CN113670445A - Calibration method for imaging heterogeneity of thermal infrared imager - Google Patents

Calibration method for imaging heterogeneity of thermal infrared imager Download PDF

Info

Publication number
CN113670445A
CN113670445A CN202110875174.2A CN202110875174A CN113670445A CN 113670445 A CN113670445 A CN 113670445A CN 202110875174 A CN202110875174 A CN 202110875174A CN 113670445 A CN113670445 A CN 113670445A
Authority
CN
China
Prior art keywords
temperature
infrared imager
thermal infrared
square
thermal
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.)
Granted
Application number
CN202110875174.2A
Other languages
Chinese (zh)
Other versions
CN113670445B (en
Inventor
舒双宝
王子艺
梁华俊
张育中
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.)
Hefei University of Technology
Original Assignee
Hefei University of Technology
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 Hefei University of Technology filed Critical Hefei University of Technology
Priority to CN202110875174.2A priority Critical patent/CN113670445B/en
Publication of CN113670445A publication Critical patent/CN113670445A/en
Application granted granted Critical
Publication of CN113670445B publication Critical patent/CN113670445B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry

Abstract

The invention relates to the technical field of thermal infrared imager calibration, in particular to a method for calibrating imaging heterogeneity of a thermal infrared imager, which comprises the following steps: (1) dividing a calibration temperature section according to the dynamic range of the thermal infrared imager; (2) dividing a calibration area according to the resolution of the thermal infrared imager; (3) measuring the temperature of the black body furnace in each calibration area of the infrared thermal image in each temperature section; (4) acquiring a calibration coefficient of each pixel point of the thermal infrared imager in the whole temperature measurement range; (5) calculating the corrected target temperature according to the calibration coefficient; the invention solves the problem of measurement result errors caused by lens distortion and imaging nonuniformity of a photosensitive element when the thermal infrared imager measures temperature in a large view field; specifically, the dynamic range of the thermal infrared imager is segmented and calibrated, so that errors caused by the nonlinear characteristic of the temperature response of a photoelectric conversion device in the thermal infrared imager are reduced, and the temperature measurement precision of the thermal infrared imager is improved.

Description

Calibration method for imaging heterogeneity of thermal infrared imager
Technical Field
The invention relates to the technical field of thermal infrared imager calibration, in particular to a method for calibrating imaging heterogeneity of a thermal infrared imager.
Background
A thermal infrared imager is a device that images an object by measuring the infrared radiation emitted by the object. Infrared radiation is an electromagnetic wave with a wavelength longer than visible light. Since any object with a temperature higher than absolute zero (-273.15 ℃), infrared energy is radiated outwards, and according to the Planck's radiation law, the temperature of the object can be calculated by knowing the intensity of infrared radiation emitted by the object in a certain wave band. Therefore, a lot of information which can not be obtained through visible light can be obtained through the thermal infrared imager, so that the thermal infrared imager has wide application in the fields of military affairs, manufacturing industry, medicine and the like.
In a plurality of application scenes of the thermal infrared imager, the thermal infrared imager is mostly used for carrying out non-contact temperature measurement. In a battlefield, some military targets can reduce observability after passing through camouflage and even can be integrated with the surrounding environment, so that the military targets cannot be distinguished by naked eyes. But the target has different infrared characteristics from the surrounding environment, and the target can be easily distinguished from the environment by using the thermal infrared imager. In large industrial scenes such as power plants, substations and the like, abnormalities of some devices may not be discovered by naked eyes for the first time, but temperature changes caused by the abnormalities can be detected by a thermal infrared imager in real time. In addition, there is an increasing demand for body temperature monitoring in places with large human traffic, such as airports and stations, and more infrared thermometers have been developed to achieve both the efficiency of personnel passage and real-time body temperature monitoring.
When the thermal infrared imager is used for measuring temperature, accurate temperature data are obtained, which is a precondition for ensuring safe production activities. However, for the current thermal infrared imager, the distortion of the lens is a common problem. The distortion of the lens mainly comes from the physical performance of the lens and processing and assembling errors, and the distortion of the lens can cause temperature deviation in an image measured by a thermal infrared imager. Taking barrel distortion as an example, the final image will have barrel-expansion distortion. The center position of the imaging picture has almost no distortion, and the temperature measurement result is basically accurate. The farther from the center of the screen, the larger the distortion and hence the more severe the temperature drift. This results in different measurements at various locations on the thermostatic target in the same frame of image. In addition, the thermal infrared imager measures temperature by detecting infrared radiation of a target object, converting the infrared radiation into an electric signal by using an infrared detector sensitive to the infrared radiation, and displaying a temperature image of the target through a series of circuits. For some thermal infrared imagers with larger dynamic ranges, the response of the infrared detector to different temperatures may not be linear. For example, the response is stronger in the high temperature range and weaker in the low temperature range. Furthermore, as the time of use increases, the response characteristics of the detector may change, and factory calibration may become ineffective. In view of the above problems of the thermal infrared imagers, it is necessary to develop a simple and easy calibration method for imaging non-uniformity of the thermal infrared imagers.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provides a method for calibrating imaging heterogeneity of a thermal infrared imager.
In order to achieve the above object, the present invention provides a method for calibrating imaging non-uniformity of a thermal infrared imager, comprising the following steps:
(1) dividing a calibration temperature section according to the dynamic range of the thermal infrared imager;
(2) dividing a calibration area according to the resolution of the thermal infrared imager;
(3) measuring the temperature of the black body furnace in each calibration area of the infrared thermal image in each temperature section;
(4) acquiring a calibration coefficient of each pixel point of the thermal infrared imager in the whole temperature measurement range;
(5) and calculating the corrected target temperature according to the calibration coefficient.
In a further technical scheme, in the step (1), the dynamic range of the thermal infrared imager is uniformly divided into continuous calibration temperature sections according to a certain gradient, and the highest temperature and the lowest temperature of each calibration temperature section are respectively TmaxAnd Tmin。
In a further technical scheme, the step (2) specifically comprises the following steps:
