CN111190238A - Security inspection method and device - Google Patents
Security inspection method and device Download PDFInfo
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- CN111190238A CN111190238A CN202010025981.0A CN202010025981A CN111190238A CN 111190238 A CN111190238 A CN 111190238A CN 202010025981 A CN202010025981 A CN 202010025981A CN 111190238 A CN111190238 A CN 111190238A
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- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V8/00—Prospecting or detecting by optical means
- G01V8/10—Detecting, e.g. by using light barriers
- G01V8/20—Detecting, e.g. by using light barriers using multiple transmitters or receivers
Abstract
The embodiment of the invention provides a security inspection method and device. Then, for each column of pixel points in the first terahertz image, calibration reference values of corresponding columns are respectively determined. And then, according to the calibration reference value, calibrating the pixel points in the corresponding row in the first terahertz image to obtain a second terahertz image, and displaying the second terahertz image. By adopting the scheme, the terahertz image with good quality is obtained by calibrating the terahertz image with poor quality, and the purpose of improving the accuracy of security inspection is realized by performing security inspection according to the terahertz image with good quality.
Description
Technical Field
The embodiment of the invention relates to the technical field of security inspection, in particular to a security inspection method and device.
Background
The wavelength of the terahertz wave is between the wavelength of infrared rays and the wavelength of millimeter waves, so that the terahertz wave has good penetrability on materials such as textiles and leather, and the formed image has higher spatial resolution; the terahertz wave is lower than the X-ray energy by several orders of magnitude and does not cause ionization damage to biological tissues, so the terahertz wave is widely applied to security inspection, such as customs inspection, airport inspection, station inspection and other public place inspection.
In the security inspection process based on terahertz, a terahertz array detector is used for scanning a detection object, so that a terahertz image of the detection object is obtained. Then, the terahertz image is analyzed to determine whether the detection object carries a controlled object, such as a knife, a gun, etc.
However, the terahertz array detector is generally a linear array terahertz detector composed of a plurality of terahertz detectors, and is influenced by characteristics of the terahertz array detector, and under the condition that input signals are the same, output signals of different terahertz detectors are different, so that quality of terahertz images acquired by the terahertz array detector is poor, security inspection accuracy is low, and safety accidents are easy to occur.
Disclosure of Invention
The embodiment of the invention provides a security inspection method and device, wherein a terahertz image with good quality is obtained by calibrating a terahertz image with poor quality, and security inspection is carried out according to the terahertz image with good quality, so that the purpose of improving the accuracy of security inspection is achieved.
In a first aspect, a security inspection method and apparatus provided in an embodiment of the present invention include:
scanning an object to be detected by using a terahertz array detector to obtain a first terahertz image;
for each column of pixel points in the first terahertz image, respectively determining a calibration reference value of a corresponding column;
calibrating pixel points in a corresponding row in the first terahertz image according to the calibration reference value to obtain a second terahertz image;
and displaying the second terahertz image.
In a feasible design, the terahertz array detector includes X terahertz detectors, the X terahertz detectors are arranged in a linear array, X is greater than or equal to 1, the first terahertz image includes X rows of pixel points, different terahertz detectors correspond to different rows of pixel points in the X rows of pixel points, and for each row of pixel points in the first terahertz image, calibration reference values corresponding to the rows are respectively determined, including:
determining a voltage value corresponding to each pixel point in a preset number of pixel points in an ith row of pixel points to obtain a preset number of voltage values, and taking an average voltage value of the preset number of voltage values as a calibration reference value of the ith row of pixel points, wherein the ith row of pixel points is any one row in the X rows of pixel points.
In one possible design, the calibration reference value is used. Calibrating pixel points in a corresponding column in the first terahertz image to obtain a second terahertz image, including:
for a jth pixel point in the ith row of pixel points, determining a voltage value corresponding to the jth pixel point, wherein the voltage value is obtained by amplifying an initial voltage obtained by radiating the object to be detected by an ith terahertz detector, and the ith terahertz detector is a terahertz detector corresponding to the ith row of pixel points;
determining an ith calibration parameter by using the voltage value corresponding to the jth pixel point, the calibration reference value of the ith row of pixel points and a coefficient ki, wherein the ith calibration parameter satisfies the following formula:
△Ti＝ki×(UHi-ULij) Wherein the △ Ti represents the ith calibration parameter, the UHiDenotes the ith calibration reference value, ULikRepresenting the voltage value of the jth pixel point in the ith row of pixel points;
and calibrating the pixel value of the j pixel point according to the i calibration parameter.
In a feasible design, before determining an ith calibration parameter by using the voltage value corresponding to the jth pixel point, the calibration reference value of the ith column of pixel points, and the coefficient ki, the method further includes:
acquiring sample data, wherein the sample data comprises Y pairs of data, each pair of data in the Y pairs of data comprises a temperature and a voltage value corresponding to the temperature, the temperature is the temperature of an ith terahertz detector radiating a black body radiation source, and the voltage value is an amplified voltage value of an initial voltage obtained by the ith terahertz detector radiating the black body radiation source;
determining a relation curve of the input temperature and the output voltage of the ith terahertz detector according to the Y pair of data to obtain ki, wherein the relation curve meets the following formula: t ═ Ai + kiU, where Ai denotes the intercept.
In a feasible design, the Y pair of data includes a temperature k and a voltage value m corresponding to the temperature k, where the voltage value m corresponding to the temperature k is an average value of amplified voltage values of a plurality of initial voltages obtained by the i-th terahertz detector radiating the black body radiation source when the temperature of the black body radiation source is the temperature k.
In a feasible design, after the calibrating, according to the calibration reference value, the method further includes:
judging whether the object to be detected carries a control tool or not according to the second terahertz image;
and when the object to be detected carries the control tool, outputting alarm information.
In a second aspect, an embodiment of the present application provides a security inspection apparatus, including:
the scanning module is used for scanning an object to be detected by utilizing the terahertz array detector to obtain a first terahertz image;
the determining module is used for respectively determining a calibration reference value of each corresponding column of pixel points in the first terahertz image;
the calibration module is used for calibrating pixel points in a corresponding row in the first terahertz image according to the calibration reference value to obtain a second terahertz image;
and the display module is used for displaying the second terahertz image.
In a feasible design, the terahertz array detector comprises X terahertz detectors, the X terahertz detectors are arranged in a linear array, X is larger than or equal to 1, the first terahertz image comprises X rows of pixel points, different terahertz detectors correspond to different rows of pixel points in the X rows of pixel points, the determining module is used for determining a voltage value corresponding to each pixel point in a preset number of pixel points in an ith row of pixel points to obtain a preset number of voltage values, an average voltage value of the preset number of voltage values is used as a calibration reference value of the ith row of pixel points, and the ith row of pixel points is any row of the X rows of pixel points.
In a feasible design, the calibration module is configured to determine a voltage value corresponding to a jth pixel point in the ith row of pixel points, where the voltage value is a voltage value obtained by amplifying an initial voltage obtained by an ith terahertz detector radiating the object to be detected, the ith terahertz detector is a terahertz detector corresponding to the ith row of pixel points, and an ith calibration parameter is determined by using the voltage value corresponding to the jth pixel point, a calibration reference value of the ith row of pixel points, and a coefficient ki, where the ith calibration parameter satisfies the following formula of △ Ti ═ ki × (U × (where U is a ratio of ki) to kiHi-ULij) Wherein the △ Ti represents the ith calibration parameter, the UHiDenotes the ith calibration reference value, ULikAnd representing the voltage value of the jth pixel point in the ith row of pixel points, and calibrating the pixel value of the jth pixel point according to the ith calibration parameter.
In a possible design, the above apparatus further includes:
a test module, configured to obtain sample data before the calibration module determines an ith calibration parameter by using a voltage value corresponding to the jth pixel point, a calibration reference value of the ith column of pixel points, and a coefficient ki, where the sample data includes Y pairs of data, each pair of data in the Y pairs of data includes a temperature and a voltage value corresponding to the temperature, the temperature is a temperature of the ith terahertz detector radiating the black body radiation source, and the voltage value is a voltage value obtained by the ith terahertz detector radiating the black body radiation source after an initial voltage is amplified; determining a relation curve of the input temperature and the output voltage of the ith terahertz detector according to the Y pair of data to obtain ki, wherein the relation curve meets the following formula: t ═ Ai + kiU, where Ai denotes the intercept.
In a feasible design, the Y pair of data includes a temperature k and a voltage value m corresponding to the temperature k, where the voltage value m corresponding to the temperature k is an average value of amplified voltage values of a plurality of initial voltages obtained by the i-th terahertz detector radiating the black body radiation source when the temperature of the black body radiation source is the temperature k.
In a possible design, the above apparatus further includes:
the warning module is used for judging whether the object to be detected carries a control tool or not according to the second terahertz image after the display module displays the second terahertz image; and when the object to be detected carries the control tool, outputting alarm information.
In a third aspect, an embodiment of the present invention provides an electronic device, which includes a processor, a memory, and a computer program stored in the memory and executable on the processor, and the processor executes the computer program to implement the method according to the first aspect or the various possible implementations of the first aspect.
In a fourth aspect, embodiments of the present invention provide a readable storage medium, which stores instructions that, when executed on an electronic device, cause the electronic device to perform the method according to the first aspect or the various possible implementations of the first aspect.
In a fifth aspect, embodiments of the present invention provide a computer program product, which, when run on an electronic device, causes the electronic device to perform the method according to the first aspect or the various possible implementations of the first aspect.
According to the security inspection method and device provided by the embodiment of the invention, the electronic equipment scans the object to be detected by using the terahertz array detector to obtain the first terahertz image. Then, for each column of pixel points in the first terahertz image, calibration reference values of corresponding columns are respectively determined. And then, according to the calibration reference value, calibrating the pixel points in the corresponding row in the first terahertz image to obtain a second terahertz image, and displaying the second terahertz image. By adopting the scheme, the terahertz image with good quality is obtained by calibrating the terahertz image with poor quality, and the purpose of improving the accuracy of security inspection is realized by performing security inspection according to the terahertz image with good quality.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a schematic diagram of a test system for acquiring sample data in a security inspection method according to an embodiment of the present disclosure;
FIG. 2 is a graph showing a relationship between an input temperature and an output voltage of a terahertz detector in the security inspection method provided by the embodiment of the application;
fig. 3 is a flowchart of a security inspection method provided in an embodiment of the present application;
fig. 4 is a schematic diagram of a first terahertz image in a security inspection method provided by an embodiment of the present application;
fig. 5 is a schematic structural diagram of a security inspection apparatus according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of another security inspection apparatus according to an embodiment of the present invention;
fig. 7 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
At present, if a high-sensitivity area array terahertz detector is constructed by utilizing a terahertz detector, the manufacturing cost is high. Therefore, a linear array terahertz detector is usually constructed by using a terahertz detector, the linear array terahertz detector is formed by arranging a plurality of detectors on a straight line, the linear array terahertz detector cannot adopt focal plane imaging, and scanning imaging is mostly adopted. In the non-contact, large-view-field, rapid and high-resolution human body terahertz scanning imaging in public places such as airports and stations, the terahertz optical machine scanning imaging adopting a plurality of terahertz detectors is the most practical human body terahertz security inspection imaging method. The plurality of terahertz detectors form a linear array terahertz detector, and the linear array terahertz detector can also be called a terahertz array detector.
When the terahertz array detector optical machine is used for scanning and imaging, each terahertz detector in the terahertz array detector is influenced by the characteristics of the terahertz detector, and under the condition that input signals are the same, output signals of different terahertz detectors are different, so that the quality of a terahertz image acquired by the terahertz array detector is poor. Moreover, due to the noise baseline drift of the terahertz array detector after long-time operation, the output signals of different terahertz detectors are different under the condition that the input signals are the same.
In view of this, the embodiment of the present application provides a security inspection method and apparatus, which calibrate a terahertz image with poor quality to obtain a terahertz image with good quality, and perform security inspection according to the terahertz image with good quality, so as to achieve the purpose of improving the accuracy of security inspection.
The security inspection method provided by the embodiment of the application can be applied to electronic equipment. In a specific application, the electronic device may be a device integrating the terahertz array detector, such as a security inspection device, or a device capable of communicating with the terahertz array detector, such as a server, a personal computer, or the like. The embodiments of the present application will be described in detail below by taking an electronic device as an example of a device integrating a terahertz array detector.
In the embodiment of the application, the terahertz array detector is a linear array terahertz detector, such as a 64 linear array terahertz detector, and 64 terahertz detectors of the 64 linear array terahertz detector are linearly arranged. In the security inspection process, an original first terahertz image obtained by scanning an object to be detected by a terahertz array detector needs to be calibrated to obtain a second terahertz image, and then whether the object to be detected carries control tools such as guns and cutters is judged by using the second terahertz image. The calibration of the first terahertz image refers to the calibration of the pixel value of each pixel point in the first terahertz image. Before calibration, a relation curve of the input temperature and the output voltage of each terahertz detector in the terahertz array detector needs to be obtained, and the stage is called a test stage. And then, calibrating the pixel points scanned by each terahertz detector by using the corresponding relation curve, wherein the calibration stage is called as a calibration stage. These two stages will be described in detail below.
First, a testing phase.
In the embodiment of the application, the terahertz array detector comprises X terahertz detectors, the X terahertz detectors are arranged in a linear array, X is larger than or equal to 1, and the purpose of the test stage is to obtain a relationship curve between the input temperature and the output voltage of each terahertz detector in the X terahertz detectors, for example, if 64 terahertz detectors are provided in a 64-linear array terahertz detector, 64 relationship curves need to be obtained.
In the process of obtaining the relation curve, for each terahertz detector of the terahertz array detector, the electronic device obtains sample data. Taking an ith terahertz detector as an example, sample data acquired by electronic equipment includes Y pairs of data, each pair of data in the Y pairs of data includes a temperature and a voltage value corresponding to the temperature, the temperature is a temperature of a black body radiation source radiated by the ith terahertz detector, and the voltage value is a voltage value obtained by amplifying an initial voltage obtained by the radiation of the black body radiation source by the ith terahertz detector. Then, the electronic device determines a relation curve of the input temperature and the output voltage of the ith terahertz detector according to the Y pair of data, wherein the relation curve meets the following formula: t ═ Ai + kiU, where Ai denotes the intercept and ki denotes the coefficient. For example, see fig. 1.
Fig. 1 is a schematic diagram of a test system for acquiring sample data in a security inspection method according to an embodiment of the present disclosure. Referring to fig. 1, the test system includes a blackbody radiation source 1, a terahertz detector 2, a preamplifier 3, and a data acquisition card. The blackbody radiation source 1 is placed on a stable test platform, the terahertz detector 2 is placed in front of a radiation window of the blackbody radiation source 1, a signal output port of the terahertz detector 2 is connected with the preamplifier 3, and a data output port of the preamplifier 3 is connected with the data acquisition card 4 and used for acquiring an output signal of the preamplifier 3. It should be noted that, although only one terahertz detector 2 is illustrated in fig. 1, in practice, a relationship curve needs to be fitted to each terahertz detector 2, each terahertz detector 2 has one preamplifier 3 corresponding to it, and the data output port of each preamplifier 3 is connected to the data acquisition card 4. Because the radiation range of the black body radiation source 1 is limited, the number of the radiation terahertz detectors 2 which can be radiated at each time is limited, and therefore batch measurement can be carried out to obtain the relation curve of each terahertz detector in the X terahertz detectors.
Referring to fig. 1, when the temperature of the blackbody radiation source 1 is set to T1, the terahertz wave radiated by the blackbody radiation source 1 is detected by the terahertz detector 2, and then a voltage signal is output, the voltage signal is amplified by the preamplifier 3, and the amplified signal is collected by the data acquisition card 4. The data acquisition card 4 may acquire N voltage values, and average the N voltage values to obtain an average value, thereby obtaining a voltage value U1 corresponding to T1.
The temperature provided for the blackbody radiation source 1 is modified to be T2, the terahertz wave radiated by the blackbody radiation source 1 is detected by the terahertz detector 2, a voltage signal is output, the voltage signal is amplified by the preamplifier 3, and the amplified signal is collected by the data acquisition card 4. The data acquisition card 4 may acquire N voltage values, and average the N voltage values to obtain an average value, thereby obtaining a voltage value U2 corresponding to T2.
The temperature provided for the blackbody radiation source 1 is modified to be T3, the terahertz wave radiated by the blackbody radiation source 1 is detected by the terahertz detector 2, a voltage signal is output, the voltage signal is amplified by the preamplifier 3, and the amplified signal is collected by the data acquisition card 4. The data acquisition card 4 may acquire N voltage values, and average the N voltage values to obtain an average value, thereby obtaining a voltage value U3 corresponding to T3.
According to the operation, the analogy is carried out in sequence, so that Y pairs of data are obtained, the temperature k contained in the Y pairs of data and the voltage value m corresponding to the temperature k are obtained, and the voltage value m corresponding to the temperature k is the average value of the amplified voltage values of a plurality of initial voltages obtained by the black body radiation source through radiation of the ith terahertz detector when the temperature of the black body radiation source is the temperature k. And then determining the relation curve of the input temperature and the output voltage of the terahertz detector based on the Y pair of data. For example, see fig. 2.
Fig. 2 is a graph of a relationship between an input temperature and an output voltage of a terahertz detector in the security inspection method provided by the embodiment of the application. Referring to fig. 2, the temperature k in the Y group of data is taken as an abscissa, and the voltage value m acquired by the data card is taken as an ordinate, so as to fit a relationship curve between the input temperature and the output voltage of the terahertz detector. In fig. 2, the coordinate of each point from point P1 to point P5 is temperature k, the ordinate is voltage m, and the straight line in the graph shows the fitted relationship: T-Ai + kiU.
Wherein, T represents the temperature of the blackbody radiation source 1, the temperature of the blackbody radiation source 1 is in direct proportion to the power of the terahertz wave of the blackbody radiation source 1, Ai represents the intercept of the relation curve, k1 represents the slope of the curve, namely the coefficient, U represents the average value of N times of measurement, and N is more than or equal to 1.
According to the above, it can be seen that: for each terahertz detector, namely the ith terahertz detector, the relationship curve of the input temperature and the output voltage of the terahertz detector can be obtained in the manner, the process of determining the relationship curve is substantially the process of determining Ai and ki, Ai of the relationship curves of different terahertz detectors may be the same or different, and in the same way, ki of the relationship curves of different terahertz detectors may be the same or different.
Second, a calibration phase.
Fig. 3 is a flowchart of a security inspection method provided in an embodiment of the present application, where the embodiment is described from the perspective of an electronic device, and the embodiment includes:
101. and scanning the object to be detected by using a terahertz array detector to obtain a first terahertz image.
The object to be detected can be a human body and the like. Taking the scanning direction as scanning from top to bottom as an example, because the terahertz array detector limits the terahertz detector, in the vertical scanning process, one line of pixel points is obtained in each scanning, after each scanning, the terahertz array detector moves downwards, and the scanning is continued to obtain one line of pixel points … … until the first terahertz image is obtained. For example, see fig. 4.
Fig. 4 is a schematic diagram of a first terahertz image in the security inspection method provided by the embodiment of the application. Referring to fig. 4, when the number of the terahertz detectors is X, a line of pixel points scanned each time includes X pixel points, and each column of pixel points is obtained by scanning the object to be detected by the same terahertz detector. Only one row and one column of pixels are shown.
102. And respectively determining a calibration reference value of a corresponding column for each column of pixel points in the first terahertz image.
As can be seen from fig. 1 and 2 above: the output signal of each terahertz detector is a voltage value, that is to say, each pixel corresponds to a voltage value. For each type of pixel point, voltage values corresponding to different pixel points may be different, and in order to calibrate the pixel value of the pixel point, a calibration reference value needs to be determined. For example, for the ith row of pixel points, the voltage value of the first pixel point in the row of pixel points is used as the calibration reference value of the ith row of pixel points; for another example, the voltage value corresponding to each pixel point in the preset number of pixel points in the ith row of pixel points is determined to obtain the preset number of voltage values, the average voltage value of the preset number of voltage values is used as the calibration reference value of the ith row of pixel points, and the ith row of pixel pointsIs any one of the X rows of pixel points. Assume a calibration reference value of UHiThen, according to the relationship curve, the following can be obtained: t isH＝Ai+kiUHiSince Ai and ki are known, T can be obtainedHi。
103. And calibrating the pixel points in the corresponding row in the first terahertz image according to the calibration reference value to obtain a second terahertz image.
Taking the ith row of pixel points as an example, assume that the voltage value corresponding to the jth pixel point in the row of pixel points is ULijThen, according to the relationship curve, the following can be obtained: t isLij＝Ai+ki ULijSince Ai and ki are known, T can be obtainedLij. Then, utilizing the voltage value U corresponding to the jth pixel pointLijAnd the calibration reference value U of the ith row of pixel pointsHiAnd a coefficient ki, determining an ith calibration parameter satisfying the following formula △ Ti ki x (U)Hij-ULij) Wherein, the △ Ti represents the ith calibration parameter of the ith column of pixel points, and the UHiDenotes the ith calibration reference value, ULijAnd finally, calibrating the pixel value of the jth pixel point according to the ith calibration parameter, namely calibrating the pixel value of the jth pixel point by the electronic equipment according to △ Ti.
104. And displaying the second terahertz image.
Illustratively, the electronic device displays the second terahertz image including the contour and the like of the object to be detected through a display screen and the like. If other contours, such as contours of control tools such as a knife, a gun and the like, are also displayed on the second terahertz image, it is indicated that the object to be detected cannot pass through security inspection.
In addition, if the electronic equipment finds and analyzes the second terahertz image to obtain that the object to be detected may carry guns, cutters and the like, alarm information is output. For example, a security check worker is prompted by voice, or a prompt message or the like is displayed on a display screen.
According to the case method provided by the embodiment of the application, the electronic equipment scans the object to be detected by using the terahertz array detector to obtain the first terahertz image. Then, for each column of pixel points in the first terahertz image, calibration reference values of corresponding columns are respectively determined. And then, according to the calibration reference value, calibrating the pixel points in the corresponding row in the first terahertz image to obtain a second terahertz image, and displaying the second terahertz image. By adopting the scheme, the terahertz image with good quality is obtained by calibrating the terahertz image with poor quality, and the purpose of improving the accuracy of security inspection is realized by performing security inspection according to the terahertz image with good quality.
The following are embodiments of the apparatus of the present invention that may be used to perform embodiments of the method of the present invention. For details which are not disclosed in the embodiments of the apparatus of the present invention, reference is made to the embodiments of the method of the present invention.
Fig. 5 is a schematic structural diagram of a security inspection apparatus according to an embodiment of the present invention. The security check device 100 may be implemented by software and/or hardware. As shown in fig. 5, the security inspection apparatus 100 includes:
the scanning module 11 is configured to scan an object to be detected by using a terahertz array detector to obtain a first terahertz image;
the determining module 12 is configured to determine, for each column of pixel points in the first terahertz image, calibration reference values of corresponding columns respectively;
the calibration module 13 is configured to calibrate pixel points in a corresponding row in the first terahertz image according to the calibration reference value to obtain a second terahertz image;
and the display module 14 is used for displaying the second terahertz image.
In a feasible design, the terahertz array detector comprises X terahertz detectors, the X terahertz detectors are arranged in a linear array, X is greater than or equal to 1, the first terahertz image comprises X rows of pixel points, different terahertz detectors correspond to different rows of pixel points in the X rows of pixel points, the determining module 12 is configured to determine a voltage value corresponding to each pixel point in a preset number of pixel points in an ith row of pixel points, obtain a preset number of voltage values, use an average voltage value of the preset number of voltage values as a calibration reference value of the ith row of pixel points, and the ith row of pixel points is any row of the X rows of pixel points.
In a feasible design, the calibration module 13 is configured to determine, for a jth pixel point in the ith row of pixel points, a voltage value corresponding to the jth pixel point, where the voltage value is a voltage value obtained by an ith terahertz detector radiating the object to be detected after amplifying an initial voltage, the ith terahertz detector is a terahertz detector corresponding to the ith row of pixel points, and determine an ith calibration parameter by using the voltage value corresponding to the jth pixel point, a calibration reference value of the ith row of pixel points, and a coefficient ki, where the ith calibration parameter satisfies a formula of △ Ti ═ ki × (U × (where U is a ratio of ki to ki)Hi-ULij) Wherein the △ Ti represents the ith calibration parameter, the UHiDenotes the ith calibration reference value, ULikAnd representing the voltage value of the jth pixel point in the ith row of pixel points, and calibrating the pixel value of the jth pixel point according to the ith calibration parameter.
Fig. 6 is a schematic structural diagram of another security inspection apparatus according to an embodiment of the present invention. The security inspection apparatus 100 provided in this embodiment further includes, on the basis of fig. 5:
a test module 15, configured to obtain sample data before the calibration module 13 determines an ith calibration parameter by using a voltage value corresponding to the jth pixel point, a calibration reference value of the ith column of pixel points, and a coefficient ki, where the sample data includes Y pairs of data, each pair of data in the Y pairs of data includes a temperature and a voltage value corresponding to the temperature, the temperature is a temperature of the ith terahertz detector radiating the black body radiation source, and the voltage value is a voltage value obtained by the ith terahertz detector radiating the black body radiation source after an initial voltage is amplified; determining a relation curve of the input temperature and the output voltage of the ith terahertz detector according to the Y pair of data to obtain ki, wherein the relation curve meets the following formula: t ═ Ai + kiU, where Ai denotes the intercept.
In a feasible implementation manner, the temperature k included in the pair of data Y and the voltage value m corresponding to the temperature k are average values of a plurality of amplified initial voltages obtained by the i-th terahertz detector radiating the black body radiation source when the temperature of the black body radiation source is the temperature k.
Referring to fig. 6 again, in a possible design, the apparatus further includes:
the warning module 16 is configured to, after the calibration module 13 calibrates the pixel points in the corresponding column in the first terahertz image according to the calibration reference value, determine whether the object to be detected carries a control tool according to the second terahertz image; and when the object to be detected carries the control tool, outputting alarm information.
Fig. 7 is a schematic structural diagram of an electronic device according to an embodiment of the present invention. As shown in fig. 6, the electronic apparatus 200 includes:
at least one processor 21 and memory 22;
the memory 22 stores computer-executable instructions;
the at least one processor 21 executes computer-executable instructions stored by the memory 22, causing the at least one processor 21 to perform the security check method as described above.
Optionally, the electronic device 200 further comprises a communication component 23. The processor 21, the memory 22, and the communication unit 23 may be connected by a bus 24.
The embodiment of the invention also provides a readable storage medium, wherein the readable storage medium stores computer execution instructions, and the computer execution instructions are used for realizing the security inspection method when being executed by a processor.
The embodiment of the invention also provides a computer program product, which enables the electronic equipment to execute the security check method when the computer program product runs on the electronic equipment.
Those of ordinary skill in the art will understand that: all or a portion of the steps of implementing the above-described method embodiments may be performed by hardware associated with program instructions. The program may be stored in a computer-readable storage medium. When executed, the program performs steps comprising the method embodiments described above; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A security inspection method, comprising:
scanning an object to be detected by using a terahertz array detector to obtain a first terahertz image;
for each column of pixel points in the first terahertz image, respectively determining a calibration reference value of a corresponding column;
calibrating pixel points in a corresponding row in the first terahertz image according to the calibration reference value to obtain a second terahertz image;
and displaying the second terahertz image.
2. The method according to claim 1, wherein the terahertz array detector comprises X terahertz detectors, the X terahertz detectors are arranged in a linear array, X is greater than or equal to 1, the first terahertz image comprises X columns of pixel points, different terahertz detectors correspond to different columns of pixel points in the X columns of pixel points, and for each column of pixel points in the first terahertz image, a calibration reference value of the corresponding column is respectively determined, including:
determining a voltage value corresponding to each pixel point in a preset number of pixel points in an ith row of pixel points to obtain a preset number of voltage values, and taking an average voltage value of the preset number of voltage values as a calibration reference value of the ith row of pixel points, wherein the ith row of pixel points is any one row in the X rows of pixel points.
3. The method according to claim 2, wherein the calibrating, according to the calibration reference value, pixel points in a corresponding column in the first terahertz image to obtain a second terahertz image comprises:
for a jth pixel point in the ith row of pixel points, determining a voltage value corresponding to the jth pixel point, wherein the voltage value is obtained by amplifying an initial voltage obtained by radiating the object to be detected by an ith terahertz detector, and the ith terahertz detector is a terahertz detector corresponding to the ith row of pixel points;
determining an ith calibration parameter by using the voltage value corresponding to the jth pixel point, the calibration reference value of the ith row of pixel points and a coefficient ki, wherein the ith calibration parameter satisfies the following formula:
△Ti＝ki×(UHi-ULij) Wherein the △ Ti represents the ith calibration parameter, the UHiDenotes the ith calibration reference value, ULikRepresenting the voltage value of the jth pixel point in the ith row of pixel points;
and calibrating the pixel value of the j pixel point according to the i calibration parameter.
4. The method according to claim 3, wherein before determining the ith calibration parameter by using the voltage value corresponding to the jth pixel point, the calibration reference value for the ith column of pixel points, and the coefficient ki, the method further comprises:
acquiring sample data, wherein the sample data comprises Y pairs of data, each pair of data in the Y pairs of data comprises a temperature and a voltage value corresponding to the temperature, the temperature is the temperature of an ith terahertz detector radiating a black body radiation source, and the voltage value is an amplified voltage value of an initial voltage obtained by the ith terahertz detector radiating the black body radiation source;
determining a relation curve of the input temperature and the output voltage of the ith terahertz detector according to the Y pair of data to obtain ki, wherein the relation curve meets the following formula: t ═ Ai + kiU, where Ai denotes the intercept.
5. The method according to claim 4, wherein the Y pair of data comprises a temperature k and a voltage value m corresponding to the temperature k, and the voltage value m corresponding to the temperature k is an average value of amplified voltage values of a plurality of initial voltages obtained by the i-th terahertz detector radiating the blackbody radiation source when the temperature of the blackbody radiation source is the temperature k.
6. The method according to any one of claims 1 to 5, wherein after the displaying the second terahertz image, the method further comprises:
judging whether the object to be detected carries a control tool or not according to the second terahertz image;
and when the object to be detected carries the control tool, outputting alarm information.
7. A security device, comprising:
the scanning module is used for scanning an object to be detected by utilizing the terahertz array detector to obtain a first terahertz image;
the determining module is used for respectively determining a calibration reference value of each corresponding column of pixel points in the first terahertz image;
the calibration module is used for calibrating pixel points in a corresponding row in the first terahertz image according to the calibration reference value to obtain a second terahertz image;
and the display module is used for displaying the second terahertz image.
8. The device according to claim 7, wherein the terahertz array detector comprises X terahertz detectors, the X terahertz detectors are arranged in a linear array, X is larger than or equal to 1, the first terahertz image comprises X rows of pixel points, different terahertz detectors correspond to different rows of pixel points in the X rows of pixel points, the determining module is used for determining a voltage value corresponding to each pixel point in a preset number of pixel points in an ith row of pixel points to obtain a preset number of voltage values, an average voltage value of the preset number of voltage values is used as a calibration reference value of the ith row of pixel points, and the ith row of pixel points is any one of the X rows of pixel points.
9. An electronic device, comprising: a processor, a memory, and a computer program; wherein the computer program is stored in the memory and configured to be executed by the processor, the computer program comprising instructions for performing the method of any of claims 1-6.
10. A readable storage medium having stored therein instructions, which when run on an electronic device, cause the electronic device to perform the method of any one of claims 1-6.
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