested liquid article, and described load carrier carries on the surface of described tested liquid article and is divided into the discernible a plurality of zones of operating personnel.

Utilize method and apparatus of the present invention, owing to adopting transmission image to carry out the dual intensity CT scan as guiding, when having improved detection speed, do not reduce Detection accuracy, and can also judge by transmission image whether liquid article exists interlayer.

In addition, by the density of measuring is compared with atomic number with reference density with atomic number, can judge whether tested liquid article (such as wine etc.) keeps drugs (such as cocaine etc.).

In addition, the operator can carry out the dual intensity CT scan in the position of any appointment, has made things convenient for the carrying out of check operation.In addition, the operator can add new tested class of liquids voluntarily according to concrete needs.

In addition, in the situation that the lattice bucket is adopted in many simultaneously detections, can determine easily it is that the tested liquid article of that part is suspicious.

Description of drawings

From the detailed description below in conjunction with accompanying drawing, above-mentioned feature and advantage of the present invention will be more obvious, wherein:

Fig. 1 is the structural representation according to the checkout facility of embodiment of the present invention;

Fig. 2 shows the structured flowchart of computer data processor 60 as shown in Figure 1;

Fig. 3 shows the structured flowchart according to the controller of first embodiment of the invention;

Fig. 4 shows the identification information of the various liquid articles of storage in database and the structure that attribute information adopts;

Fig. 5 is the schematic diagram for the relation of explanation DR imaging and CT imaging;

Fig. 6 shows an example of DR imaging results;

Fig. 7 shows another example of DR imaging results;

Fig. 8 shows the overview flow chart according to the liquid article examination method of first embodiment of the invention;

Fig. 9 shows the process flow diagram of DR imaging process;

Figure 10 shows in the DR imaging process and to survey and the arrangement mode of the DR view data that harvester 30 gathers;

Figure 11 shows the DR image is processed to determine the process flow diagram of CT scan position;

Figure 12 shows the CT imaging process;

Figure 13 shows the arrangement mode of CT data for projection in the CT imaging process;

Figure 14 shows the process of measuring the liquid attribute;

Figure 15 shows the process that database is expanded;

Figure 16 A and Figure 16 B show the schematic diagram of the CT image of rebuilding in the situation according to many liquid articles of detection of second embodiment of the invention;

Figure 17 A shows after the CT imaging is finished to 17K, how CT reconstructed image and/or load carrier is rotated its process consistent with the relative position of object before the CT scan that make;

Figure 18 shows in the situation that many process flow diagrams that tested object checks;

Figure 19 shows the vertical view according to the load carrier of second embodiment of the invention;

Figure 20 shows the side view according to the lattice bucket of present embodiment;

Figure 21 shows the vertical view of lattice bucket;

Figure 22 shows the backplan of lattice bucket;

Figure 23 shows the process that how automatically to detect lattice bucket and mark in checking process;

Figure 24 A shows the schematic diagram of rotary barrel in testing process to 24D;

Figure 25 shows the process flow diagram according to the checking process of the 3rd embodiment;

Figure 26 A is the change curve of explanation liquid density after having hidden drugs;

Figure 26 B is the change curve of explanation liquid atomic number after having hidden drugs;

Figure 26 C is the change curve of explanation liquid characteristic density after having hidden drugs;

Figure 27 describes the process flow diagram of the inspection method of the 4th invention embodiment in detail;

Figure 28 is the schematic diagram that explanation liquid towards article carry out Spiral CT scan;

Figure 29 A is that explanation liquid towards article carry out the resulting image of Spiral CT scan to 29M.

Embodiment

Below, describe with reference to the accompanying drawings preferred implementation of the present invention in detail.In the accompanying drawings, although be shown in the different accompanying drawings, identical Reference numeral is used for representing identical or similar assembly.For clarity and conciseness, the detailed description that is included in the known function and structure here will be omitted, otherwise they will make theme of the present invention unclear.

[the first embodiment]

Fig. 1 is the structural representation according to the checkout facility of embodiment of the present invention.

As shown in Figure 1, the checkout facility according to present embodiment comprises: send the radiographic source 10 that checks with dual-energy x-ray, such as X-ray machine; Load carrier 40, it carries tested liquid article and rotates around axle Z, and can lifting, so that tested liquid article enters surveyed area, thereby can see through tested liquid article by the ray that radiographic source 10 sends; Survey and harvester 30, it is detector and the data acquisition unit with integral module structure, be used for surveying the dual intensity ray of the tested liquid article of transmission, obtain simulating signal, and analog signal conversion is become digital signal, thereby the dispensing liquid article are for the scan-data of sigmatron and low energy X ray; Controller 50, it is used for the various piece synchronous working of control whole system; And computer data processor 60, it is used for processing the data that gathered by data acquisition unit, and the outgoing inspection result.

As shown in Figure 1, radiographic source 10 places load carrier 40 1 sides that can place tested liquid article, detection and harvester 30 place the opposite side of load carrier 40, comprise detector and data acquisition unit, are used for obtaining tested liquid article DR data and multi-angle projection data.Comprise data amplification wave-shaping circuit in the data acquisition unit, it can work in (electric current) integral way or pulse (counting) mode.Survey the data output cable of being connected with harvester and be connected with computer data processor 60, according to trigger command the data that gather are stored in the computer data processor 60.

In addition, checkout facility also comprises the tubular object passage 20 that is made of metal, and it is arranged on the load carrier 40, can shield the outside radiation of X ray.Tested liquid article is placed in the tested object passage.

Fig. 2 shows the structured flowchart of computer data processor 60 as shown in Figure 1.As shown in Figure 2, the data communication device that gathers of data acquisition unit is crossed interface unit 68 and bus 64 is stored in the storer 61.Store configuration information and the program of computer data processor in the ROM (read-only memory) (ROM) 62.Random access memory (RAM) 63 is used in the temporary various data of processor 66 courses of work.In addition, also store in the storer 61 be used to the computer program that carries out the data processing and database prepared in advance, this database stores the relevant information of various known liquid articles, information such as liquid title, kind and physical attribute, the property value such as density and atomic number that is used for the tested liquid article liquid that calculates with processor 66 compares.Internal bus 64 connects above-mentioned storer 61, ROM (read-only memory) 62, random access memory 63, input media 65, processor 66, display device 67 and interface unit 68.

After the operational order of user by input media 65 inputs such as keyboard and mouse, the instruction code instructs processor 66 of computer program is carried out predetermined data processing algorithm, after obtaining data processed result, it is presented on the display device 67 such as LCD display, perhaps directly with the formal output result of hard copy such as printing.

Fig. 3 shows the structured flowchart according to the controller of embodiment of the present invention.As shown in Figure 3, controller 50 comprises: control module 51, according to the instruction from computing machine 60, control radiographic source 10, load carrier 40 and detection and harvester 30; Trigger pip generation unit 52 is used for producing the trigger command of the action that is used for triggering radiographic source 10, detection and harvester 30 and load carrier 40 under the control of control module; The first drive motor 55, it drives load carrier 40 at the trigger command that produces according to trigger pip generation unit 52 and rises or descend under the control of control module 51; Elevation information acquiring unit 53, it is along with the motion of load carrier 40, to the elevation information of control module 51 feedback load carriers; The second drive motor 56, it drives load carrier 40 rotations at the trigger command that produces according to trigger pip generation unit 52 under the control of control module 51; Angle information acquiring unit 54, it obtains the anglec of rotation of load carrier 40 in load carrier 40 rotary courses, feed back to control module 51.