(2.1) dividing the thermal image of the thermal infrared imager into mutually connected calibration areas in a grid shape according to the resolution of the thermal infrared imager detector;
(2.2) setting the calibration area at the upper left corner as a No. 1 square, numbering the other calibration areas sequentially from left to right and from top to bottom, namely numbering from left to right, and continuing numbering from left to right from the next line after the line is numbered.
In a further technical scheme, the step (3) specifically comprises the following steps:
(3.1) mounting the thermal infrared imager on a base, wherein the base is mounted on a horizontal sliding rail, and the horizontal sliding rail can integrally move on a sliding rail in the vertical direction; therefore, the thermal infrared imager can move in the horizontal and vertical directions, and meanwhile, the distance between the thermal infrared imager and the black body furnace in the direction vertical to the focal plane of the camera can be ensured not to change;
(3.2) selecting the temperature section to be calibrated and determining good TmaxAnd TminTwo temperature values T are selected1And T2To satisfy Tmin＜T1＜T2＜TmaxSetting the temperature of the black body furnace to T1；
(3.3) adjusting the horizontal and vertical positions of the thermal infrared imager without changing the position of the black body furnace, adjusting the position of the black body furnace in a preview picture of the thermal infrared imager to be a No. 1 square, and completely filling the No. 1 square;
(3.4) recording the thermal image of the thermal infrared imager, reading the temperature value of each pixel point of the No. 1 square in the thermal image, and acquiring a No. 1 square two-dimensional temperature data matrix1Tm1And has:
Figure BDA0003190062060000031
wherein the left subscript 1 of each item represents square No. 1 of the thermal image obtained by the measurement;
1Tm1(i, j) represents the measured value corresponding to the pixel point of the ith row and the jth column in the No. 1 square;
T1(i, j) represents the temperature value of the measured object, namely the blackbody furnace, corresponding to the pixel point of the ith row and jth column in the block No. 1 of the measured thermal image, and T is1(i,j)＝T1；
Figure BDA0003190062060000032
Indicating the temperature interval Tmin～TmaxAttenuation coefficients of all pixel points of the inner No. 1 square;
Figure BDA0003190062060000033
indicating the temperature interval Tmin～TmaxDrift coefficients of all pixel points of the inner No. 1 square;
(3.5) moving the position of the thermal infrared imager through a horizontal sliding rail, adjusting the position of the black body furnace in a preview picture of the thermal infrared imager to be in the No. 2 square block, and completely covering the No. 2 square block;
(3.6) recording the thermal image of the thermal infrared imager, reading the temperature value of each pixel point of the No. 2 square in the thermal image, and acquiring a No. 2 square two-dimensional temperature data matrix2Tm1And has:
Figure BDA0003190062060000034
wherein the left subscript 2 of each item represents square No. 2 of the thermal image obtained by the measurement;
2Tm1(i, j) represents the measured value corresponding to the pixel point in the ith row and the jth column in the No. 2 square;
T1(i, j) represents the temperature value of the measured object, i.e. the blackbody furnace, corresponding to the pixel point in the ith row and jth column in the block No. 2 of the thermal image obtained by measurement, and has T1(i,j)＝T1；
Figure BDA0003190062060000035
Indicating the temperature interval Tmin～TmaxAttenuation coefficients of all pixel points of the inner No. 2 square;
Figure BDA0003190062060000036
indicating the temperature interval Tmin～TmaxDrift coefficients of all pixel points of the inner No. 2 square;
(3.7) moving the position of the thermal infrared imager through the horizontal and vertical sliding rails, sequentially adjusting the position of the black body furnace in the preview picture of the thermal infrared imager to the rest blocks, completely covering each block, recording thermal images, and sequentially obtaining a relational expression between a two-dimensional temperature data matrix of each block and the temperature of the black body furnace;
(3.8) setting the Black body furnace temperature to T2Moving the thermal infrared imager, adjusting the position of the black body furnace in the preview picture of the thermal infrared imager to be a No. 1 square, and completely filling the No. 1 square;
(3.9) recording the thermal image of the thermal infrared imager, reading the temperature value of each pixel point of the No. 1 square in the thermal image, and acquiring a No. 1 square two-dimensional temperature data matrix1Tm2And has:
Figure BDA0003190062060000041
wherein the left subscript 1 of each item represents square No. 1 of the thermal image obtained by the measurement;
1Tm2(i, j) represents the measured value corresponding to the pixel point of the ith row and the jth column in the No. 1 square;
T2(i, j) represents the temperature value of the measured object, namely the blackbody furnace, corresponding to the pixel point of the ith row and jth column in the block No. 1 of the measured thermal image, and T is2(i,j)＝T2；
Figure BDA0003190062060000042
Indicating the temperature interval Tmin～TmaxAttenuation coefficients of all pixel points of the inner No. 1 square;
Figure BDA0003190062060000043
indicating the temperature interval Tmin～TmaxDrift of each pixel point of inner No. 1 squareA coefficient;
and (3.10) moving the thermal infrared imagers through the horizontal sliding rail and the vertical sliding rail, respectively adjusting the positions of the black body furnace in the preview picture of the thermal infrared imager into the rest blocks in sequence, completely covering each block, repeating the step (3.9), recording the thermal images, and sequentially obtaining the relational expression between the two-dimensional temperature data matrix of each block and the temperature of the black body furnace.
In a further technical scheme, the step (4) specifically comprises the following steps:
(4.1) for block number 1 in step (2.2), the following equation set:
Figure BDA0003190062060000044
Figure BDA0003190062060000045
attenuation coefficient matrix of block 1
Figure BDA0003190062060000046
And a matrix of drift coefficients
Figure BDA0003190062060000047
This can be obtained by the following equations (6) and (7):
Figure BDA0003190062060000048
Figure BDA0003190062060000049
(4.2) sequentially calculating the temperature sections T of all squares according to the method in (4.1)min～TmaxAttenuation coefficient matrix of
Figure BDA00031900620600000410
And a matrix of drift coefficients
Figure BDA00031900620600000411
In a further embodiment, in step (5), for the point with coordinate (x, y) in the n-th square, the measured value in the thermal image is TmeasureIf the measured target true temperature corresponding to the point is T, the calculation formula is shown as the formula (8):
Figure BDA0003190062060000051
compared with the prior art, the invention solves the problem of measurement result errors caused by lens distortion and imaging nonuniformity of the photosensitive element when the thermal infrared imager measures temperature in a large view field; specifically, the dynamic range of the thermal infrared imager is segmented and calibrated, so that errors caused by the nonlinear characteristic of the temperature response of a photoelectric conversion device in the thermal infrared imager are reduced, and the temperature measurement precision of the thermal infrared imager is improved.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Drawings
FIG. 1 is a schematic view of a two-dimensional sliding platform for fixing a thermal infrared imager and driving the thermal infrared imager to move in horizontal and vertical directions according to the present invention;
FIG. 2 is a schematic diagram illustrating the division of thermal images of a thermal infrared imager into calibration blocks according to the present invention;
FIG. 3 is a schematic diagram showing a calibration area and a position of a blackbody furnace in a thermal image of a thermal infrared imager according to the present invention;
FIG. 4 is a schematic diagram of a black-body furnace completely covering an AR01 square in a thermal infrared imager preview screen in embodiment 1 of the present invention;
FIG. 5 is a schematic diagram of a black-body furnace completely covering an AR02 square in a thermal infrared imager preview screen in embodiment 1 of the present invention;
the reference numbers in the figures illustrate: 1-base, 2-horizontal slide rail, 3-vertical slide rail.
Detailed Description
In order to make the technical means, the creation features, the achievement purposes and the effects of the invention easy to understand, the invention is further clarified with the specific embodiments.
Example 1
The embodiment provides a method for calibrating imaging heterogeneity of a thermal infrared imager, which specifically comprises the following steps:
s1: the thermal infrared imager model that this embodiment used is FLIR A40M, as shown in FIG. 1, installs the thermal infrared imager on a base 1, and the industrial computer controls the motor rotation of base below for the base can remove about on horizontal slide rail 2, and the industrial computer can also control horizontal slide rail and the whole reciprocating motion of base through the motor control in the vertical slide rail 3 simultaneously. The thermal infrared imager is connected with the industrial personal computer through a data line, and the emissivity is set to be 1 in control software of the industrial personal computer.
S2: and (3) enabling the lens of the thermal infrared imager to be opposite to the black body furnace, wherein the distance between the lens of the thermal infrared imager and the black body furnace is 50 cm. In the experimental process, the positions of the tripod and the blackbody furnace are fixed and unchanged, and the room temperature is kept at 20 ℃.
S3: according to the temperature measuring range of the FLIR A40M thermal infrared imager and the performance parameters of the black body furnace, dividing the calibration temperature section into 0-100 ℃, 100-200 ℃, 200-300 ℃, 300-400 ℃ and 400-500 ℃.
S4: the resolution of the FLIR A40M thermal infrared imager was 320X 240. As shown in fig. 4, the preview screen of the thermal imager is opened in the thermal infrared imager control software, and the preview screen is divided into 12 80 × 80 rectangular blocks by using a rectangular marking tool carried by the software. The numbers of the squares from the upper left corner are AR01, AR2, and AR 12.
S5: firstly, calibrating a temperature range of 0-100 ℃. When the temperature of the black body furnace is set to T1And (4) continuing to wait for 20 minutes after the reading of the black body furnace reaches the set value so that the temperature of the black body furnace is stabilized.
S6: the position of the thermal infrared imager is adjusted through the two-dimensional slide rail, so that the black body furnace completely covers the square No. AR01 in the preview picture of the thermal infrared imager, as shown in FIG. 4.
S7: record current thermal infrared imager measurementsAnd (4) obtaining an image. Two-dimensional temperature data matrix of No. 1 square obtained by reading thermal image1Tm1。1Tm1As follows:
Figure BDA0003190062060000061
s8: and adjusting the position of the thermal infrared imager on the two-dimensional slide rail to enable the black body furnace to completely cover the square No. AR02 in the preview picture of the thermal infrared imager, as shown in FIG. 5.
S9: recording the image measured by the current thermal infrared imager, and reading the thermal image to obtain a two-dimensional temperature data matrix of an AR02 square2Tm1。2Tm1As follows:
Figure BDA0003190062060000062
s10: sequentially moving the thermal infrared imagers through two-dimensional slide rails, enabling the black-body furnace to completely cover each square in a preview picture of the thermal infrared imagers, recording thermal images, reading measured values of all pixel points in each square and storing the measured values as temperature matrixes respectively3Tm1、4Tm1、···12Tm1。
S11: setting the temperature of the black body furnace to T2And (4) continuing to wait for 20 minutes after the reading of the black body furnace reaches the set value so that the temperature of the black body furnace is stabilized.
S12: and adjusting the position of the thermal infrared imager through a two-dimensional slide rail, so that the black body furnace completely covers the square No. AR01 in the preview picture of the thermal infrared imager.
S13: and recording the image measured by the current thermal infrared imager. Two-dimensional temperature data matrix of block AR01 obtained by reading thermal image1Tm2。1Tm2As follows:
Figure BDA0003190062060000071
s14: and adjusting the position of the thermal infrared imager through a two-dimensional slide rail, so that the black body furnace completely covers the square No. AR02 in the preview picture of the thermal infrared imager.
S15: and recording the image measured by the current thermal infrared imager. Two-dimensional temperature data matrix of block AR02 obtained by reading thermal image2Tm2。2Tm2As follows:
Figure BDA0003190062060000072
s16: sequentially moving the thermal infrared imagers through two-dimensional slide rails, enabling the black-body furnace to completely cover each square in a preview picture of the thermal infrared imagers, recording thermal images, reading measured values of all pixel points in each square and storing the measured values as temperature matrixes respectively3Tm2、4Tm2、···12Tm2。
S17: for the square No. AR01 at 0-100 ℃, the temperature T of the black body furnace1At 40 ℃ the temperature matrix measured is1Tm1(ii) a When black body furnace temperature T2At 80 ℃ the measured temperature matrix is1Tm2And has:
1Tm1(i,j)＝1K0～100(i,j)T1+1B0～100(i,j) (9)
1Tm2(i,j)＝1K0～100(i,j)T2+1B0～100(i,j) (10)
wherein (i, j) is the coordinate of each pixel point in the square of AR01, i is more than or equal to 0, and j is less than or equal to 80. Calculating an attenuation coefficient matrix of an AR01 square within 0-100 ℃ by using the combined type (9) and (10)1K0～100And a matrix of drift coefficients1B0～100。
Attenuation coefficient matrix1K0～100As follows:
Figure BDA0003190062060000081
matrix of drift coefficients1B0～100As follows:
Figure BDA0003190062060000082
s18: repeating the step S17, and respectively calculating the attenuation coefficient matrixes of 12 squares within 0-100 DEG CnK0～100And a matrix of drift coefficientsnB0～100. Therefore, the calibration of imaging nonuniformity of the thermal infrared imager within 0-100 ℃ is completed.
S19: and changing the temperature of the black body furnace, calibrating the thermal infrared imager at the target temperature sections of 100-200 ℃, 200-300 ℃, 300-400 ℃ and 400-500 ℃ according to the method of the steps S5-S18, and respectively calculating the attenuation coefficient matrix and the drift coefficient matrix of each square block in each temperature section.
S20: when the calibrated thermal infrared imager is used for measuring the temperature, for a point with the coordinate (x, y) in the nth block of the thermal image, the measured value of the point in the thermal image is TmeasureAnd (4) calculating the real temperature T of the measured target corresponding to the point by using the formula (8).
Figure BDA0003190062060000083
The foregoing shows and describes the general principles, essential features, and inventive features of this invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (6)

1. A calibration method for imaging heterogeneity of a thermal infrared imager is characterized by comprising the following steps:
(1) dividing a calibration temperature section according to the dynamic range of the thermal infrared imager;
(2) dividing a calibration area according to the resolution of the thermal infrared imager;
(3) measuring the temperature of the black body furnace in each calibration area of the infrared thermal image in each temperature section;
(4) acquiring a calibration coefficient of each pixel point of the thermal infrared imager in the whole temperature measurement range;
(5) and calculating the corrected target temperature according to the calibration coefficient.
2. The method as claimed in claim 1, wherein in step (1), the dynamic range of the thermal infrared imager is divided into continuous calibration temperature sections according to a gradient, and the highest temperature and the lowest temperature of each calibration temperature section are TmaxAnd Tmin。
3. The method according to claim 1, characterized in that step (2) comprises in particular the steps of:
(2.1) dividing the thermal image of the thermal infrared imager into mutually connected calibration areas in a grid shape according to the resolution of the thermal infrared imager detector;
(2.2) setting the calibration area at the upper left corner as a No. 1 square, and numbering the rest calibration areas in sequence from left to right and from top to bottom.
4. The method according to claim 1, characterized in that step (3) comprises in particular the steps of:
(3.1) mounting the thermal infrared imager on a base, wherein the base is mounted on a horizontal sliding rail, and the horizontal sliding rail can integrally move on a sliding rail in the vertical direction;
(3.2) selecting the temperature section to be calibrated and determining good TmaxAnd TminTwo temperature values T are selected1And T2To satisfy Tmin＜T1＜T2＜TmaxSetting the temperature of the black body furnace to T1；
(3.3) adjusting the horizontal and vertical positions of the thermal infrared imager without changing the position of the black body furnace, adjusting the position of the black body furnace in a preview picture of the thermal infrared imager to be a No. 1 square, and completely filling the No. 1 square;
(3.4) recording the thermal image of the thermal infrared imager, reading the temperature value of each pixel point of the No. 1 square in the thermal image, and acquiring a No. 1 square two-dimensional temperature data matrix1Tm1And has:
Figure FDA0003190062050000011
wherein the left subscript 1 of each item represents square No. 1 of the thermal image obtained by the measurement;
1Tm1(i, j) represents the measured value corresponding to the pixel point of the ith row and the jth column in the No. 1 square;
T1(i, j) represents the temperature value of the measured object, namely the blackbody furnace, corresponding to the pixel point of the ith row and jth column in the block No. 1 of the measured thermal image, and T is1(i,j)＝T1；
Figure FDA0003190062050000021
Indicating the temperature interval Tmin～TmaxAttenuation coefficients of all pixel points of the inner No. 1 square;
Figure FDA0003190062050000022
indicating the temperature interval Tmin～TmaxDrift coefficients of all pixel points of the inner No. 1 square;
(3.5) moving the position of the thermal infrared imager through a horizontal sliding rail, adjusting the position of the black body furnace in a preview picture of the thermal infrared imager to be in the No. 2 square block, and completely covering the No. 2 square block;
(3.6) recordingReading the temperature value of each pixel point of No. 2 square in the thermal image of the thermal infrared imager, and acquiring a No. 2 square two-dimensional temperature data matrix2Tm1And has:
Figure FDA0003190062050000023
wherein the left subscript 2 of each item represents square No. 2 of the thermal image obtained by the measurement;
2Tm1(i, j) represents the measured value corresponding to the pixel point in the ith row and the jth column in the No. 2 square;
T1(i, j) represents the temperature value of the measured object, i.e. the blackbody furnace, corresponding to the pixel point in the ith row and jth column in the block No. 2 of the thermal image obtained by measurement, and has T1(i,j)＝T1；
Figure FDA0003190062050000024
Indicating the temperature interval Tmin～TmaxAttenuation coefficients of all pixel points of the inner No. 2 square;
Figure FDA0003190062050000025
indicating the temperature interval Tmin～TmaxDrift coefficients of all pixel points of the inner No. 2 square;
(3.7) moving the position of the thermal infrared imager through the horizontal and vertical sliding rails, sequentially adjusting the position of the black body furnace in the preview picture of the thermal infrared imager to the rest blocks, completely covering each block, recording thermal images, and sequentially obtaining a relational expression between a two-dimensional temperature data matrix of each block and the temperature of the black body furnace;
(3.8) setting the Black body furnace temperature to T2Moving the thermal infrared imager, adjusting the position of the black body furnace in the preview picture of the thermal infrared imager to be a No. 1 square, and completely filling the No. 1 square;
(3.9) recording the thermal image of the thermal infrared imager, and reading each image of the square No. 1 in the thermal imageObtaining the two-dimensional temperature data matrix of No. 1 block according to the temperature values of the prime points1Tm2And has:
Figure FDA0003190062050000026
wherein the left subscript 1 of each item represents square No. 1 of the thermal image obtained by the measurement;
1Tm2(i, j) represents the measured value corresponding to the pixel point of the ith row and the jth column in the No. 1 square;
T2(i, j) represents the temperature value of the measured object, namely the blackbody furnace, corresponding to the pixel point of the ith row and jth column in the block No. 1 of the measured thermal image, and T is2(i,j)＝T2；
Figure FDA0003190062050000027
Indicating the temperature interval Tmin～TmaxAttenuation coefficients of all pixel points of the inner No. 1 square;
Figure FDA0003190062050000028
indicating the temperature interval Tmin～TmaxDrift coefficients of all pixel points of the inner No. 1 square;
and (3.10) moving the thermal infrared imagers through the horizontal sliding rail and the vertical sliding rail, respectively adjusting the positions of the black body furnace in the preview picture of the thermal infrared imager into the rest blocks in sequence, completely covering each block, repeating the step (3.9), recording the thermal images, and sequentially obtaining the relational expression between the two-dimensional temperature data matrix of each block and the temperature of the black body furnace.
5. The method according to claim 1, characterized in that step (4) comprises in particular the steps of:
(4.1) for block number 1 in step (2.2), the following equation set:
Figure FDA0003190062050000031
Figure FDA0003190062050000032
attenuation coefficient matrix of block 1
Figure FDA0003190062050000033
And a matrix of drift coefficients
Figure FDA0003190062050000034
This can be obtained by the following equations (6) and (7):
Figure FDA0003190062050000035
Figure FDA0003190062050000036
(4.2) sequentially calculating the temperature sections T of all squares according to the method in (4.1)min～TmaxAttenuation coefficient matrix of
Figure FDA0003190062050000037
And a matrix of drift coefficients
Figure FDA0003190062050000038
6. The method of claim 1, wherein in step (5), the thermal image has a measurement T for the point with coordinate (x, y) in block nmeasureIf the measured target true temperature corresponding to the point is T, the calculation formula is shown as the formula (8):
Figure FDA0003190062050000039
CN202110875174.2A 2021-07-30 2021-07-30 Method for calibrating imaging heterogeneity of thermal infrared imager Active CN113670445B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110875174.2A CN113670445B (en) 2021-07-30 2021-07-30 Method for calibrating imaging heterogeneity of thermal infrared imager

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110875174.2A CN113670445B (en) 2021-07-30 2021-07-30 Method for calibrating imaging heterogeneity of thermal infrared imager

Publications (2)

Publication Number Publication Date
CN113670445A true CN113670445A (en) 2021-11-19
CN113670445B CN113670445B (en) 2022-10-18

Family

ID=78540914

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110875174.2A Active CN113670445B (en) 2021-07-30 2021-07-30 Method for calibrating imaging heterogeneity of thermal infrared imager

Country Status (1)

Country Link
CN (1) CN113670445B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115598177A (en) * 2022-12-14 2023-01-13 西南交通大学（Cn） Differential method based vehicle-mounted cable internal thermal defect contour detection method

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012154777A (en) * 2011-01-26 2012-08-16 National Institute Of Advanced Industrial & Technology Thermal radiation light source
CN105987758A (en) * 2015-02-05 2016-10-05 南京理工大学 Non-uniformity correction method of non-barrier infrared thermal imaging system
CN109060140A (en) * 2018-07-19 2018-12-21 中国科学院西安光学精密机械研究所 Infrared Image Non-uniformity Correction method based on multi-point calibration and fitting
CN109540297A (en) * 2018-10-23 2019-03-29 昆山优尼电能运动科技有限公司 Thermal infrared imager scaling method based on FPA temperature
CN109813440A (en) * 2019-03-12 2019-05-28 烟台艾睿光电科技有限公司 A kind of thermal infrared imager caliberating device, thermometric scaling method
CN110095192A (en) * 2019-04-26 2019-08-06 南京理工大学 A kind of thermal infrared imager comprehensive performance parameter test macro and its method
CN113175998A (en) * 2021-03-26 2021-07-27 合肥工业大学 Metal material surface temperature measurement method based on colorimetric temperature measurement

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012154777A (en) * 2011-01-26 2012-08-16 National Institute Of Advanced Industrial & Technology Thermal radiation light source
CN105987758A (en) * 2015-02-05 2016-10-05 南京理工大学 Non-uniformity correction method of non-barrier infrared thermal imaging system
CN109060140A (en) * 2018-07-19 2018-12-21 中国科学院西安光学精密机械研究所 Infrared Image Non-uniformity Correction method based on multi-point calibration and fitting
CN109540297A (en) * 2018-10-23 2019-03-29 昆山优尼电能运动科技有限公司 Thermal infrared imager scaling method based on FPA temperature
CN109813440A (en) * 2019-03-12 2019-05-28 烟台艾睿光电科技有限公司 A kind of thermal infrared imager caliberating device, thermometric scaling method
CN110095192A (en) * 2019-04-26 2019-08-06 南京理工大学 A kind of thermal infrared imager comprehensive performance parameter test macro and its method
CN113175998A (en) * 2021-03-26 2021-07-27 合肥工业大学 Metal material surface temperature measurement method based on colorimetric temperature measurement

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115598177A (en) * 2022-12-14 2023-01-13 西南交通大学（Cn） Differential method based vehicle-mounted cable internal thermal defect contour detection method

Also Published As

Publication number Publication date
CN113670445B (en) 2022-10-18

Similar Documents

Publication Publication Date Title
US9989405B2 (en) Infrared sensing devices and methods
CN103528694B (en) A kind of method of temperature of infrared heat image instrument measuring target object
WO2022121562A1 (en) Devices and methods for temperature measurment
CN109791699B (en) Radiation imaging
CN107340064B (en) Thermal imaging system heterogeneity based on scan rectangle black matrix evaluates means for correcting
US10345154B2 (en) Infrared sensing devices and methods
CN111272290B (en) Temperature measurement thermal infrared imager calibration method and device based on deep neural network
CN113670445B (en) Method for calibrating imaging heterogeneity of thermal infrared imager
CN112146763B (en) Temperature measurement method and system based on automatic identification
CN109540297B (en) Infrared thermal imager calibration method based on FPA temperature
CN110006529B (en) Output correction method and device for infrared detection device
Lin et al. Pixel-wise radiometric calibration approach for infrared focal plane arrays using multivariate polynomial correction
WO2022023748A1 (en) A thermal imaging system and method
CN109087341B (en) Fusion method of close-range hyperspectral camera and ranging sensor
CN116878669A (en) Temperature compensation method based on short wave infrared temperature measurement, fire monitoring method and system
Jin et al. Infrared nonuniformity correction and radiometric calibration technology using U-shaped blackbody
Gutschwager et al. Nonuniformity correction of infrared cameras by reading radiance temperatures with a spatially nonhomogeneous radiation source
CN106908153B (en) A kind of modified method of surface of revolution infrared measurement of temperature
Gonzalez-Chavez et al. Radiometric calibration of digital counts of infrared thermal cameras
CN113970374A (en) Calibration method for polarization detection system of focal plane
CN114061761B (en) Remote target temperature accurate measurement method based on monocular infrared stereoscopic vision correction
CN110595626A (en) Infrared detector system and imaging method
Mansor et al. CALIBRATION OF LIGHTWEIGHT THERMAL SENSOR FOR FULLY AUTONOMOUS UAV
CN117053928A (en) Calibration method for thermal infrared imager lens distortion correction and imaging non-uniformity
Elfner et al. Surface Temperature Measurement on Complex Topology by Infrared Thermography

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant