CN102095666B - Method and equipment for checking liquid object - Google Patents

Method and equipment for checking liquid object Download PDF

Info

Publication number
CN102095666B
CN102095666B CN 201010621640 CN201010621640A CN102095666B CN 102095666 B CN102095666 B CN 102095666B CN 201010621640 CN201010621640 CN 201010621640 CN 201010621640 A CN201010621640 A CN 201010621640A CN 102095666 B CN102095666 B CN 102095666B
Authority
CN
China
Prior art keywords
image
liquid article
seized
transmission image
article
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN 201010621640
Other languages
Chinese (zh)
Other versions
CN102095666A (en
Inventor
张丽
陈志强
王学武
胡海峰
吴宏新
李元景
刘以农
赵自然
邢宇翔
唐虎
易裕民
张金宇
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tsinghua University
Nuctech Co Ltd
Original Assignee
Tsinghua University
Nuctech Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tsinghua University, Nuctech Co Ltd filed Critical Tsinghua University
Priority to CN 201010621640 priority Critical patent/CN102095666B/en
Publication of CN102095666A publication Critical patent/CN102095666A/en
Application granted granted Critical
Publication of CN102095666B publication Critical patent/CN102095666B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Analysing Materials By The Use Of Radiation (AREA)

Abstract

The invention discloses a method and equipment for checking a liquid object by dual-energy computed tomography (CT). The method comprises the following steps of: performing data register (DR) scanning on the liquid object to acquire the transmission image of the checked liquid object; analyzing the pixel value of the transmission image to judge whether the transmission image is layered or not; performing dual-energy CT scanning on the checked liquid object at the at least one position of each determined layer to acquire dual-energy CT projection data; performing CT reconstruction according tothe projection data to acquire a CT image which indicates the physical attribute value of the checked liquid object; exacting the physical attribute value of the checked liquid object according to the CT image; and judging whether the checked liquid object is an dangerous object or not based on the physical attribute value. By the method, the liquid product can be quickly checked.

Description

Liquid article examination method and equipment
The application submitted to the dividing an application of No. 200710180652.8 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 forms images the liquid towards article fast and safely to check through the liquid towards article.
Background technology
After 911 incidents of the U.S. took place, 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 effective and efficient manner and means and carry out the inspection fast and safely of liquid article in the luggage and articles.
Current, have following four types method 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 smell identification, ion scan is surveyed and species analysis.Smell is identified in usually can't be realized inspection because liquid article is packed in the practical application.Ion scan is surveyed with hypersensitivity and is celebrated, and is high but its shortcoming is rate of false alarm, usually receives the influence of background environment.Species analysis has the high and high characteristics of accuracy of precision, but this method needs the regular hour that sample is analyzed, and can not satisfy the demand of on-the-spot quick check.
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 receives the adverse effect of mental package and thicker material packing easily.Therefore, under the actual conditions of wrappage complicacy, electromagnetic method has certain limitation.
3) phenomenon of " neutron activation " can appear in the use of neutron inspection method, and promptly the liquid article that is examined through the neutron inspection has the radiation residual phenomena.And,,, thereby be not suitable in the safety check system of civil aviaton, using so its radiation shield is more complicated, occupation area of equipment is big because the penetration capacity of neutron is stronger.
4) current, mostly the safety inspection device of aviation field is x-ray apparatus, and in these devices, adopting maximum technology at present is X ray two-dimensional imaging technology and three-D CT scanning imaging technique.These technology are mainly used in carries out safety inspection to luggage and articles, can not carry out safety inspection to the liquid article in the luggage and articles specially.
X ray two-dimensional imaging technology is the two-dimensional signal projected image that the three-dimensional information of inspected object is obtained object in X-ray beam direction upper integral.These images adopt the form of expression of gray scale or pseudo-colours to show the structure of interior of articles, give the equipment operator to show intuitively.Therefore but X ray two-dimensional imaging technology has lacked the information of a dimension of inspected object after all, checks the especially severe that influences that receives the profile that is examined liquid article and size with these technology liquid towards article.
The three-D CT scanning imaging technique is the promotion and application of CT technology.The CT technology is applied to medical science the earliest, is the instrument that auxiliary doctor diagnoses.It is to realize through the projection that each tomography to checked property carries out multi-angle.Through the reconstruction of computing machine to the multi-angle projection data of above-mentioned each tomography, calculate the reconstructed image of each tomography, show different attenuation coefficient information in the reconstructed image with different gray scales, thereby show the inner structure of checked property.Development along with the CT technology; The industry CT that nondestructive examination occurred being used for and the luggage CT that is used for safety inspection etc.; These CT expand technology, and to remain with the faultage image that obtains to show internal structure of body be purpose; Depend on manual work structure is analyzed, whether belong to dangerous goods, be not suitable for automatic, quick check to judge checking matter.In addition, above-mentioned CT type safety inspection equipment because of the checked property scope that it covered is wide, and causes cost high, and equipment is heavy, applies difficulty.
In sum; Carry out quick check 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 show the image of article inner structure, can not abundant foundation be provided for automatic, the safety inspection of liquid article.
Summary of the invention
In order to overcome the deficiency that exists in the above-mentioned prior art; The purpose of this invention is to provide a kind of method and apparatus that carries out safety inspection with ray liquid towards article; It can carry out quick check to it under the situation of not destroying the liquid article packing, obtain being examined the quantitative information of liquid article.
In one aspect of the invention, proposed a kind of method of checking with dual intensity CT liquid towards article, comprised step: carried out the transmission image that DR scanning obtains seized liquid article to liquid article; Analyze the pixel value of said transmission image, to confirm the whether layering of said transmission image; The dual intensity CT scan is carried out to seized liquid article at least one position in determined each layer, obtains dual intensity CT data for projection, and wherein, said dual intensity CT scan adopts the mode of plane fault CT scan; Carry out CT according to said data for projection and rebuild, obtain representing the CT image of the physical property values of seized liquid article; Extract the physical property values of seized liquid article according to said CT image; And judge based on said physical property values whether said seized liquid article is dangerous material.
According to embodiments of the invention, said physical property values comprises the density and the atomic number of seized liquid article.
According to embodiments of the invention, the middle line in each layer is appointed as the position that to carry out the dual intensity CT scan.
According to embodiments of the invention, obtain transmission image after, confirm the middle line of each layer in the transmission image automatically through image processing techniques, as the CT scan position.
According to embodiments of the invention, the step that forms transmission image comprises: send high-energy ray and low energy ray from radiographic source, penetrate seized object, form high energy transmission image and low energy transmission image; Merge high energy transmission image and low energy transmission image, form said transmission image.
According to embodiments of the invention, the step that forms transmission image comprises: send high-energy ray and low energy ray from radiographic source, penetrate seized object, form high energy transmission image and low energy transmission image; Select one of high energy transmission image and low energy transmission image, as said transmission image.
According to embodiments of the invention, the step of rebuilding the CT image of the physical property values of representing seized liquid article from the dual intensity data for projection 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 said two kinds of sill coefficients is rebuild, and obtains representing the CT image of the pairing two kinds of sill coefficients of seized liquid; And, generate the CT image of the seized liquid article physical property values of said expression according to said expression sill coefficient CT image.
According to embodiments of the invention, according to the CT image of the physical property values of representing seized liquid article, the step that obtains seized liquid article physical property values comprises: from said CT image, extract and the corresponding pixel of liquid part; To the pixel bulk density average and the atomic number average of liquid part, as the density and the atomic number of said seized liquid article.
According to embodiments of the invention, judge that based on said physical property values whether said seized liquid article is that the step of dangerous material comprises: judge whether the determined point of density and atomic number drops in the presumptive area in density-atomic number two-dimensional coordinate space; Drop under the situation in the said presumptive area at said point, think that said seized liquid article is dangerous material.
According to embodiments of the invention, after carrying out the dual intensity CT scan to 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, rotate seized liquid article to each row, make it identical with the position before the scanning.
According to embodiments of the invention, said liquid article is placed in the bucket that has been divided into a plurality of spaces.
According to embodiments of the invention, said method comprises step: utilize predetermined template to come to detect automatically the existence of bucket; Under the situation that has bucket, detect the specific markers in the CT image; Based on said specific markers, bucket is rotated to preposition.
According to embodiments of the invention, said method also comprises step: with the judgment result displays of seized liquid article on display screen.
According to embodiments of the invention, said method also comprises step: the judged result of each seized liquid article is printed.
According to embodiments of the invention, said method also comprises step: with the CT image colorization of each seized liquid article.
In another aspect of this invention, a kind of equipment of checking with dual intensity CT liquid towards article is provided, comprising: radiographic source is used to send ray; Survey and harvester, be used to survey and gather the ray signal that penetrates at least one seized liquid article; Controller is controlled said radiographic source and detection and harvester seized liquid article is carried out DR scanning, obtains the transmission image of seized liquid article; Analyze the pixel value of said transmission image; To confirm the whether device of layering of said transmission image; Wherein said controller is controlled said radiographic source and detection and harvester at least one position in determined each layer seized liquid article is carried out the dual intensity CT scan; Obtain dual intensity CT data for projection, wherein, said dual intensity CT scan adopts the mode of plane fault CT scan; Said equipment also comprises: the device of rebuilding the CT image of at least a physical property values of representing seized liquid article from data for projection; And judge based on the position of said physical property values in the space of respective dimensions whether said seized liquid article is the device of dangerous material.