According to the embodiment of the present invention, above-mentioned elevation information acquiring unit 53 and angle information acquiring unit 54 all are photoelectric code disks, and it possesses jamproof advantage.

As mentioned above, in storer 61, store database, wherein stored identification information and the physical property values of known various liquid articles with tree structure, for example the reference density of liquid article and referencing atom ordinal number.Fig. 4 shows the identification information of the various liquid articles of storage in database and the structure that attribute information adopts.

For example all samples at first are divided into some subclasses, such as subclass 1 (wine), subclass 2 (cola), subclass 3 (milk) ... subclass n etc.Then, each subclass is subdivided into some subclasses.For example subclass 1 (wine) is subdivided into subclass 1.1 (grape wine), subclass 1.2 (Spirit), subclass 1.3 (beer) ..., subclass 1.n etc.Each subclass continues segmentation.Such as, subclass 1.2 (Spirit) be subdivided into subclass 1.2.1 (Rum), subclass 1.2.2 (whiskey), subclass 1.2.3 (vodka) ..., subclass 1.2.n (China white wine), until the difference of the reference density of inner each sample of subclass and atomic number is less than the value of a certain appointment, scope such as the systematic survey noise, then no longer segmentation, this group becomes the leaf node of attribute structure.

In addition, each leaf node identifies with the combination of its all father node titles, such as " Cuba produces 40 degree Havana anejo Rums ".This sign and reference density and referencing atom ordinal number are one to one.In check process, computing machine shows the user step by step with tree structure, and the operator inputs identification information by the mode of selecting step by step.Wish to obtain the physical attribute information that one bottle of Cuba produces 40 degree Havana anejo Rums such as, operator, can along wine-＞Spirit-＞Rum-＞Cuba's Rum-＞path of Havana anejo Rum-＞40 degree is selected step by step.

The operator also is the process of computer search by selecting step by step the process of input sign simultaneously, and when the user determined final sign, its corresponding reference density and atomic number also were retrieved simultaneously.

Fig. 5 is the schematic diagram for the relation of explanation DR imaging and CT imaging.First embodiment of the invention, at first the liquid towards article carry out the DR imaging, in order to judge the liquid part in the liquid article, then only carry out the CT imaging for certain position in the liquid part, in order to improve the speed that checks.

Fig. 6 and Fig. 7 show respectively the example of DR imaging.As shown in Figure 6, after certain liquid article is carried out the DR imaging, by the position of pixel value analysis being judged liquid in the liquid article as described below.As shown in Figure 6, only comprise a kind of liquid in this liquid article.But, as shown in Figure 7, because different liquids is different to the absorption coefficient of liquid, when liquid article comprises two kinds or two or more liquid, and when layering occurring in the liquid, judge interfacial position between the liquid by the DR image that obtains after the DR imaging being carried out pixel analysis.Then, carry out the CT imaging for different liquid.

Fig. 8 shows the overview flow chart according to the liquid article examination method of first embodiment of the invention.As shown in Figure 8, for example during being open to the custom, need to carry out safety inspection to the liquid article that the passenger carries.At first at step S110, the operator is placed on tested liquid article on the load carrier 40, and the identification information that obtains this liquid article according to passenger's customs declaration or the label on the liquid article, for example 40 degree rum.

Then, at step S111, the operator searches for from database according to this identification information and obtains its reference density and referencing atom ordinal number.Next, the operator presses start button and begins to carry out DR scanning, to generate the DR image, shown in Fig. 6 and 7.

As mentioned above, the purpose of carrying out DR scanning is: the one, obtain the fluoroscopy images of tested liquid article, and make the operator can see the inner structure of tested liquid clearly; The 2nd, software can according to DR image automatic identification liquid position, guide next step CT imaging; The 3rd, the user can specify the position that need to carry out CT imaging and inspection at the DR image, guides next step CT imaging.The back will be described the detailed process of DR imaging in detail.

Should be noted that, DR scanning is not necessary.In order to accelerate inspection speed, can not scan to guide CT scan by DR, but directly CT scan is carried out in predetermined some positions.Such as, through investigation, as can be known 5 centimetres at the distance bottle end carry out CT scan the time, can be checked through the liquid position of most of liquid commodity, then can use at the bottom of the bottle 5 centimetres height as predetermined scanning height.In addition, the operator can arrange suitable height by rule of thumb by range estimation checking matter size, is 3cm such as the scanning height that tank shape cola is set, and thicker scanning height vinous is 10cm at the bottom of arranging bottle.

After obtaining the DR image, at step S113A, the DR image is analyzed, automatically determine the scanning position (such as the position of arrow indication among Fig. 6 and Fig. 7) of CT imaging, perhaps at step S113B, specify the position that to carry out CT scan by the input media 65 of operator's operation such as mouse.Like this and since only in the liquid towards article representational position carry out CT scan, thereby accelerated inspection speed, do not check on the quality and can not reduce.

After the position of having determined CT scan, carry out the CT scan process at step S114, namely carry out CT scan for above-mentioned definite scanning position liquid towards article, obtain the CT scan data, and calculate CT image reconstruction according to rebuilding.Each pixel of this CT image has represented density and the atomic number of appropriate section in the liquid article.

Then, at step S115, computing machine is analyzed the CT image by execution analyzer, obtains density and the atomic number of measurement.And then, at step S116, the density measured and atomic number and the reference density of retrieving from database and atomic number are compared, judge whether the two is consistent with each other, for example whether the difference of the two is less than predetermined threshold value.At step S117, if difference shows then that greater than predetermined threshold value this liquid article is suspicious, send warning to the operator, perhaps print check result.

Describe the detailed operating process of above-mentioned each step in detail below in conjunction with accompanying drawing 9～14.Fig. 9 shows the process flow diagram of DR imaging process, and Figure 10 shows in the DR imaging process and to survey and the arrangement mode of the DR view data that harvester 30 gathers.

As shown in Figure 9, in the DR imaging process, at step S210,50 send order from computing machine 60 to controller, to drive load carrier 40 along 20 vertical movements of object passage.Controller 50 is in the process of load carrier vertical movement, by the height of elevation information acquiring unit 53 Real Time Monitoring load carriers.

At step S211, controller 50 is given every certain height (such as 1 millimeter) and is surveyed and trigger pip of harvester 30 transmissions.Survey and after harvester 30 receives this trigger pip, the output signal of each detector is once gathered, acquisition high energy detection data and low energy detection data, and be saved in its built-in impact damper.

At step S212, judge whether load carrier 40 reaches specified altitude assignment, such as 500 millimeters.If do not reach yet, then flow process forwards step S210 to, continues aforesaid operations.

If load carrier 40 arrives above-mentioned predetermined height, then controller 50 is no longer given and is surveyed and harvester 30 transmission trigger pips.Computing machine 60 reads the high low energy detector signal that collects from detection and harvester 30, be arranged as the form of data matrix, becomes the DR image.Each pixel of DR image has recorded ray and has penetrated remaining intensity behind the object, comprises low energy ray intensity and high-energy ray intensity.

As mentioned above, the scanning position of follow-up CT imaging is all determined at the DR image.No matter be to use the automatically mode of identification, or the mode of artificial appointment all is at first to obtain a line number at the DR image, and then computing machine is converted to the load carrier height with this line number, and after instruction control unit 50 drives load carriers 40 and move to assigned address, carry out again the CT imaging.

By DR imaging flow process as can be known, every delegation of DR image is corresponding to specific load carrier 40 height.The load carrier height value is 0 when supposing that the DR imaging process begins, and load carrier constantly descends in the imaging process, triggers once gathering every the h millimeter, and the m in the DR image is capable so, and its corresponding load carrier height is-m*h.

Figure 11 shows the DR image is processed to determine the process flow diagram of CT scan position.

In the DR image, at the bottom of tested liquid article generally is divided into bottle, several parts such as liquid part, bottleneck, bottle cap, liquid part (multilayer may be arranged) wherein can be extracted by image analysis technology, and determine each layer CT scan position.

At step S310, the high low energy data of DR image are merged and level and smooth, obtain the less monodrome DR image of noise.For example, the concrete grammar that high low energy merges can be directly to select a kind of as fusion results in the high low energy data, also can be the weighted array of high low energy data.Level and smooth method can be to use Gaussian filter that image is carried out filtering to process.

At step S311, extract the tested liquid article (prospect) in the level and smooth rear DR image, remove air (background).Concrete grammar can be to set a threshold value, and value is classified as foreground pixel in this pixel below threshold value, and other pixels are classified as background pixel.The reason that adopts threshold value to remove background is: tested liquid article has blocked ray, so its corresponding DR pixel value lower (DR recording image be the residual intensity of ray).

At step S312, extract the horizontal edge pixel in the level and smooth rear DR image.Concrete grammar can be: to each pixel of DR image, calculate the difference value of neighbor on itself and the vertical direction; If this difference value arrives greatly certain more than the threshold value, just think that this pixel belongs to the horizontal edge pixel.

At step S313, extract level and smooth after horizontal edge in the DR image capable, horizontal edge is capable of the interface between the multilayer liquid at the bottom of the bottle and in the interface of the interface of the interface of liquid, liquid and air, bottle cap and air or the container.Concrete grammar can be: to every delegation of along continuous straight runs in the DR image, add up the ratio of its horizontal edge number of picture elements and foreground pixel number, if ratio arrives greatly certain threshold value above (such as 50%), then this delegation is classified as horizontal edge capable.

At step S314, the DR image is carried out vertical partitioning, and get rid of non-liquid regions.Each bar horizontal edge in the DR image is about to the DR image and has been divided into a plurality of zones, comprises successively from the bottom up: air (if any), bottle cap etc. in the bottle end, liquid (according to the difference of density, multilayer may be arranged), the bottle.By formulating filter criteria, can get rid of the on-liquid zone, concrete criterion as:

A) in vertical direction, line number is got rid of less than the zone of a certain threshold value.The zone that line number is less, the very little zone of thickness namely, might be bottle at the bottom of, narrow and small space (such as the air of pop can inner top) between bottle cap or liquid in container and the container top.Determining of concrete threshold value can be determined by air layer thickness in the bottle end, bottle cap and the container of investigating various liquid package containers.

B) in the horizontal direction, the average foreground pixel number of each row is got rid of less than the zone of certain threshold value.These zones are often corresponding to elongated bottleneck.Determining of concrete threshold value can be determined by realizing the width that obtains various liquid package container bottlenecks.

At step S315, determine the CT scan position of liquid regions (may have a plurality of), finish the Hierarchical Location of liquid.After getting rid of the on-liquid zone, remaining zone (may have a plurality of) is classified as liquid regions.Get the central row of these zones on short transverse, as the CT scan position.

Described above is the process of automatically determining the CT scan position.But in the situation that manual invisible scanning position, the operator will carry out the row of CT scan by input media 65 direct appointment on the DR image that shows, as the CT scan position.

Figure 12 shows the CT imaging process, and Figure 13 shows the arrangement mode of CT data for projection in the CT imaging process.

As shown in figure 12, after the position of having determined CT scan, carry out the CT imaging process, namely in performed CT scan position, carry out the CT imaging, generate density and atomic number image about a tomography of checking matter, to carry out the measurement of fluid density and atomic number.As mentioned above, owing to only CT scan is carried out in typical position, so can greatly save the time of being open to the custom.

At step S410, computing machine 60 sends order for controller 50, drives load carrier 40 rotation predetermined angulars, for example 1 degree.Controller 50 is in the process that load carrier rotatablely moves, by angle information acquiring unit 54 Real Time Monitoring load carrier angles.

At step S411, when turning over 1 degree, controller 50 is given and is surveyed and trigger pip of harvester 40 transmissions.Survey and after harvester 40 receives trigger pip, the output signal of each detector is once gathered, and be saved in its built-in impact damper.

Then, at step S412, judge whether the accumulative total rotational angle reaches a week.If do not reach a week, then flow process forwards step S410 to, continues above-mentioned operating process.

If after the accumulative total rotational angle reached specified angle (such as 360 degree), rotatablely moving at step S413 stopped, controller 50 is no longer given and is surveyed and harvester 30 transmission trigger pips.Computing machine 60 reads the high low energy detector signal that collects from detection and harvester 30, be arranged as the form of data matrix, becomes the CT data for projection, as shown in figure 13.Each pixel of CT data for projection has recorded ray and has penetrated remaining intensity behind the object, comprises low energy ray intensity and high-energy ray intensity.

At step S414, computing machine 60 utilizes the dual intensity reconstruction algorithm, according to high low energy CT data for projection, rebuilds the density and the atomic number image that obtain on the tomography, i.e. the CT image.Each pixel in the CT image has recorded tested object at density and the atomic number of this pixel correspondence position.

The following describes the process of rebuilding faultage image from high low energy CT data for projection.

● the CT mathematical principle

Two dimensional Distribution u (x, y) is asked line integral along certain direction θ, just obtain the function p of one dimension _θ(t), this function is called u (x, y) in the projection of θ angle.If can access the projection p of all directions _θ(t), can obtain Two dimensional Distribution u (x, y) according to Radon conversion accurate Calculation so.The process that obtains Two dimensional Distribution from projection is called reconstruction.

In the practical application, X-ray machine and detector are around object rotation one circle, and the attenuation coefficient that just measures certain section of object is distributed in the projection of all directions, thereby can rebuild the attenuation coefficient Two dimensional Distribution that obtains the object section according to the CT principle.

● the sill decomposition model

In the related energy range of small-sized X-ray safety inspection system (＜200keV), the material line attenuation coefficient can come approximate representation with following analytical expression (1).

μ(E)＝a ₁f _p(E)+a ₂f _KN(E)(1)

$a_1=\frac{\mathrm{\ρZ}}{M}{Z}^n---\left(2\right)$

$a_2=\frac{\mathrm{\ρZ}}{M}---\left(3\right)$

In the formula (1), f _p(E) expression photoelectric effect cross section is along with the variation relation of energy, f _KN(E) expression Compton scattering cross section is along with the variation of energy, f _p(E) and f _KN(E) known analytical expression is all arranged.Constant a ₁And a ₂Relevant with atomic number, mass number and the density of material, its expression formula is shown in (2) and (3) formula, and wherein Z represents atomic number, and M represents mass number, and ρ represents density (g/cm ³), n is constant.

Because the line attenuation coefficient of every kind of material can be by two coefficient a in the formula (1) ₁And a ₂Uniquely determine, therefore can choose two kinds of sills, such as carbon and aluminium, represent other all materials with the linear combination of the line attenuation coefficient of sill, shown in (4):

μ(E)＝b ₁μ ₁(E)+b ₂μ ₂(E)(4)

Wherein, μ (E) is the line attenuation coefficient of any one material, μ ₁(E) and μ ₂(E) be the line attenuation coefficient of selected two kinds of sills, b ₁And b ₂Be called the sill coefficient.

According to formula (5), 2 times of the definition atomic number is characteristic density with the ratio of mass number and the product of density.

${\mathrm{\ρ}}^{*}=\mathrm{\ρ}\frac{2Z}{M}---\left(5\right)$

Atomic number and the characteristic density of supposing two kinds of sills are respectively

With Can derive the expression formula of the atomic number of any one material and characteristic density according to top formula (1)～(4) so as follows:

${\mathrm{\&rho;}}^{*}={\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HSA00000409183700161.png,HSA00000409183700163.png"\; state="\{\{state\}\}">b</figure-callout>}}_1{\mathrm{\&rho;}}_1^{*}+b_2{\mathrm{\&rho;}}_2^{*}---\left(6\right)$

$Z={\left(\frac{{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HSA00000409183700161.png,HSA00000409183700163.png"\; state="\{\{state\}\}">b</figure-callout>}}_1{\mathrm{\&rho;}}_1^{*}{Z}_1^n+b_2{\mathrm{\&rho;}}_2^{*}{Z}_2^{\mathrm{<figure-callout\; id="1"\; label="n\; b"\; filenames="HSA00000409183700161.png,HSA00000409183700163.png"\; state="\{\{state\}\}">n</figure-callout>}}}{b_{}}\right)}^{1/n}---\left(7\right)$

● the sill projection model

The power spectrum that X-ray tube produces is generally continuous spectrum, and detector neither constant to the energy response function of X ray.Suppose power spectrum N (E) and energy response function P _d(E) product is S (E), and with S (E) normalization,

${\&Integral;}_0^{E_m}S\left(E\right)\mathrm{dE}=1---\left(8\right)$

The expression formula of the projection value on projection line is following integration type so:

$p=-\ln \frac{I}{I_0}=-\ln {\&Integral;}_0^{E_m}S\left(E\right)\exp (-\underset{l}{\&Integral;}\mathrm{\&mu;}(E,x,y)\mathrm{dl})\mathrm{dE}---\left(9\right)$

In the formula (9), I ₀Represent respectively ray by before the object decay and the detector readings value after the decay, E with I _mThe ceiling capacity of expression ray, l represents the path that ray passes.

Formula (9) is the relation of measurement projection value p and the Two dimensional Distribution μ (x, y) of real system.Can find out, because the X ray pleochroism, formula (9) does not represent μ (x, y) along the line integral of certain bar straight line, thereby does not satisfy the requirement of CT mathematical principle.Conventional reconstruction algorithm is ignored this inconsistency, rebuilds the pseudo-shadow that μ (x, the y) image that obtains contains cup-shaped, is called the pseudo-shadow of sclerosis.

Existing dual intensity CT method adopts first conventional reconstruction algorithm to obtain two groups of μ (x, y), then calculates the information such as atomic number and density.But can not eliminate so the pleochromatic impact of ray.The thinking that the present invention adopts sill to decompose has solved this problem.

The sill decomposition model is updated in the formula (9), can obtains the projection value expression formula based on the sill coefficient:

$p=-\ln {\&Integral;}_0^{E_m}S\left(E\right)\exp (-{\&Integral;}_l[{\mathrm{\&mu;}}_1\left(E\right)b_1(x,y)+{\mathrm{\&mu;}}_2\left(E\right)b_2(x,y)\left]\mathrm{dl}\right)\mathrm{dE}---\left(10\right)$

The integration along path l in the following formula is expressed with following formula:

∫ _lb ₁(x，y)dl＝B ₁(11)

∫ _lb ₂(x，y)dl＝B ₂(12)

According to above-mentioned (11), the definition of (12) two formulas, claim B ₁And B ₂Be sill coefficient b ₁(x, y) and b ₂The projection of (x, y).Supposed to get access to the complete sill coefficient projection under each angle, so just can rebuild according to the CT reconstruction theory and obtain sill coefficient b ₁And b ₂Distribution, thereby calculate the atomic number of object and characteristic density distributes according to the sill decomposition model, and any line attenuation coefficient value under the energy.

● finding the solution of sill coefficient projection

Dual intensity CT is recording projection data under two energy, just obtains following dual intensity data for projection:

$p_1({\mathrm{<figure-callout\; id="1"\; label="B"\; filenames="HSA00000409183700161.png,HSA00000409183700163.png"\; state="\{\{state\}\}">B</figure-callout>}}_1,B_2)=-\ln {\&Integral;}_0^{E_1}{S}_1\left(E\right)\exp [-{\mathrm{<figure-callout\; id="1"\; label="B"\; filenames="HSA00000409183700161.png,HSA00000409183700163.png"\; state="\{\{state\}\}">B</figure-callout>}}_1{\mathrm{\&mu;}}_1\left(E\right)-B_2{\mathrm{\&mu;}}_2\left(E\right)]\mathrm{dE}---\left(13\right)$

$p_2({\mathrm{<figure-callout\; id="1"\; label="B"\; filenames="HSA00000409183700161.png,HSA00000409183700163.png"\; state="\{\{state\}\}">B</figure-callout>}}_1,B_2)=-\ln {\&Integral;}_0^{E_2}{S}_2\left(E\right)\exp [-{\mathrm{<figure-callout\; id="1"\; label="B"\; filenames="HSA00000409183700161.png,HSA00000409183700163.png"\; state="\{\{state\}\}">B</figure-callout>}}_1{\mathrm{\&mu;}}_1\left(E\right)-B_2{\mathrm{\&mu;}}_2\left(E\right)]\mathrm{dE}---\left(14\right)$

Measuring (p ₁, p ₂) after, can find the solution according to equation (13) and (14) and obtain (B ₁, B ₂).But because above-mentioned two equations are the logarithmic integral equation, can't Analytical Solution.The common calculated amount of Iterative solution method for nonlinear equation is very large, and is not easy to obtain stable solution.

Noticing, is d when ray passes thickness ₁And d ₂Sill 1 and 2 after, the dual intensity projection that measures such as following expression formula:

${\mathrm{<figure-callout\; id="1"\; label="p"\; filenames="HSA00000409183700161.png,HSA00000409183700163.png"\; state="\{\{state\}\}">p</figure-callout>}}_1=-\ln {\&Integral;}_0^{E_1}{S}_1\left(E\right)\exp [-{\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="HSA00000409183700161.png,HSA00000409183700163.png"\; state="\{\{state\}\}">d</figure-callout>}}_1{\mathrm{\&mu;}}_1\left(E\right)-d_2{\mathrm{\&mu;}}_2\left(E\right)]\mathrm{dE}---\left(15\right)$

$p_2=-\ln {\&Integral;}_0^{E_2}{S}_2\left(E\right)\exp [-{\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="HSA00000409183700161.png,HSA00000409183700163.png"\; state="\{\{state\}\}">d</figure-callout>}}_1{\mathrm{\&mu;}}_1\left(E\right)-d_2{\mathrm{\&mu;}}_2\left(E\right)]\mathrm{dE}---\left(16\right)$

Contrast (13), (14) and (15), (16) can find out, the data for projection of supposing to measure is to (p ₁, p ₂) identical, the sill data for projection is to (B so ₁, B ₂) with the thickness of sill combination (d ₁, d ₂) be identical.

Measure the dual intensity projection under the different-thickness combination, just can obtain the dual intensity data for projection to (p ₁, p ₂) with sill coefficient data for projection to (B ₁, B ₂) corresponding relation, form look-up table.According to (p ₁, p ₂) calculating (B ₁, B ₂) just can be according to look-up table, utilize linear interpolation to realize, replace complicated solution procedure.

Figure 14 shows the process of measuring the liquid attribute.

As shown in figure 14, at step S510, density image and atomic number image are merged with level and smooth, obtain the less monodrome CT image of noise.The concrete grammar that merges can be directly to select a kind of as fusion results in density image and the atomic number image, also can be both weighted array.Level and smooth method can be to use Gaussian filter that image is carried out filtering to process.

At step S511, extract the checking matter (prospect comprises liquid and packing thereof) in the level and smooth rear CT image, remove air (background).Concrete grammar can be to set a threshold value, and value is classified as foreground pixel in this pixel more than threshold value, and other pixels are classified as background pixel.This is that the density of tested liquid article and atomic number are then relatively large because density and the atomic number of air are almost 0.

At step S512, extracting liq pixel in foreground pixel.Concrete grammar can be: one of model and bianry image corresponding to CT figure, and the value of foreground pixel is 1, the value of background pixel is 0; Then this bianry image is carried out repeatedly erosion operation, corrode a pixel at every turn, value is that 1 pixel is the liquid pixel at last.This is because liquid always in the inside of packing material, can be removed packing material step by step by repeatedly corroding.The number of times of corrosion can be set by realizing the thickness of determining packing material.

At step S513, average density and the average atomic number of all liq pixel among the statistics CT figure are as the Output rusults of this measurement.

In addition, if determine that in the DR image analysis process liquid state is layering, then carries out aforesaid step for every layer of liquid, and then judges whether suspicious each layer liquid is.Finally, report final check result to the operator.

In addition, exist the liquid article information in the database not enough, the situation that need to expand.In other words, the every data content in the database can be filled by supplier before system dispatches from the factory by producer, also allows that the operator expands database after system dispatches from the factory simultaneously.For example occurred in a kind of situation of new beverage in the market, the operator can be from reference density and the referencing atom ordinal number of this beverage of Sample producing of this beverage.Figure 15 shows the process that database is expanded.

The basic skills of filling a record in database is: at first survey test sample and determine its reference density and atomic number, then set up a unique sign at tree-shaped tag system for it, and sign, reference density and atomic number are deposited in the database together according to sign.

As shown in figure 15, at step S610, the operator powers on to system, and the log database Expansion Interface.Enter ready state behind the System self-test.The operator is placed on the fluid sample that hope is added in the database on the load carrier 40.At step S611,50 give an order from computing machine 60 to controller, trigger radiographic source 10 and detection and harvester 30 and carry out the DR imaging, and step S612A as described above mode automatically determine liquid position or also can on DR figure, manually specify liquid position step S612B operator.

At step S613, carry out the CT imaging at automatic or manual definite liquid position, and analyze the CT image with reference density and atomic number from CT Image Acquisition liquid at step S614.

Then, at step S615, the operator sets a sign to fluid sample, such as Coca-Cola, then after step S616 is with fluid identification and its reference density and atomic number binding, is saved in the database.

[the second embodiment]

What the first top embodiment was described is the situation that at every turn detects the single-piece liquid article, describes the operating process that detects simultaneously many liquid articles in detail below in conjunction with Figure 16～19.The difference of the second embodiment and the first embodiment is, because there are many liquid articles, need to be after the CT imaging be finished, the position of the object on the position of the imaging results that display shows and load carrier is corresponding, thereby convenient operation person understands fully that part liquid article is suspicious.Figure 16 A and Figure 16 B show the schematic diagram of the CT image of rebuilding in the situation according to many liquid articles of detection of second embodiment of the invention.

For example, the operator observes checking matter on the load carrier in the mode of overlooking, and the position of each object must be consistent with load carrier 40 vertical views on each layer CT image after this just required to check and finishes.

Figure 17 A-17K shows after the CT imaging is finished, and how CT reconstructed image and/or load carrier is rotated its process consistent with the relative position of object before the CT scan that make.

Figure 17 A showed when the first time, the CT imaging began, and the vertical view of load carrier 40 is wherein with the angle of arrow indication load carrier.Figure 17 B shows the CT image before first time CT image rotation, and the vertical view of the load carrier when it begins with for the first time imaging is consistent, the rotating range of dotted line sign load carrier wherein.Figure 17 C shows the image behind ground floor CT image rotation, because the anglec of rotation is zero, therefore in fact need not this layer CT image is rotated.

Figure 17 D shows when the n time CT imaging begins, the vertical view of load carrier.From Figure 17 D, can find out, when the n time CT imaging begins, the situation of load carrier before the CT imaging first time, with an angle.Figure 17 E shows the image before the n time CT image rotation, and the vertical view of load carrier was consistent when it began with the n time imaging.Figure 17 F shows the image among Figure 17 D is rotated, and makes the schematic diagram of itself and ground floor CT image alignment.

Figure 17 G shows when the CT imaging begins the last time, the vertical view of load carrier, the load carrier that can find out this moment when the CT imaging begins than the first time with an angle.Figure 17 H shows the image before the N time CT image rotation, and the vertical view of load carrier was consistent when it began with the N time imaging.Figure 17 I shows the image among Figure 17 H is rotated, and makes the schematic diagram of itself and ground floor CT image alignment.

After Figure 17 J shows last CT imaging end, the vertical view of load carrier, the situation before wherein beginning than the CT imaging first time has an anglec of rotation.Figure 17 K shows rear load carrier is rotated of imaging end and makes it consistent with the image that for the first time CT imaging obtains.

After all CT imaging processes finish, each layer CT image and load carrier are carried out angular setting one time.At first, load carrier angle when imaging begins according to each time CT (this angle can obtain by angle information acquiring unit 54), each layer CT image is rotated processing, the position of same object in each layer CT image is consistent, such as snapping to ground floor CT.Then, adjust the angle of load carrier, the vertical view of load carrier and CT image are consistent.

For example, suppose to have carried out altogether N CT imaging, the load carrier angle was α when the n time CT imaging began _n, the load carrier angle is β during end _n, load carrier is counterclockwise to rotate on vertical view.For the position of the position of object in n layer CT image on all with the 1st layer is consistent, only need n layer CT image by anglec of rotation α counterclockwise _n-α ₁Get final product.Behind the image rotating, be consistent at load carrier vertical view and CT figure in order to make object, only need load carrier by counter clockwise direction anglec of rotation 360-(β _N-α ₁) get final product.

Figure 18 shows in the situation that many process flow diagrams that tested object checks.As shown in figure 18, at step S710, the operator powers on to system, and login inspection interface, enters ready state behind the System self-test.Then, the operator is with many checking matters, and for example object A and object B are placed directly on the load carrier 40 and press the inspection knob.Here, suppose that object A is placed on the position, the upper right corner of load carrier, and object B is placed on the position, the lower left corner of load carrier.In addition, the operator inputs object A and object B identification information separately.

At step S711, from database, retrieve separately reference density and referencing atom ordinal number based on the identification information of object A and object B.Next, at step S712, the operator presses start button and begins according to carrying out DR scanning with identical as mentioned above mode, to generate the DR image.

After obtaining the DR image, at step S713A, the DR image is analyzed, automatically determine the scanning position of CT imaging, perhaps at step S713B, specify the position that will carry out CT scan by the input media 65 of operator's operation such as mouse.Like this and since only in the liquid towards article representational position carry out CT scan, thereby accelerated inspection speed, do not check on the quality and can not reduce.

After the position of having determined CT scan, carry out the CT scan process at step S714, namely carry out CT scan for above-mentioned definite position liquid towards article, obtain the CT scan data, and according to the reconstruction algorithm CT image reconstruction.Each pixel of this CT image has represented density and the atomic number of appropriate section in the liquid article.Exist when liquid in the situation of multilayer, carry out CT scan for each layer.

At step S715 and S716, after last CT imaging finishes, method is adjusted load carrier angle and each layer CT image angle as described above, the position of each object in each layer CT image is consistent (such as alignment ground floor CT), be consistent (such as consistent with vertical view) with the physical location of object on load carrier simultaneously, so that distinguish object B and object A.

At step S717, every layer of CT image carried out image segmentation process (such as using watershed algorithm), obtain the wherein liquid regions of every checking matter, the density of each pixel and atomic number average in step S718 adds up each liquid regions, compare with reference density and atomic number at step S719 and with it, whether suspiciously differentiate this layer liquid of this part checking matter at step S720 accordingly.

At step S721, gather each layer inspection conclusion and be prompted to the operator.A kind of method of summary is: only when all liq zone all was judged to safe liquid in all CT images, the conclusion of this inspection was " safety "; Otherwise the conclusion of this inspection is " suspicious ".In addition, every layer of CT image carried out the colorize processing and be shown to the user, the checking matter that is judged to suspicious object among the CT figure uses a kind of color (such as redness), is judged to the another kind of color (such as green) of use of safe liquid.

Described above is the situation that checks simultaneously two liquid articles, in the time will checking more liquid articles simultaneously, see the position of understanding each liquid article for the ease of operating personnel, as shown in figure 19, mark off a plurality of zones on the surface to load carrier carrying liquid article, for example the A district among Figure 19, B district, C district and D district, operating personnel can be placed on each part liquid article in the corresponding zone like this, and input separately fluid identification information for regional.

[the 3rd embodiment]

Easily produce unstable when causing detecting on the load carrier and impact detects the problem of effect in order further to improve detection efficiency and to prevent that elongated tested liquid article from directly placing, the 3rd embodiment proposes many objects are placed in the lattice bucket.

Therefore, the difference of the 3rd embodiment and the second embodiment is, has used the lattice bucket in the process that checks many objects.Describe specific operation process according to the checkout equipment of present embodiment in detail below in conjunction with accompanying drawing 20～25.

Figure 20 shows the side view according to the lattice bucket of present embodiment, and Figure 21 shows the vertical view of lattice bucket, and Figure 22 shows the backplan of lattice bucket.

As shown in figure 20, lattice bucket 70 comprises bottom and the sidewall that is coupled with the bottom.Lower surface in the bottom is provided with the projection of a plurality of tapers or other shapes.These three tapered protrusion can be inserted in the pilot hole corresponding on the load carrier 40, thereby in the load carrier rotary course, lattice bucket 70 prevents from producing relative motion with load carrier 40 rotations between the two.

In addition, as shown in figure 20, be provided with flange in one week of top of sidewall, handled easily person grasps and carrying.Sidewall is columned or taper, and can be by having the elastic side material, and for example tygon (PE) or aluminium are made.

Figure 21 is the vertical view of three kinds of lattice buckets.As shown in the figure, in the space that is formed by bottom and sidewall, be provided with one or more lattice parts, this space is divided into a plurality of spaces as required, be respectively applied to place liquid article.Like this, in the time will detecting many liquid articles simultaneously, these many liquid articles are placed on respectively in the space of being divided by the lattice parts, these liquid articles are detected simultaneously.In this case, can mark be set at the outside surface of sidewall, be convenient to when detecting inspection instrument in the location of article.For example, in detecting four article, there is one bottle when suspicious, can be according to the relative position of these part article with respect to the mark that arranges on the sidewall, coming to user report be which part article is suspicious.

For example, shown in the left hand view of Figure 21, be provided with the mark that the cross section is the circle of preliminary dimension at the upside of lattice parts, perhaps other little of the Length Ratio of certain lattice parts is thus as the used mark of location liquid article.

Figure 22 is the backplan of lattice bucket.Lower surface in the bottom is evenly distributed with three projections.It also can be inhomogeneous that but these three projections distribute.

Figure 23 shows the process that how automatically to detect lattice bucket and mark in checking process.As mentioned above, the lattice cylinder has specific structure, and the method for stencil matching commonly used detects in can processing with image.Take with the first bucket of cross lattice as example, step S810 can model one width of cloth with the template image of cross, and the center of this template placed CT picture centre to be identified, obtain matching value.

Then at step S811, whether judge this matching value greater than predetermined threshold value, if the result negate, then after the rotary template image, until the matching degree maximum of template image and CT image.There is the lattice cylinder if matching degree greater than certain predefined threshold value, is then thought among the CT figure, otherwise thinks and do not have the lattice cylinder among the CT figure.

If there is the lattice cylinder among the CT figure, can further come the detection and location mark according to specifically labelled characteristics at step S812.Still take with the first cylinder of cross lattice as example, its telltale mark is positioned at the top of a frame bar, makes this frame bar short than other three frame bars.After using template matching method to confirm to have the lattice cylinder among the CT figure, the cross curve when matching degree is maximum in the template image just in time overlaps with frame bar; By the length of four frame bars relatively, extract wherein the longest one, can obtain telltale mark.

After the multi-Slice CT imaging, at first every one deck CT image is carried out the detection of lattice cylinder and telltale mark detection.If all do not detect the lattice cylinder in each layer CT image, think that then the operator does not use the lattice cylinder; If detecting the lattice cylinder in one deck CT image at least, think that then the operator has used the lattice cylinder; If differ in the telltale mark position that each layer detects, the signal intensity maximum final telltale mark of conduct wherein.Describe that a method of telltale mark signal intensity is among certain one deck CT: the maximal value with four cut-off rule length of this layer deducts mean value, and its difference is larger, and the telltale mark signal is stronger.

Figure 24 A-24D shows the schematic diagram of rotary barrel in testing process.The telltale mark that only needs lattice to be detected cylinder is adjusted to the precalculated position, each lattice can be adjusted to assigned address.Take the first cross lattice cylinder as example, set up polar coordinate system take the CT picture centre as coordinate origin, the position of each lattice is determined by specifically labelled angle coordinate is unique.Supposing the system final corresponding polar angle of telltale mark of determining in various CT images is γ, and the predefined adjustment aim of system is θ, so only need each layer CT image and load carrier anglec of rotation θ-γ can be finished adjustment, be illustrated in fig. 24 shown below.

Shown in Figure 24 A and 24B, with angle of lattice bucket rotation, to reach the position that requires in advance.Equally, every layer of resulting image of CT imaging is rotated, makes its angle with postrotational lattice bucket consistent.

Figure 25 shows the process flow diagram according to the checking process of present embodiment.Because the step S710 with above-mentioned the 3rd embodiment is identical to step S721 from step S910 to step S921, step S922 is only described to step S926. here

At step S922, analyze the CT image, in judging, step S923 whether detects cylinder with lattice.If do not detect cylinder, then this checks and finishes.

Detect bucket if used, then at the telltale mark of step S924 recognition detection cylinder, determine the position of each lattice.Then at step S925 load carrier angle and each layer CT image angle are carried out second time and adjust, the position of each lattice in will detecting on the load carrier tin, and the position of each lattice on each layer of liquid CT image are all adjusted on the preposition.

At step S926, system lists the check result that drops on each liquid regions in each lattice part in every layer of CT image, is aggregated into the inspection conclusion of each lattice and is prompted to the user.A kind of method of summary according to present embodiment is: for certain lattice, only when dropping in all CT images that all liq zone all is judged to safe liquid in this lattice, the inspection conclusion of these lattice is " safety "; Otherwise the inspection conclusion of these lattice is " suspicious ".

[the 4th embodiment]

The first to the 3rd above embodiment has been described inspection method of the present invention and has been used for judging whether suspicious object of tested liquid article, but can judge directly also whether tested liquid article has hidden drugs.

The physical attribute of liquid (such as density and equivalent atom ordinal number) will change after hiding poison.Such as, the density of pure water is 1.00g/cm ³, atomic number is 7.5.

When being dissolved with the 50g cocaine in the 1000g water, its density becomes 1.01g/cm ³, atomic number is 7.6.

The method of substance for calculation (comprising potpourri) equivalent atom ordinal number is as follows:

Suppose that certain material contains N kind element altogether, various Atom of Elements are respectively Z _i, atom number number percent is α _i, i=1 wherein, 2 ..., N, and

The equivalent atom ordinal number of this material is so:

$Z_{\mathrm{eff}}={[\stackrel{N}{\underset{i=1}{\mathrm{\&Sigma;}}}{\mathrm{\&alpha;}}_i{Z_i}^{4.5}/\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{\mathrm{\&alpha;}}_i{Z}_i]}^{\frac{1}{3.5}}$

Like this, with water (H ₂O) be example, the computation process of its equivalent atom ordinal number is as shown in table 1 below:

The variation of density, atomic number behind the poison of liquid Tibetan (dissolving cocainehydrochloride as example in water) is as shown in table 2 below:

In addition, Figure 26 A is the change curve of explanation liquid density after having hidden drugs.Figure 26 B is the change curve of explanation liquid atomic number after having hidden drugs.Figure 26 C is the change curve of explanation liquid characteristic density after having hidden drugs.

The below's contrast accompanying drawing 27 describes the inspection method of embodiment of the present invention in detail.

At step S1010, the operator is placed on tested liquid article on the load carrier 40, and the identification information that obtains this liquid article according to passenger's customs declaration or the label on the liquid article, for example one bottle of water.

Then, at step S1011, the operator searches for from database according to this identification information and obtains its reference density and referencing atom ordinal number, and for example density is 1.00 (characteristic density 1.11) g/cm ³, the referencing atom ordinal number is 7.51.Next, the operator presses start button and begins to carry out DR scanning, to generate the DR image.

After obtaining the DR image, at step S1013A, the DR image is analyzed, automatically determine the scanning position of CT imaging, perhaps at step S1013B, specify the position that will carry out CT scan by the input media 65 of operator's operation such as mouse.Like this and since only in the liquid towards article representational position carry out CT scan, thereby accelerated inspection speed, do not check on the quality and can not reduce.

After the position of having determined CT scan, carry out the CT scan process at step S1014, namely carry out CT scan for above-mentioned definite scanning position liquid towards article, obtain the CT scan data, and calculate CT image reconstruction according to rebuilding.Each pixel of this CT image has represented density and the atomic number of appropriate section in the liquid article.

Then, at step S1015, computing machine is analyzed the CT image by execution analyzer, obtains density and the atomic number of measurement, and for example recording its density is 1.02 (characteristic density 1.13) g/cm ³, atomic number 7.71.And then, at step S1016, by can be calculated actual density and reference value differs 0.02g/cm ³, atomic number differs 0.20.Be set as density difference 0.01g/cm if hide malicious discrimination threshold ³, atomic number differs from 0.10, and the density of measuring so and atomic number have dropped within the predetermined scope.At step S1017, if difference shows then that greater than predetermined threshold value this liquid article is suspicious, send warning to the operator, perhaps print check result.

Differentiate required reference density and atomic number, can measure in advance a sample of this class I liquid I, and be saved in the database.Differentiate required difference threshold value, can manually be set as a suitable value.If wish to detect the drugs of trace, then this threshold value can be made as smaller value; Its risk is, even do not hide the checking matter of poison, also may record a larger deviate because of the reason of system noise, thereby cause wrong report.Otherwise, if wish to reduce as much as possible for not hiding the wrong report of venom body, then threshold value should be made as higher value; Its risk is, if tested liquid keeps a small amount of drugs, then its density variation is not enough to reach discrimination threshold, will cause failing to report.

Although abovely be illustrated as an example of single inspection object example, as those of ordinary skill in the art institute clearly, the method for the 4th embodiment can be applied to many bottles of detections equally as the second embodiment and the 3rd embodiment.

[modification 1]

Although above with carry out first the DR imaging then carry out CT be imaged as the example embodiments of the invention are illustrated, also can directly carry out the spiral CT imaging and come the liquid towards article to check.

The liquid towards article carry out spiral CT and check that resulting is one group of spiral CT image, by relatively and analyze pixel in this group CT image, just can determine the position of liquid in the liquid article, and whether layering of liquid, then utilize with as described above similarly method obtain the physical property values of the liquid of each layer position, for example density and atomic number.For example when as shown in figure 28 liquid article is carried out the spiral CT imaging, if scan take 2cm as screw pitch, will obtain one group of CT image shown in Figure 29 A-29M.Like this, by analyzing the pixel value in each spiral CT image, the position that just can learn liquid in the liquid article.The spiral CT imaging here can be adopted coarse pitch CT imaging or conventional pitch CT imaging.

In addition, although toply be illustrated as an example of density and atomic number example, the present invention can only carry out with one of density or atomic number equally, perhaps carries out with other more physical attributes.

[modification 2]

Although above to carry out first the DR imaging, then carry out dual intensity CT imaging and obtain density and the atomic number of liquid, but the DR imaging here is not necessary, because can specify in advance preposition to carry out dual intensity CT imaging for different liquid articles, obtain density and the atomic number of liquid.

Top description only is used for realizing embodiments of the present invention; it should be appreciated by those skilled in the art; the any modification or partial replacement that is not departing from the scope of the present invention; all should belong to claim of the present invention and come restricted portion; therefore, protection scope of the present invention should be as the criterion with the protection domain of claims.

Claims (31)

1. method that checks with dual intensity CT liquid towards article comprises step:

Carry out the transmission image that DR scanning obtains tested liquid article for liquid article;

Analyze the pixel value of described transmission image, to determine the whether layering of described transmission image;

The dual intensity CT scan is carried out to tested liquid article at least one position in determined each layer, obtains dual intensity CT data for projection, and wherein, described dual intensity CT scan adopts the mode of plane fault CT scan;

Carry out CT according to described data for projection and rebuild, obtain representing the CT image of the physical property values of tested liquid article;

Extract the physical property values of tested liquid article according to described CT image; And

Reference physical property values based on described physical property values and this liquid article judges whether suspicious described tested liquid article is.

2. the method for claim 1, wherein said physical property values comprises density and the atomic number of tested liquid article.

3. the method for claim 1 is appointed as the position that will carry out the dual intensity CT scan with the middle row in each layer.

4. method as claimed in claim 3, obtain transmission image after, by image processing techniques automatically determine each layer in the transmission image in the middle of row, as the CT scan position.

5. method as claimed in claim 4, wherein carry out the step that DR scanning obtains the transmission image of tested liquid article for liquid article and comprise:

Send high-energy ray and low energy ray from radiographic source, penetrate tested liquid article, form high energy transmission image and low energy transmission image;

Merge high energy transmission image and low energy transmission image, form described transmission image.

6. method as claimed in claim 4, wherein carry out the step that DR scanning obtains the transmission image of tested liquid article for liquid article and comprise:

Send high-energy ray and low energy ray from radiographic source, penetrate tested liquid article, form high energy transmission image and low energy transmission image;

Select one of high energy transmission image and low energy transmission image, as described transmission image.

7. the method for claim 1 is wherein carried out CT according to described data for projection and is rebuild, and obtains representing that the step of CT image of the physical property values of tested liquid article comprises:

According to high low energy data for projection, generate the data for projection about two kinds of sill coefficients;

Data for projection according to described two kinds of sill coefficients is rebuild, and obtains representing the CT image of the corresponding two kinds of sill coefficients of tested liquid article; And

According to described expression sill coefficient CT image, generate the CT image of the tested liquid article physical property values of described expression.

8. the method for claim 1, the step of wherein extracting tested liquid article physical property values according to described CT image comprises:

From described CT image, extract the pixel corresponding with the liquid part;

To pixel bulk density average and the atomic number average of liquid part, as density and the atomic number of described tested liquid article.

9. the method for claim 1, wherein judge based on the reference physical property values of described physical property values and this liquid article whether suspicious step comprises described tested liquid article:

Difference between bulk density and atomic number and reference density and the atomic number;

In the situation of described difference greater than predetermined threshold value, think and hidden drugs in the described tested liquid article.

10. the method for claim 1 wherein after carrying out the dual intensity CT scan for each position, is rotated the CT image that is examined liquid article, makes itself and the formed image alignment of the dual intensity CT scan first time.

11. method as claimed in claim 10 wherein after carrying out the dual intensity CT scan for each row, is rotated tested liquid article, makes it identical with the position before the scanning.

12. the method for claim 1, wherein said liquid article are placed in the bucket that has been divided into a plurality of spaces.

13. method as claimed in claim 12 comprises step:

Utilize predetermined template automatically to detect the existence of bucket;

In the situation that there is bucket, detect the specific markers in the CT image;

Based on described specific markers, bucket is rotated to preposition.

14. such as claim 11 or 13 described methods, also comprise step:

With the judgment result displays of tested liquid article on display screen.

15. such as claim 11 or 13 described methods, also comprise step:

The judged result of each tested liquid article is printed.

16. such as claim 11 or 13 described methods, also comprise step:

CT image color with each tested liquid article.

17. an equipment that checks with dual intensity CT liquid towards article comprises:

Radiographic source is used for sending ray;

Survey and harvester, be used for surveying and gathering the ray signal that penetrates at least one tested liquid article;

Controller is controlled described radiographic source and detection and harvester tested liquid article is carried out DR scanning, obtains the transmission image of tested liquid article;

Analyze the pixel value of described transmission image, to determine the whether device of layering of described transmission image, wherein said controller is controlled described radiographic source and detection and harvester at least one position in determined each layer tested liquid article is carried out the dual intensity CT scan, obtain dual intensity CT data for projection, wherein, described dual intensity CT scan adopts the mode of plane fault CT scan;

Described equipment also comprises:

Rebuild the device of the CT image of the physical property values that represents tested liquid article from data for projection; And

Judge whether suspicious device of described tested liquid article based on the reference physical property values of described physical property values and this liquid article.

18. equipment as claimed in claim 17, wherein said physical property values comprise density and the atomic number of tested liquid article at least.

19. equipment as claimed in claim 17 wherein sends high-energy ray and low energy ray from radiographic source, penetrates tested object, forms high energy transmission image and low energy transmission image, described equipment also comprises:

Merge the device that high energy transmission image and low energy transmission image form described transmission image.

20. equipment as claimed in claim 17 wherein sends high-energy ray and low energy ray from radiographic source, penetrates tested object, forms high energy transmission image and low energy transmission image, described equipment also comprises:

Select one of high energy transmission image and low energy transmission image, as the device of described transmission image.

21. equipment as claimed in claim 17 wherein, is appointed as the row that will carry out the dual intensity CT scan with the middle row in each layer.

22. equipment as claimed in claim 17 wherein comprises from the device of CT image that data for projection is rebuild the physical property values of the tested liquid article of expression:

The density image that fusion is identified by the density of tested liquid article and the atomic number image that identified by the atomic number of tested liquid article are as the device of described CT image;

From described CT image, extract the device of the pixel corresponding with the liquid part;

To the pixel bulk density average of liquid part and atomic number average as the density of described tested liquid article and the device of atomic number.

23. equipment as claimed in claim 17 wherein judges based on the reference physical property values of described physical property values and this liquid article whether suspicious device comprises described tested liquid article:

The device of the difference between bulk density and atomic number and reference density and the atomic number; In the situation of described difference greater than predetermined threshold value, think and hidden drugs in the described tested liquid article.

24. equipment as claimed in claim 17 also comprises: after carrying out the dual intensity CT scan for every row, rotation is examined the CT image of liquid article, makes itself and the device of the formed image alignment of dual intensity CT scan for the first time.

25. equipment as claimed in claim 17 also is included in for each row and carries out rotating tested liquid article after the dual intensity CT scan, makes the identical device in position before itself and the scanning.

26. equipment as claimed in claim 17 also comprises bucket, has been divided into a plurality of spaces, is respectively applied to place described liquid article.

27. equipment as claimed in claim 26 comprises:

Utilize predetermined template automatically to detect the device of the existence of bucket;

In the situation that there is bucket, detect the device of the specific markers in the CT image;

Based on described specific markers, bucket is rotated to the device of preposition.

28. such as claim 25 or 27 described equipment, also comprise:

Display device shows the judged result of tested liquid article.

29. such as claim 25 or 27 described equipment, also comprise:

The device that the judged result of each tested liquid article is printed.

30. such as claim 25 or 27 described equipment, also comprise:

Device with the CT image color of each tested liquid article.

31. equipment as claimed in claim 17 also comprises the load carrier that carries described tested liquid article, described load carrier carries on the surface of described tested liquid article and is divided into the discernible a plurality of zones of operating personnel.

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