CN103226114B - Various visual angles stereoscopic radiation imaging system and method - Google Patents

Abstract

The invention discloses a multi-view stereoscopic radiation imaging system and method. The system includes: a radiation source and a collimator that emit radiation and form at least two radiation beams after passing through a collimator, wherein any adjacent two radiation beams The included angle is 3 degrees to 15 degrees; the detector system that receives the rays passing through the object to be inspected and converts them into data signals and sends them to the image data acquisition system; the data processing system that processes the image data; the processed image An image display system for display, wherein: the detector system includes at least two groups of detector arrays, the images obtained by any two groups of detectors can generate a stereoscopic image of a certain viewing angle, and the images obtained by multiple groups of detectors can obtain multiple viewing angles Stereoscopic image. Compared with the single-view detection device, the present invention realizes multi-view stereoscopic imaging of the object to be inspected through a plurality of detector arrays and collimators, which can distinguish the overlapping objects inside the object and determine the specific position of the suspicious object, improving the Test your ability.

Description

Multi-view stereo radiation imaging system and method

technical field

The invention relates to the technical field of radiation imaging, in particular to a multi-view stereo radiation imaging system and method.

Background technique

The large-scale object stereoscopic imaging detection device is an upgraded product of conventional container, freight train and motor vehicle detection technology. Requirements, radiation imaging detection systems for containers, motor vehicles and freight trains are equipped in large quantities and exported to many countries.

Currently widely used radiation imaging detection systems for containers, freight trains and cars all use a single row of detector arrays. The system composition is shown in Figure 1. The radiation emitted by the radiation source 11 is collimated by the collimator 12 into a fan-shaped radiation beam. After passing through the object 13 to be inspected, the transmitted radiation is measured by the linear detector array 14 , the object 13 to be inspected moves along a direction perpendicular to the ray beam, and the data acquisition and image display system 15 generates a perspective image through scanning. This method can only obtain perspective images of one viewing angle at a time, and cannot distinguish overlapping objects before and after, and cannot determine the specific location of suspicious objects because there is no depth information.

In recent years, a kind of left and right perspective images obtained by using two detector arrays with a certain angle as described in the Chinese invention patent CN101210895B "A Method and System for Scanning Radiation Imaging with Two Views" is developed. The image data is segmented and matched, and a tomogram of the perspective view in the depth direction is built to form a perspective image with depth information, which can identify objects at different depths. Since the shapes, positions, and varieties of the items in the container are different and cannot be known in advance, it is very difficult for this method to perform image segmentation and spatial positioning of the items of interest, and the image recognition effect is not ideal. not big.

Contents of the invention

(1) Technical problems to be solved

The technical problem to be solved by the present invention is to provide a multi-view stereo radiation imaging system and method for the deficiencies of the prior art, which uses the principle of binocular stereo imaging of human eyes to realize the stereoscopic imaging of the object under inspection through binocular stereo imaging technology. Imaging can observe the object in the area of interest inside the object from different angles, so as to obtain the shape, spatial position and internal structure information of the object, and provide a basis for judging contraband, dangerous goods and smuggled goods.

(2) Technical solution

The invention provides a multi-view stereo radiation imaging system, comprising: a ray source, a collimator, a detector system, an image data acquisition system, a data processing system and an image display system;

The ray source emits rays and generates at least two ray beams through a collimator;

The detector system receives the rays passing through the inspected object, converts them into data signals and sends them to the image data acquisition system;

The image data collection system sends the collected image data to a data processing system;

The data processing system processes image data and sends the processed image to the image display system;

The detector system includes at least two groups of detector arrays; the included angle between any two adjacent ray beams in the ray beams formed after the rays emitted by the ray source pass through the collimator is 3 degrees to 15 degrees.

Wherein, the included angle between any two adjacent ray beams is 8 degrees to 9 degrees.

Wherein, the ray source is an X-ray machine ray source, an isotope ray source or an accelerator X-ray source.

Wherein, the detector array is a gas-filled ion chamber detector array, a scintillator detector array or a semiconductor detector array.

The present invention provides a method for generating a stereoscopic radiation image using the above-mentioned multi-view stereoscopic radiation imaging system, comprising the following steps:

S1: The ray source emits rays and generates at least two ray beams through the collimator, and the angle between any two adjacent ray beams is 3 degrees to 15 degrees;

S2: Each group of detector arrays of the detector system receives the rays that enter the detector array after passing through the inspected object, generates image signals and sends them to the image data acquisition system;

S3: the image data acquisition system receives the image signal and sends it to the data processing system;

S4: the data processing system processes the data signal, returns to S2 and repeats S2-S4 until images obtained by all detector arrays are generated;

S5: Among the images obtained by the detector array described in S4, select the images obtained by two sets of detector arrays corresponding to any two ray beams with an angle not greater than 30 degrees, generate a stereoscopic image, and send the stereoscopic image to image display system.

Among them, in S1, as long as the angle between any two adjacent ray beams is between 3 degrees and 15 degrees, the perspective images obtained by the corresponding two sets of detector arrays can generate a certain observation angle. Stereoscopic images, the stereoscopic images can meet the observation requirements of human eyes, and can achieve the purpose of the present invention. However, as the included angle increases, the correlation of the perspective images obtained by the corresponding two sets of detector arrays becomes smaller, and the image quality and observation effect of the stereo imaging become worse. Therefore, in order to further improve the quality of the stereoscopic image and ensure an excellent detection effect, the included angle is preferably 8 degrees to 9 degrees.

Wherein, in S2, after the detector system receives the ray passing through the object to be inspected and generates the image signal, the signal is sent to the image data acquisition system through an amplifier.

Wherein, each stereoscopic image generated in S5 is formed by converting the images obtained by two sets of detector arrays into a left analog view and a right analog view respectively.

In S5, the method for generating the stereoscopic image is: color division method, light division method, time division method or holographic method.

The multi-view stereo radiation imaging system and method of the present invention can be used to detect large objects such as containers, freight trains, and motor vehicles, as well as small objects such as suitcases and hand luggage.

(3) Beneficial effects

Compared with the single-view detection device, the present invention realizes multi-view stereoscopic imaging of the object to be inspected through a plurality of detector arrays and collimators, and can distinguish the overlapping objects inside the object, determine the specific position of the suspicious object, and improve detection capability.

Description of drawings

1 is a schematic diagram of the composition of a single-row detector array radiation imaging system in the prior art;

Fig. 2 is a structural block diagram of the multi-view stereo radiation imaging system of the present invention;

Fig. 3 is a flow chart of the steps of the multi-view stereo radiation imaging method of the present invention;

Fig. 4 is a functional block diagram of the multi-view stereo radiation imaging method of the present invention;

Fig. 5 is an algorithm flow chart of the multi-view stereo radiation imaging method of the present invention.

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are only used to illustrate the present invention, but not to limit the scope of the present invention.

As shown in Figure 2, the multi-view stereo radiation imaging system of the present invention includes: a ray source 21, a collimator 22, a detector system 24, an amplifier 25, an image data acquisition system 26, a data processing system 27 and an image display system 28 .

The radiation source 21 emits radiation and passes through a collimator 22 to generate at least two radiation beams. The radiation source 21 is an X-ray source, an isotope radiation source or an accelerator radiation source.

The detector system 24 receives the rays passing through the object to be inspected, and converts them into data signals and sends them to the image data acquisition system 26 .

The amplifier 25 receives the data signal sent by the detector system 24 and amplifies the data signal before sending it to the image data acquisition system 26 .

The image data collection system 26 sends the collected image data to the data processing system 27 .

The data processing system 27 processes the image data and sends the processed image to the image display system 28 .

The detector system 24 includes at least two groups of detector arrays; the included angle between any two adjacent ray beams in the ray beam formed after the ray emitted by the ray source passes through the collimator 22 is 3 degrees to 15 degrees , Preferably, the included angle between any two adjacent ray beams is 8 degrees to 9 degrees. The detector array is a gas-filled ion chamber detector array, a scintillator detector array or a semiconductor detector array.

As shown in Figure 3, the present invention also provides a method for generating a stereoscopic radiation image using the above-mentioned multi-view stereoscopic radiation imaging system, including:

S1: The radiation source emits radiation and generates at least two radiation beams through the collimator, and the angle between any two adjacent radiation beams is 3 degrees to 15 degrees. Preferably, the included angle between any two adjacent ray beams is 8 degrees to 9 degrees.

S2: Each group of detector arrays of the detector system receives the rays that enter the detector array after passing through the inspected object, generates image signals and sends them to the image data acquisition system.

In order to improve the quality of the image data signal, the detector system converts the rays passing through the inspected object into data signals, and sends them to the image data acquisition system through the amplifier.

S3: the image data acquisition system receives the image signal and sends it to the data processing system;

S4: the data processing system processes the data signal, returns to S2 and repeats S2-S4 until images obtained by all detector arrays are generated;

S5: According to the images obtained by all the detector arrays in S4, select the images obtained by two sets of detector arrays corresponding to any two ray beams with an angle not greater than 30 degrees, generate a stereoscopic image, and send the stereoscopic image to the image display system. Since the images obtained by any two sets of detector arrays with an angle less than 30 degrees can generate a stereoscopic image at a certain viewing angle, for N sets of detector arrays, at most C _N ² =N*(N-1)/ Stereoscopic images from 2 different viewing angles. By comprehensively observing these stereoscopic images from different observation angles, the shape information, spatial information and structural information of the region of interest inside the object to be inspected can be further obtained, and the detection effect can be further improved.

In S5, the method for generating a stereoscopic image includes: commonly used stereoscopic image imaging methods such as color division method, light division method, time division method, or holographic method. Each stereoscopic image generated is formed by converting the images obtained by the two sets of detector arrays into left and right analog views, respectively.

The difference between the present invention and the prior art is that besides using two or more detector arrays, one stereoscopic image at a certain observation angle can be formed, and multiple stereoscopic images at different observation angles can also be formed, so that the detected Distinguish between different objects that overlap front and back inside the object.

The basic principle of the stereoscopic imaging of the present invention is shown in Figure 4. Utilizing the binocular stereoscopic imaging principle of the human eye, the rays of the ray source 41 pass through the object 42 to be inspected, and two angles are obtained by using the left detector array 43 and the right detector array 44. By converting the binocular observation effect of the simulated person, using the stereoscopic image display system to let the left and right eyes observe the two images separately, that is, the left simulated view is observed by the left eye, and the right simulated view is observed by the right eye alone, then it can produce A three-dimensional image of an object. The angles (45, 46) between the ray beams corresponding to the left detector array 43 and the right detector array 44 and perpendicular to the scanning direction can be equal or different. Squint at objects with both eyes. The included angle between the two ray beams in the present invention is the sum of the included angle 45 and the included angle 46 .

Fig. 5 is an algorithm flow chart of the multi-view stereo radiation imaging method of the present invention. As shown in Figure 5 and referring to Figure 4, using the included angle (45, 46), the equivalent stereoscopic viewing angle (that is, the viewing angle) θ=(Included angle 45+Included angle 46)/2 can be calculated, according to user input The simulated interpupillary distance L of the human eye or determined by empirical data, the equivalent viewing distance D=L*ctan(θ)/2 is calculated from the equivalent stereoscopic viewing angle θ and the simulated interpupillary distance L. According to the acquisition time of the two sets of detectors, the spatial distance of the arrangement and the scanning speed, the images collected by the two sets of detectors are aligned along the scanning direction, and according to the geometric structure of the two sets of detector arrays, the image is stretched and transformed along the detectors. The direction of extension of the array (which is perpendicular to the scanning direction) is aligned. According to the equivalent observation distance D and the simulated interpupillary distance L, the image data obtained by the right detector is shifted to the right by L/D times of the image width after alignment, and the shifted part is filled with medium gray as the left analog view; after alignment The position of the image data obtained by the left detector remains unchanged, the tail of the image is filled with medium gray, and the image width is consistent with the left analog view, which is used as the right analog view. After obtaining the left and right simulated views, input them into the stereoscopic image display system, and use the principle of binocular stereoscopic imaging to generate a three-dimensional stereoscopic image. Human eyes can observe the stereoscopic image with the help of 3D glasses.

The present invention utilizes the above-mentioned stereoscopic imaging principle, not only can use the perspective images generated by any two groups of adjacent detector arrays to generate a stereoscopic image at a certain viewing angle, but also can select any two groups of non-adjacent detectors with an included angle not greater than 30 degrees. The perspective image generated by the detector array generates multiple stereoscopic images of different viewing angles, thereby obtaining multiple scanning perspective stereoscopic images of a certain area of interest inside the object to be inspected, which is used to inspect objects such as containers, freight trains, and aircraft without opening the box. Large objects such as motor vehicles, as well as contraband, dangerous goods, and smuggled goods inside small objects such as suitcases and hand luggage, provide more image information.

The above embodiments are only used to illustrate the present invention, but not to limit the present invention. Those skilled in the art can also make various changes and modifications without departing from the spirit and scope of the present invention. All equivalent technical solutions are Should belong to the category of the present invention.

Claims (7)

1. a various visual angles stereoscopic radiation imaging system, comprising: radiographic source, collimating apparatus, detector system, image data collection system, data handling system and image display system;

Described radiographic source, sends ray and generates at least two beam wire harness by collimating apparatus;

Described detector system, receives the ray through tested object, and is converted to data-signal and sends to described image data collection system;

Described image data collection system, sends to described data handling system by the view data collected;

Described data handling system, the image after process is also sent to described image display system by image data processing;

It is characterized in that, described detector system comprises at least two group detector arrays; The ray that described radiographic source sends is 8 degree ~ 9 degree by the angle between arbitrary neighborhood two beam wire harness in the beam that formed after collimating apparatus;

Described data handling system, also be not more than for choosing angle the image that two groups of detector arrays corresponding to any two beam wire harness of 30 degree obtain, generate stereo-picture, described stereo-picture is all converted to left simulated view respectively by the image obtained by two groups of detector arrays and right simulated view is formed.

2. the system as claimed in claim 1, is characterized in that, described radiographic source is X-ray machine radiographic source, isotope radiographic source or accelerator x-ray source.

3. the system as claimed in claim 1, is characterized in that, described detector array is classified as gas filled ionization chamber detector array, scintillator detector array or semiconductor detector array.

4. utilize the various visual angles stereoscopic radiation imaging system described in claim 1 to generate a method for stereoscopic radiation image, it is characterized in that, comprise the following steps:

S1: radiographic source sends ray and generates at least two beam wire harness by collimating apparatus, the angle between arbitrary neighborhood two beam wire harness is 8 degree ~ 9 degree;

S2: the detector array of often organizing of detector system receives through the ray entering this detector array after tested object, and synthetic image signal also sends to image data collection system;

S3: described image data collection system receives picture signal and sends to data handling system;

S4: described processing data of data processing system signal, returns S2 and repeat S2-S4, until the image generating the acquisition of all detector arrays;

S5: in the image that the detector array described in S4 obtains, chooses angle and is not more than the image that two groups of detector arrays corresponding to any two beam wire harness of 30 degree obtain, generate stereo-picture, and stereo-picture is sent to image display system.

5. method as claimed in claim 4, is characterized in that, in S2, described detector system receives the ray through tested object and after generating described picture signal, sends to described image data collection system by amplifier.

6. method as claimed in claim 4, is characterized in that, in S5, the method generating stereo-picture is: look point-score, light point-score, time-sharing procedure or holography method.

7. method as claimed in claim 4, is characterized in that, each stereo-picture generated in S5 is all converted to left simulated view respectively by the image obtained by two groups of detector arrays and right simulated view is formed.