According to embodiments of the invention, said physical property values comprises the density and the atomic number of seized liquid article at least.
According to embodiments of the invention; Send high-energy ray and low energy ray from radiographic source; Penetrate seized object, form high energy transmission image and low energy transmission image, said equipment also comprises: merge the device that high energy transmission image and low energy transmission image form said transmission image.
According to embodiments of the invention; Send high-energy ray and low energy ray from radiographic source, penetrate seized object, form high energy transmission image and low energy transmission image; Said equipment also comprises: select one of high energy transmission image and low energy transmission image, as the device of said transmission image.
According to embodiments of the invention, the middle line 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 seized liquid article of expression from data for projection comprises: merge by the density image that density identified of seized liquid article with by the atomic number image that atomic number identified of the seized liquid article device as said CT image; From said CT image, extract and the corresponding pixel of liquid part; To the pixel bulk density average of liquid part and atomic number average as the density of said seized liquid article and the device of atomic number.
According to embodiments of the invention; Judge that based on said physical property values whether said seized liquid article is that the device of dangerous material comprises: judge whether the determined point of density and atomic number drops on the device in the presumptive area in density-atomic number two-dimensional coordinate space; Wherein, Drop under the situation in the presumptive area at said point, think that said seized liquid article is dangerous material.
According to embodiments of the invention, said equipment also comprises: to after every row carries out the dual intensity CT scan, 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, said equipment also is included in to each row and carries out rotating seized liquid article after the dual intensity CT scan, makes itself and the scanning identical device in position before.
According to embodiments of the invention, said equipment also comprises bucket, has been divided into a plurality of spaces, is respectively applied for to place said liquid article.
According to embodiments of the invention, said equipment comprises: utilize predetermined template to come to detect automatically the device of the existence of bucket; Under the situation that has bucket, detect the device of the specific markers in the CT image; Based on said specific markers, bucket is rotated to the device of preposition.
According to embodiments of the invention, said equipment also comprises: display device shows the judged result of seized liquid article.
According to embodiments of the invention, said equipment also comprises: the device that the judged result of each seized liquid article is printed.
According to embodiments of the invention, said equipment also comprises: with the device of the CT image colorization of each seized liquid article.
According to embodiments of the invention, said equipment also comprises the load carrier that carries said seized liquid article, and said load carrier carries on the surface of said seized liquid article and is divided into the discernible a plurality of zones of operating personnel.
Utilize method and apparatus of the present invention,, when having improved detection speed, do not reduce the detection accuracy rate, and can also judge through transmission image whether liquid article exists interlayer owing to adopt transmission image to carry out the dual intensity CT scan as guiding.
In addition, whether drop in the presumptive area of two-dimensional space, can judge whether seized liquid article is explosive through judging density and the atomic number measured.
In addition, the operator can carry out the dual intensity CT scan in any appointed positions, has made things convenient for the carrying out of check operation.
In addition, under many situation about detecting simultaneously, adopt the lattice bucket, can confirm easily whether the seized liquid article of that part is explosive.
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 as shown in Figure 1 60;
Fig. 3 shows the structured flowchart according to the controller of first embodiment of the invention;
Fig. 4 A and 4B show the synoptic diagram according to the method for inspection liquid article of the present invention;
Fig. 5 is used to explain that DR forms images and the synoptic diagram of the relation of 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 is gathered;
Figure 11 shows the DR image is handled to confirm 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 A and Figure 15 B show the synoptic diagram of the CT image of rebuilding under the situation according to many liquid articles of detection of second embodiment of the invention;
Figure 16 A shows after the CT imaging is accomplished to 16K, how CT reconstructed image and/or load carrier is rotated itself and the CT scan corresponding to process of relative position of object before that makes;
Figure 17 shows the process flow diagram of under the situation of many seized objects, checking;
Figure 18 shows the vertical view according to the load carrier of second embodiment of the invention;
Figure 19 shows the side view according to the lattice bucket of this embodiment;
Figure 20 shows the vertical view of lattice bucket;
Figure 21 shows the backplan of lattice bucket;
Figure 22 shows the process that in checking process, how to detect lattice bucket and mark automatically;
Figure 23 A shows the synoptic diagram of rotary barrel in testing process to 23D;
Figure 24 shows the process flow diagram according to the checking process of the 3rd embodiment;
Figure 25 is the synoptic diagram that explanation liquid towards article carry out CT scan;
Figure 26 A is that explanation liquid towards article carry out the resulting image of CT scan to 26M.
Embodiment
Below, specify preferred implementation of the present invention with reference to accompanying drawing.In the accompanying drawings, though be shown in the different drawings, identical Reference numeral is used to represent identical or similar assembly.For clear and simple and clear, the known function and the detailed description of structure that are included in here will be omitted, otherwise they will make theme of the present invention unclear.
[first embodiment]
Fig. 1 is the structural representation according to the checkout facility of embodiment of the present invention.
As shown in Figure 1, comprise according to the checkout facility of this embodiment: send the radiographic source 10 of inspection, such as X-ray machine with dual-energy x-ray; Load carrier 40, it carries seized liquid article and rotates around axle Z, and can go up and down, and makes seized liquid article get into surveyed area, thereby can see through seized 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 to survey the dual intensity ray of the seized liquid article of transmission; Obtain simulating signal, and analog signal conversion is become digital signal, thereby the dispensing liquid article are to the scan-data of sigmatron and low energy X ray; Controller 50, it is used to control the various piece synchronous working of total system; And computer data processor 60, it is used for handling the data of being 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 seized liquid article; Detection and harvester 30 place the opposite side of load carrier 40, comprise detector and data acquisition unit, are used to obtain seized 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 and to be connected with computer data processor 60 with the data output cable of harvester 30, according to trigger command with the data storage of collection in 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.Seized liquid article is placed in the seized object passage.
Fig. 2 shows the structured flowchart of computer data processor as shown in Figure 1 60.As shown in Figure 2, the data that data acquisition unit is gathered are stored in the storer 61 through interface unit 68 and bus 64.Store the 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 the computer program that is used to carry out data processing in the storer 61.Internal bus 64 connects above-mentioned storer 61, ROM (read-only memory) 62, RAS 63, input media 65, processor 66, display device 67 and interface unit 68.
After the operational order of user through 65 inputs of the input media 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 exports result with the form 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 instruction, control radiographic source 10, load carrier 40 and detection and harvester 30 from computing machine 60; Trigger pip generation unit 52 is used under the control of control module producing the trigger command of the action that is used for triggering radiographic source 10, detection and harvester 30 and load carrier 40; First drive motor 55, it drives load carrier 40 at the trigger command that under the control of control module 51, produces according to trigger pip generation unit 52 and rises or descend; 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; Second drive motor 56, the trigger command that it produces under the control of control module 51 according to trigger pip generation unit 52 drive load carrier 40 rotations; 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 all is a photoelectric code disk with angle information acquiring unit 54, and it possesses jamproof advantage.
According to embodiments of the invention, through measuring density of liquid and atomic number in the liquid article, and judge whether density and the atomic number measured drop in the predefined hazardous location, inspection method of the present invention can be used for detecting dangerous material.For density and atomic number, safe liquid (such as beverage, skin care item, cosmetics etc.) and dangerous liquid (such as flammable liquid, liquid explosive, strongly corrosion liquid etc.) have very big-difference.Such as, as the water of safe liquid, density approximately is 1 (characteristic density 1.11), atomic number approximately is 7.51.And as the alcohol of dangerous liquid, its density approximately is 0.79 (characteristic density 0.89), and atomic number approximately is 6.47.Utilize the method for pattern-recognition, can safe liquid and dangerous liquid be separated according to density and atomic number.
Fig. 4 A and 4B show the synoptic diagram according to the method for inspection liquid article of the present invention.In the two-dimensional space that density and atomic number are constituted, mark one or more zones, when the density of checking matter and atomic number drop in these zones, then be judged to safe liquid, otherwise be judged to dangerous liquid.And definite method in safe liquid zone is, surveys a large amount of safe liquid and dangerous liquid, gets safe liquid and concentrates and the more sparse zone of dangerous liquid, as the safe liquid zone.Shown in Fig. 4 A, through various density of liquid of actual measurement and atomic number, the zone at zone that definite safe liquid is fallen in density and atomic number two-dimensional space and dangerous liquid place.Then, shown in Fig. 4 B, the zone at safe liquid place is shunk so that improve the sensitivity that detects.Like this, after having obtained the density and atomic number of liquid article, just can judge whether it is dangerous material according to its position on two-dimensional space through above-mentioned method.
Fig. 5 is used to explain that DR forms images and the synoptic diagram of the relation of CT imaging.According to the embodiment of the present invention, at first the liquid towards article carry out the DR imaging, so that judge the liquid part in the liquid article, only carry out the CT imaging to certain position in the liquid part then, so that improve the speed of inspection.
Fig. 6 and Fig. 7 show the example of DR imaging respectively.As shown in Figure 6, after certain liquid article being carried out DR imaging, pixel value analysis is judged the position of liquid in the liquid article through what be 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, carry out pixel analysis through the DR image that DR imaging back is obtained and judge the interfacial position between the liquid.Then, carry out the CT imaging to 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 carry out safety inspection to the liquid article that the passenger carries.At first at step S111, the operator is placed on seized liquid article on the load carrier 40.
Next, at step S112, the operator presses start button and begins to carry out DR scanning, to generate the DR image, shown in Fig. 6 and 7.
As stated, the purpose of carrying out DR scanning is: the one, obtain the fluoroscopy images of seized liquid article, and make the operator can see the inner structure of seized liquid clearly; The 2nd, software can be discerned liquid position automatically according to the DR image, guides next step CT imaging; The 3rd, the user can need carry out the position of CT imaging and inspection in the appointment of DR image, guides next step CT imaging.The back will be described the detailed process of DR imaging in detail.
Mandatory declaration be that DR scanning is not necessary.In order to accelerate inspection speed, can not scan and guide CT scan, but CT scan is carried out in directly predetermined some positions through DR.Such as, through investigation, can know at the distance bottle end 5 centimetres carry out CT scan the time, can be checked through the liquid position of most of liquid commodity, then can use be the height of bottle end 5 centimetres away from as a predetermined scanning height.In addition, the operator can be provided with suitable height by rule of thumb through range estimation checking matter size, is 3cm such as the laughable scanning height of jar shape is set, and thicker scanning height vinous is 10cm at the bottom of being provided with bottle.
After obtaining the DR image, at step S113A, the DR image is analyzed, confirm the scanning position of CT imaging automatically, perhaps at step S113B, 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 confirmed CT scan, carry out the CT scan process at step S114, just carry out CT scan to above-mentioned definite scanning position liquid towards article, obtain the CT scan data, and rebuild the CT image according to rebuilding to calculate.Each pixel of this CT image has been represented the density and the atomic number of appropriate section in the liquid article.
Then, at step S115, computing machine is analyzed the CT image through execution analyzer, obtains the density and the atomic number of measurement.And then, at step S116, judge whether the density and the determined point of atomic number of actual measurement has dropped on by in the presumptive area in two coordinate spaces of density-atomic number.At step S117,, show that then this liquid article is that suspicious perhaps being likely sent warning to the operator by dangerous material, perhaps prints check result if the determined point of density and atomic number has dropped in the predetermined explosive area.
Specify the detail operations process of above-mentioned each step 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 is gathered.
As shown in Figure 9, in the DR imaging process,, send order to controller 50, to drive load carrier 40 along 20 vertical movements of object passage from computing machine 60 at step S210.Controller 50 is monitored the height of load carrier in real time through elevation information acquiring unit 53 in the process of load carrier vertical movement.
At step S211, controller 50 every giving at a distance from certain height (such as 1 millimeter) are surveyed and trigger pip of harvester 30 transmissions.After detection and harvester 30 receive this trigger pip, the output signal of each detector is once gathered, obtained 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 write down ray and has penetrated remaining intensity behind the object, comprises low energy ray intensity and high-energy ray intensity.
As stated, the scanning position of follow-up CT imaging is all confirmed on the DR image.No matter be to use automatic identification mode; Still the mode of artificial appointment all is at first on the DR image, to obtain a row number, and computing machine number converts this row into the load carrier height then; And after instruction control unit 50 drives load carriers 40 and move to assigned address, carry out the CT imaging again.
Can know that by DR imaging flow process each row of DR image is corresponding to a 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, and every the triggering once at a distance from the h millimeter gathered, 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 handled to confirm the process flow diagram of CT scan position.
In the DR image, at the bottom of seized liquid article generally is divided into bottle, several parts such as liquid part, bottleneck, bottle cap, can liquid part (having multilayer) be wherein extracted through image analysis technology, and confirm each layer CT scan position.
At step S310, the high low energy data of DR image are merged with 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 Processing.
At step S311, extract the seized liquid article (prospect) in the DR image of level and smooth back, 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: seized liquid article has blocked ray, so its corresponding DR pixel value lower (DR image recording be the residual intensity of ray).
At step S312, extract the horizontal edge pixel in the DR image of level and smooth back.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 certain greatly more than the threshold value, just think that this pixel belongs to the horizontal edge pixel.
At step S313, the horizontal edge that extracts in the DR image of level and smooth back is capable, and 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 each row of along continuous straight runs in the DR image, and the ratio of adding up its horizontal edge number of picture elements and foreground pixel number, if ratio arrives certain threshold value above (such as 50%) greatly, it is capable then this delegation to be classified as horizontal edge.
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 (difference according to density has multilayer), the bottle.Through 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 just, 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.Confirming of concrete threshold value can be confirmed through 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.Confirming of concrete threshold value can be confirmed through realizing the width that obtains various liquid package container bottlenecks.
At step S315, confirm the CT scan position of liquid regions (having a plurality of), accomplish the layering location of liquid.After getting rid of the on-liquid zone, remaining zone (having a plurality of) is classified as liquid regions.Get the central row of these zones on short transverse, as the CT scan position.
What more than describe is the process of confirming the CT scan position automatically.But under the situation of manual invisible scanning position, the operator is through the row of input media 65 direct appointment on the DR image that shows will carrying out CT scan, 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.
Shown in figure 12, after the position of having confirmed CT scan, carry out the CT imaging process; Just in performed CT scan position; Carry out the CT imaging, generate density and atomic number image, to carry out the measurement of fluid density and atomic number about a tomography of checking matter.As stated, owing to only CT scan is carried out in typical position, so can save the time of being open to the custom greatly.
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 monitored the load carrier angle through angle information acquiring unit 54 in real time in the process that load carrier rotatablely moves.
At step S411, when turning over 1 degree, controller 50 is given and is surveyed and trigger pip of harvester 40 transmissions.After detection and harvester 40 receive 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, and is shown in figure 13.Each pixel of CT data for projection has write down 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 and obtains density and the atomic number image on the tomography, i.e. CT image.Each pixel in the CT image has write down density and the atomic number of seized object at this pixel correspondence position.
The process of faultage image is rebuild in explanation from high low energy CT data for projection below.
● the CT mathematical principle
(x y) asks line integral along certain direction θ, just obtains the function p of one dimension with Two dimensional Distribution u θ(t), this function is called u (x is y) in the projection of θ angle.If can access the projection p of all directions θ(t), so can according to Radon conversion accurate Calculation obtain Two dimensional Distribution u (x, y).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 check system (＜200keV), the material line attenuation coefficient can use following analytical expression (1) to come approximate representation.
μ(E)＝a 1f p(E)+a 2f KN(E) (1)
a 1 = ρZ M Z n - - - ( 2 )
a 2 = ρZ M - - - ( 3 )
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 representes atomic number, and M representes mass number, and ρ representes density (g/cm 3), n is a constant.
Because the line attenuation coefficient of every kind of material can be by two coefficient a in the formula (1) 1And a 2Uniquely confirm, therefore can choose two kinds of sills,, represent other all materials with the linear combination of the line attenuation coefficient of sill such as carbon and aluminium, 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.
ρ * = ρ 2 Z M - - - ( 5 )
Suppose two basic materials, atomic number and characteristics of densities were and
Figure GDA00001844817200163
then according to the above formula (1) to (4) can be deduced from any of the atomic number and characteristics of the material density expressed as follows:
ρ * = b 1 ρ 1 * + b 2 ρ 2 * - - - ( 6 )
Z = ( b 1 ρ 1 * Z 1 n + b 2 ρ 2 * Z 2 n b 1 ρ 1 * + b 2 ρ 2 * ) 1 / n - - - ( 7 )
● the sill projection model
The power spectrum that the X-ray pipe 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,
∫ 0 E m S ( E ) dE = 1 - - - ( 8 )
The expression formula of the projection value on projection line is following integration type so:
p = - ln I I 0 = - ln ∫ 0 E m S ( E ) exp ( - ∫ l μ ( E , x , y ) dl ) dE - - - ( 9 )
In the formula (9), I 0With I represent respectively ray by before the object decay with decay after the detector readings value, E mThe ceiling capacity of expression ray, l representes the path that ray passes.
Formula (9) is measurement projection value p and Two dimensional Distribution μ (x, relation y) of real system.Can find out that because the X ray pleochroism, formula (9) does not represent that (x y) along the line integral of certain bar straight line, thereby does not satisfy the requirement of CT mathematical principle to μ.Conventional reconstruction algorithm is ignored this inconsistency, and (x, y) image contains the pseudo-shadow of cup-shaped, is called the pseudo-shadow of sclerosis to rebuild the μ that obtains.
Existing dual intensity CT method adopt earlier conventional reconstruction algorithm obtain two groups of μ (x, y), information such as calculation of atomic ordinal sum density then.But can not eliminate the pleochromatic influence of ray like this.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 projection value expression formula based on the sill coefficient:
p = - ln ∫ 0 E m S ( E ) exp ( - ∫ l [ μ 1 ( E ) b 1 ( x , y ) + μ 2 ( E ) b 2 ( x , y ) ] dl ) dE - - - ( 10 )
The integration of l along the path 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 2(x, projection y).Supposed to get access to the complete sill coefficient projection under each angle, so just can rebuild and obtain sill coefficient b according to the CT reconstruction theory 1And b 2Distribution, thereby distribute and the line attenuation coefficient value under the energy arbitrarily according to atomic number and the characteristic density that the sill decomposition model calculates object.
● 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 ( B 1 , B 2 ) = - ln ∫ 0 E 1 S 1 ( E ) exp [ - B 1 μ 1 ( E ) - B 2 μ 2 ( E ) ] dE - - - ( 13 )
p 2 ( B 1 , B 2 ) = - ln ∫ 0 E 2 S 2 ( E ) exp [ - B 1 μ 1 ( E ) - B 2 μ 2 ( E ) ] dE - - - ( 14 )
Measuring (p 1, p 2) after, can find the solution according to equation (13) and (14) and obtain (B 1, B 2).But, can't resolve and find the solution because above-mentioned two equations are the logarithmic integral equation.The common calculated amount of nonlinear iteration method for solving is very big, 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 such as the following expression that measure:
p 1 = - ln ∫ 0 E 1 S 1 ( E ) exp [ - d 1 μ 1 ( E ) - d 2 μ 2 ( E ) ] dE - - - ( 15 )
p 2 = - ln ∫ 0 E 2 S 2 ( E ) exp [ - d 1 μ 1 ( E ) - d 2 μ 2 ( E ) ] dE - - - ( 16 )
Contrast (13), (14) and (15), (16) can find out that 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 (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.
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 Processing.
At step S511, extract the checking matter (prospect comprises liquid and packing thereof) in the CT image of level and smooth back, 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 seized liquid article and atomic number are then relatively large because the density and the atomic number of air are almost 0.
At step S512, extracting liq pixel in foreground pixel.Concrete grammar can be: at first set up a bianry image of scheming correspondence with CT, the value of foreground pixel is 1, and 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 through repeatedly corroding step by step.The number of times of corrosion can be set through realizing the thickness of confirming packing material.
At step S513, the average density and the average atomic number of all liq pixel among the statistics CT figure are as the output result of this measurement.
In addition, if confirm that in the DR image analysis process liquid state is layering, then carries out aforesaid step to every layer of liquid, and then judges whether each layer liquid is suspicious.Finally, report final check result to the operator.
[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 many liquid articles simultaneously in detail below in conjunction with Figure 15～18.The difference of second embodiment and first embodiment is; Because there are many liquid articles; Need be after the CT imaging be accomplished; The position of the object on the position of the imaging results that shows on the display and load carrier is corresponding, understands fully that part liquid article is dangerous material thereby be convenient to the operator.Figure 15 A and Figure 15 B show the synoptic diagram of the CT image of rebuilding under the situation according to many liquid articles of detection of second embodiment of the invention.
For example, the operator observes the checking matter on the load carrier with the mode of overlooking, and this just requires to check that the position of finishing each object on each layer CT image of back must be consistent with the load carrier vertical view.
Figure 16 A-16K shows after the CT imaging is accomplished, and how CT reconstructed image and/or load carrier is rotated itself and the CT scan corresponding to process of relative position of object before that makes.
Figure 16 A showed in CT when beginning imaging first time, and the vertical view of load carrier 40 is wherein with the angle of arrow indication load carrier.Figure 16 B shows the CT image before the CT image rotation first time, and the vertical view of its load carrier during with imaging beginning for the first time is consistent, and dotted line wherein identifies the rotating range of load carrier.Figure 16 C shows at the postrotational image of ground floor CT image, because the anglec of rotation is zero, therefore in fact need not this layer CT image is rotated.
Figure 16 D shows when the n time CT imaging beginning, the vertical view of load carrier.Can find out that from Figure 16 D when the n time CT imaging beginning, load carrier is than the preceding situation of the CT imaging first time, with an angle.Figure 16 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 16 F shows the image among Figure 16 D is rotated, and makes the synoptic diagram of itself and ground floor CT image alignment.
When Figure 16 G shows the last time CT imaging beginning, the vertical view of load carrier, the load carrier that can find out this moment during than first time CT imaging beginning with an angle.Figure 16 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 16 I shows the image among Figure 16 H is rotated, and makes the synoptic diagram of itself and ground floor CT image alignment.
After Figure 16 J showed last CT imaging end, the vertical view of load carrier wherein than CT imaging beginning first time situation before, had an anglec of rotation.Figure 16 K shows and finishes the back in imaging that load carrier is rotated the image that itself and CT is for the first time formed images obtained is consistent.
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 (this angle can obtain through angle information acquiring unit 54) during according to each time CT imaging beginning; 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, the angle of adjustment load carrier is consistent the vertical view of load carrier and CT image.
For example, suppose to have carried out altogether N CT imaging, the load carrier angle is α during the n time CT imaging beginning 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, only need load carrier by counter clockwise direction anglec of rotation 360-(β in order to make object N-α 1) get final product.
Figure 17 shows the process flow diagram of under the situation of many seized objects, checking.Shown in figure 17, at step S711, the operator powers on to system, and login inspection interface, gets into 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.
Next, at step S712, the operator presses start button and begins according to carrying out DR scanning with identical as stated mode, to generate the DR image.
After obtaining the DR image, at step S713A, the DR image is analyzed, confirm the scanning position of CT imaging automatically, 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 confirmed CT scan, carry out the CT scan process at step S714, just carry out CT scan to above-mentioned definite position liquid towards article, obtain the CT scan data, and rebuild the CT image according to reconstruction algorithm.Each pixel of this CT image has been represented the density and the atomic number of appropriate section in the liquid article.Exist when liquid under the situation of multilayer, carry out CT scan to 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 image), is consistent (such as consistent) with the physical location of object on load carrier simultaneously, so that distinguish object B and object A with vertical view.
At step S717; Every layer of CT image carried out image segmentation handle (such as using watershed algorithm); Obtain the wherein liquid regions of every checking matter; The density and the atomic number average of each pixel in each liquid regions of step S718 statistics; Step S719 judge to the measured density of each liquid regions and atomic number true point whether dropped in the presumptive area in density-atom coefficient coordinate space, whether this layer liquid at this part checking matter of step S720 differentiation is dangerous material in view of the above.
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 the safety risk article 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 colorize handle 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.
More than explanation is the situation of checking two liquid articles simultaneously; In the time will checking more liquid articles simultaneously, see the position of understanding each liquid article for the ease of operating personnel, shown in figure 18; Mark off a plurality of zones on the surface to load carrier carrying liquid article; For example the A district among Figure 18, B district, C district and D district, operating personnel can be placed on each part liquid article in the corresponding zone like this, and to importing fluid identification information separately in each zone.
[the 3rd embodiment]
In order further to improve detection efficiency and to prevent that elongated seized liquid article from directly placing the problem that is easy to generate instability when causing detecting on the load carrier and influences the detection effect, the 3rd embodiment proposes many objects are placed in the lattice bucket.
Therefore, the difference of the 3rd embodiment and second embodiment is, in the process of many objects of inspection, has used the lattice bucket.Specify specific operation process below in conjunction with accompanying drawing 19～24 according to the checkout equipment of this embodiment.
Figure 19 shows the side view according to the lattice bucket of this embodiment, and Figure 20 shows the vertical view of lattice bucket, and Figure 21 shows the backplan of lattice bucket.
Shown in figure 19, lattice bucket 70 comprises bottom and the sidewall that is coupled with the bottom.The lower surface of bottom is provided with the convexity 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 between the two, to produce relative motion with load carrier 40 rotations.
In addition, shown in figure 19, be provided with flange, handled easily person's grasping and carrying in one week of top of sidewall.Sidewall is columned or taper, and can be by having the elastic sides material, and for example tygon (PE) or aluminium are processed.
Figure 20 is the vertical view of three kinds of lattice buckets.As shown in the figure, in the space that forms 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 for the placement 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 on the outside surface of sidewall, mark be set, be convenient to when detecting detecting the location of article in the bucket.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 is provided with on the sidewall, coming to user report is that which part article is suspicious.
For example, shown in the left hand view of Figure 20, be provided with the mark that the cross section is the circle of preliminary dimension at the upside of lattice parts, the perhaps length of certain lattice parts little than other is thus as the used mark of location liquid article.
Figure 21 is the backplan of lattice bucket.On the lower surface of bottom, be evenly distributed with three convexities.But these three protruding distributions also can be uneven.
Figure 22 shows the process that in checking process, how to detect lattice bucket and mark automatically.As stated, the lattice tube has specific structure, can use the method for masterplate coupling commonly used in the Flame Image Process to detect.First kind of bucket with band cross lattice is example, can at first set up the template image that a width of cloth has cross at step S810, and the center of this template is placed CT picture centre to be identified, obtains matching value.
At step S811, whether judge this matching value then, if the result negates that then back rotary template image is till the matching degree maximum of template image and CT image greater than predetermined threshold value.If matching degree, thinks then that there is the lattice tube in CT in scheming greater than certain pre-set threshold, otherwise think that there is not the lattice tube in CT in scheming.
If have the lattice tube among the CT figure, can further come the detection and location mark at step S812 according to specifically labelled characteristics.Still first kind of tube with band cross lattice is example, and 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 tube among the CT figure, the cross curve when matching degree is maximum in the template image just in time overlaps with frame bar; Through the length of four frame bars relatively, extract wherein the longest one, can obtain telltale mark.
After the multi-Slice CT imaging, at first each layer CT image is carried out detection of lattice tube and telltale mark detection.If all do not detect the lattice tube in each layer CT image, think that then the operator does not use the lattice tube; If detecting the lattice tube in one deck CT image at least, think that then the operator has used the lattice tube; If differ in the detected telltale mark of each layer position, a maximum telltale mark that conduct is final of signal intensity 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 big more, and the telltale mark signal is strong more.
Figure 23 A-23D shows the synoptic diagram of rotary barrel in testing process.The telltale mark that only needs lattice to be detected tube is adjusted to the precalculated position, can each lattice be adjusted to assigned address.With first kind of cross lattice tube is example, is that coordinate origin is set up polar coordinate system with the CT picture centre, and the position of each lattice is confirmed by specifically labelled angle coordinate is unique.Supposing the system final pairing polar angle of telltale mark of confirming in various CT images is γ; And the predefined adjustment target of system is θ; So only need each layer CT image and load carrier anglec of rotation θ-γ can be accomplished adjustment, be illustrated in fig. 24 shown below.
Shown in Figure 23 A and 23B, with angle of lattice bucket rotation, to reach the position that requires in advance.Equally, every layer of CT resulting image that forms images is rotated, makes its angle consistent with postrotational lattice bucket.
Figure 24 shows the process flow diagram according to the checking process of this embodiment.Because the step S711 with above-mentioned the 3rd embodiment is identical to step S721 from step S911 to step S921, step S922 is only described here to step S926.
At step S922, analyze the CT image, in step S923 judges, whether have lattice and detect tube.If do not detect tube, then this inspection finishes.
Detect bucket if used, then detect the telltale mark of tube, confirm the position of each lattice in step S924 identification.At step S925 load carrier angle and each layer CT image angle are carried out adjustment second time then, with the position of each lattice in detecting on the load carrier tin, and the position of each lattice on each layer of liquid CT image, all adjust 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, gathers into the inspection conclusion of each lattice and is prompted to the user.A kind of method of summary according to this 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 ".
[modification 1]
Though abovely carry out CT then and be imaged as example embodiments of the invention are illustrated to carry out DR imaging earlier, also can directly carry out spiral CT and form images, come the liquid towards article to check.
It is one group of spiral CT image that the liquid towards article carry out the spiral CT inspection resulting; Through relatively and analyze the pixel in this group CT image; Just can confirm the position of liquid in the liquid article; And whether layering of liquid, utilize the physical property values that obtains the liquid of each layer position with the similar method of as above describing then, for example density and atomic number.For example liquid article shown in figure 25 is being carried out spiral CT when imaging,, will obtain one group of CT image shown in Figure 26 A-26M if be that screw pitch scans with 2cm.Like this, through analyzing the pixel 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.
Equally, as those of ordinary skill in the art institute clearly, above-mentioned variant embodiment also can be applied to many bottles of detections as second embodiment and the 3rd embodiment.
In addition, though top be that example is illustrated with density and atomic number, the present invention can only use one of density or atomic number to carry out equally, perhaps uses other more physical attributes to carry out the identification of dangerous material.In the former case; In checking process; Judge in the predetermined scope through judging whether a kind of physical property values drops on whether liquid is dangerous material; Under latter event, in checking process, judge through judging whether to drop on to draw in the presumptive area in the hyperspace that limits these attributes whether liquid is dangerous material the determined point of multiple physical property values.
[modification 2]
Though it is above to carry out the DR imaging earlier; Carrying out dual intensity CT then forms images and obtains density of liquid and atomic number; But the imaging of the DR here is not necessary; Because can come to specify in advance preposition to carry out dual intensity CT imaging to different liquid articles, obtain density of liquid and atomic number.
Top description only is used to realize embodiment of the present invention; It should be appreciated by those skilled in the art; In any modification that does not depart from the scope of the present invention or local replacement; 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 of checking with dual intensity CT liquid towards article comprises step:
Carry out the transmission image that DR scanning obtains seized liquid article to liquid article;
Analyze the pixel value of said transmission image, to confirm the whether layering of said transmission image;
The dual intensity CT scan is carried out to seized liquid article at least one position in determined each layer, obtains dual intensity CT data for projection, and wherein, said dual intensity CT scan adopts the mode of plane fault CT scan;
Carry out CT according to said data for projection and rebuild, obtain representing the CT image of the physical property values of seized liquid article;
Extract the physical property values of seized liquid article according to said CT image; And
Judge based on said physical property values whether said seized liquid article is dangerous material.
2. the method for claim 1, wherein said physical property values comprises the density and the atomic number of seized liquid article.
3. the method for claim 1 is appointed as the middle line in each layer the position that will carry out the dual intensity CT scan.
4. method as claimed in claim 3, obtain transmission image after, confirm the middle line of each layer in the transmission image automatically through image processing techniques, as the CT scan position.
5. method as claimed in claim 4, the step that wherein forms transmission image comprises:
Send high-energy ray and low energy ray from radiographic source, penetrate seized object, form high energy transmission image and low energy transmission image;
Merge high energy transmission image and low energy transmission image, form said transmission image.
6. method as claimed in claim 4, the step that wherein forms transmission image comprises:
Send high-energy ray and low energy ray from radiographic source, penetrate seized object, form high energy transmission image and low energy transmission image;
Select one of high energy transmission image and low energy transmission image, as said transmission image.
7. the method for claim 1 wherein comprises from the step of CT image that the dual intensity data for projection is rebuild the physical property values of the seized liquid article of expression:
According to high low energy data for projection, generate data for projection about two kinds of sill coefficients;
Data for projection according to said two kinds of sill coefficients is rebuild, and obtains representing the CT image of the pairing two kinds of sill coefficients of seized liquid; And
According to said expression sill coefficient CT image, generate the CT image of the seized liquid article physical property values of said expression.
8. the method for claim 1, wherein according to the CT image of the physical property values of the seized liquid article of expression, the step that obtains seized liquid article physical property values comprises:
From said CT image, extract and the corresponding pixel of liquid part;
To the pixel bulk density average and the atomic number average of liquid part, as the density and the atomic number of said seized liquid article.
9. the method for claim 1, wherein judge that based on said physical property values whether said seized liquid article is that the step of dangerous material comprises:
Judge whether the determined point of density and atomic number drops in the presumptive area in density-atomic number two-dimensional coordinate space;
Drop under the situation in the said presumptive area at said point, think that said seized liquid article is dangerous material.
10. the method for claim 1 wherein after carrying out the dual intensity CT scan to 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 to each row, is rotated seized 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 to come to detect automatically the existence of bucket;
Under the situation that has bucket, detect the specific markers in the CT image;
Based on said specific markers, bucket is rotated to preposition.
14., also comprise step like claim 11 or 13 described methods:
With the judgment result displays of seized liquid article on display screen.
15., also comprise step like claim 11 or 13 described methods:
The judged result of each seized liquid article is printed.
16., also comprise step like claim 11 or 13 described methods:
CT image colorization with each seized liquid article.
17. an equipment of checking with dual intensity CT liquid towards article comprises:
Radiographic source is used to send ray;
Survey and harvester, be used to survey and gather the ray signal that penetrates at least one seized liquid article;
Controller is controlled said radiographic source and detection and harvester seized liquid article is carried out DR scanning, obtains the transmission image of seized liquid article;
Analyze the pixel value of said transmission image; To confirm the whether device of layering of said transmission image; Wherein said controller is controlled said radiographic source and detection and harvester at least one position in determined each layer seized liquid article is carried out the dual intensity CT scan; Obtain dual intensity CT data for projection, wherein, said dual intensity CT scan adopts the mode of plane fault CT scan;
Said equipment also comprises:
Rebuild the device of the CT image of at least a physical property values of representing seized liquid article from data for projection; And
Judge based on the position of said physical property values in the space of respective dimensions whether said seized liquid article is the device of dangerous material.
18. equipment as claimed in claim 17, wherein said physical property values comprise the density and the atomic number of seized liquid article at least.
19. equipment as claimed in claim 17 wherein sends high-energy ray and low energy ray from radiographic source, penetrates seized object, forms high energy transmission image and low energy transmission image, said equipment also comprises:
Merge the device that high energy transmission image and low energy transmission image form said transmission image.
20. equipment as claimed in claim 17 wherein sends high-energy ray and low energy ray from radiographic source, penetrates seized object, forms high energy transmission image and low energy transmission image, said equipment also comprises:
Select one of high energy transmission image and low energy transmission image, as the device of said transmission image.
21. equipment as claimed in claim 17, wherein
Middle line in each layer is appointed as the row that will carry out the dual intensity CT scan.
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 seized liquid article of expression:
Fusion is by the density image that density identified of seized liquid article with by the atomic number image that atomic number identified of the seized liquid article device as said CT image;
From said CT image, extract and the corresponding pixel of liquid part;
To the pixel bulk density average of liquid part and atomic number average as the density of said seized liquid article and the device of atomic number.
23. equipment as claimed in claim 17 wherein judges that based on said physical property values whether said seized liquid article is that the device of dangerous material comprises:
Judge whether the determined point of density and atomic number drops on the device in the presumptive area in density-atomic number two-dimensional coordinate space, wherein, drops under the situation in the presumptive area at said point, thinks that said seized liquid article is dangerous material.
24. equipment as claimed in claim 17 also comprises: to after every row carries out the dual intensity CT scan, 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 to each row and carries out rotating seized liquid article after the dual intensity CT scan, makes itself and the scanning identical device in position before.
26. equipment as claimed in claim 17 also comprises bucket, has been divided into a plurality of spaces, is respectively applied for to place said liquid article.
27. equipment as claimed in claim 26 comprises:
Utilize predetermined template to come to detect automatically the device of the existence of bucket;
Under the situation that has bucket, detect the device of the specific markers in the CT image;
Based on said specific markers, bucket is rotated to the device of preposition.
28., also comprise like claim 25 or 27 described equipment:
Display device shows the judged result of seized liquid article.
29., also comprise like claim 25 or 27 described equipment:
The device that the judged result of each seized liquid article is printed.
30., also comprise like claim 25 or 27 described equipment:
Device with the CT image colorization of each seized liquid article.
31. equipment as claimed in claim 17 also comprises the load carrier that carries said seized liquid article, said load carrier carries on the surface of said seized liquid article and is divided into the discernible a plurality of zones of operating personnel.
CN 201010621640 2007-10-05 2007-10-05 Method and equipment for checking liquid object Active CN102095666B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN 201010621640 CN102095666B (en) 2007-10-05 2007-10-05 Method and equipment for checking liquid object

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN 201010621640 CN102095666B (en) 2007-10-05 2007-10-05 Method and equipment for checking liquid object

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
CN2007101806528A Division CN101403710B (en) 2007-10-05 2007-10-05 Liquid article examination method and equipment

Publications (2)

Publication Number Publication Date
CN102095666A CN102095666A (en) 2011-06-15
CN102095666B true CN102095666B (en) 2012-12-12

Family

ID=44128847

Family Applications (1)

Application Number Title Priority Date Filing Date
CN 201010621640 Active CN102095666B (en) 2007-10-05 2007-10-05 Method and equipment for checking liquid object

Country Status (1)

Country Link
CN (1) CN102095666B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104749157B (en) * 2013-12-27 2019-02-19 同方威视技术股份有限公司 The method and apparatus that safety inspection is carried out to liquid article
CN105910956B (en) * 2016-04-15 2019-02-26 中国科学院上海硅酸盐研究所 A kind of method of industry CT object analysis density and Density Distribution
CN107957428A (en) * 2017-11-29 2018-04-24 合肥赑歌数据科技有限公司 One kind is based on DSP adapting to image energy decline processing method

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5367552A (en) * 1991-10-03 1994-11-22 In Vision Technologies, Inc. Automatic concealed object detection system having a pre-scan stage
US6418189B1 (en) * 2000-01-24 2002-07-09 Analogic Corporation Explosive material detection apparatus and method using dual energy information of a scan
CN1779444A (en) * 2004-11-26 2006-05-31 清华大学 Safety CT inspection and inspector for liquid by ray resource
CN1779451A (en) * 2004-11-26 2006-05-31 清华大学 Back scattering safety inspection and inspector for liquid by radioactive resource
CN1779443A (en) * 2004-11-26 2006-05-31 清华大学 Safety liquid inspection and inspector by radioactive resource

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004177138A (en) * 2002-11-25 2004-06-24 Hitachi Ltd Dangerous object detector and dangerous object detection method
EP1609004A2 (en) * 2003-04-02 2005-12-28 Reveal Imaging Technologies, Inc. System and method for detection of explosives in baggage

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5367552A (en) * 1991-10-03 1994-11-22 In Vision Technologies, Inc. Automatic concealed object detection system having a pre-scan stage
US6418189B1 (en) * 2000-01-24 2002-07-09 Analogic Corporation Explosive material detection apparatus and method using dual energy information of a scan
CN1779444A (en) * 2004-11-26 2006-05-31 清华大学 Safety CT inspection and inspector for liquid by ray resource
CN1779451A (en) * 2004-11-26 2006-05-31 清华大学 Back scattering safety inspection and inspector for liquid by radioactive resource
CN1779443A (en) * 2004-11-26 2006-05-31 清华大学 Safety liquid inspection and inspector by radioactive resource

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
W. A. Kalender et.al..Evaluation of a prototype dual-energy computed tomographic apparatus.I.Phantom studies.《Medical Physics》.1986,第13卷 *
王琪等.X射线安全检查技术综述.《CT理论与应用研究》.2004,第13卷(第1期),32-37. *

Also Published As

Publication number Publication date
CN102095666A (en) 2011-06-15

Similar Documents

Publication Publication Date Title
CN101403710B (en) Liquid article examination method and equipment
CN101403711B (en) Liquid article examination method and equipment
CN102608135B (en) Method and equipment for confirming CT (Computed Tomography) scanning position in dangerous goods inspection system
CN100483120C (en) Method and equipment for safety-checking liquid stage article with ray
CN102162798B (en) Method and equipment for inspecting liquid article
WO2017012562A1 (en) Method and apparatus for estimating weight of inspected object in safety inspection system
CN102565107B (en) Liquid article inspection method and equipment
CN102095663B (en) Method and equipment for inspecting liquid substances
CN102435620A (en) Method and device for checking liquid articles
CN102095666B (en) Method and equipment for checking liquid object
CN102095664B (en) Method and device for checking liquid article
CN102095665B (en) Method and equipment for inspecting liquid substances
CN102147376B (en) Liquid article detection method and device
CN102590239B (en) Method and equipment for determining computerized tomography (CT) scanning position in drug inspection system
CN102565102B (en) Liquid item inspection method and equipment
CN102539455A (en) Examination method and examination equipment for liquid articles
Kansouh et al. Effectiveness of X and Gamma Rays for Scanning Cargo Containers
Miller et al. Combining radiography and passive measurements for radiological threat detection in cargo

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant