A non-uniformity correction method based on derivative domain response rate correction

Abstract

The present application relates to a kind of non-uniformity correction method based on derivative domain response rate correction, it includes the following steps: setting temperature different blackbody;The image of each blackbody is obtained by infrared imaging device, and the response of infrared detector to current blackbody temperature when each blackbody image is acquired is collected;Based on the response to current blackbody temperature, response curve function of each pixel to different blackbody temperature is obtained by fitting, and the response rate of each pixel at any temperature is correspondingly obtained;The response rate of each pixel is corrected;Non-uniformity correction is carried out to infrared image, and the corrected infrared image is output.The present application can be based on the theoretical basis that the response of pixel to different radiation is nonlinear relationship, accurately describe the response rate of each pixel in derivative domain, and further non-uniformity correction is carried out to the response rate of each pixel, to obtain more accurate nonlinear response curve and corrected infrared image, thereby reduce the noise of infrared image, improve temperature measurement result accuracy.

Description

Technical Field

[0001] The present invention relates to the field of infrared imaging technology, and in particular to a non-uniformity correction method based on derivative domain response rate correction. Background Art

[0002] During infrared imaging, the response characteristics of each pixel on the infrared detector cannot be guaranteed to be completely consistent, resulting in the same amount of thermal radiation producing different grayscale values ​​at different pixels in the image. This characteristic of the infrared detector is called non-uniformity, which needs to be corrected through an algorithm to ensure the accuracy of the infrared temperature measurement results.

[0003] Common non-uniformity correction algorithms include single-point correction and two-point correction. The single-point correction algorithm assumes that the response difference of the pixel is a fixed value that does not change with the target temperature. Therefore, correction is achieved by subtracting a fixed value from the pixel value of each pixel in the image.

[0004] The two-point correction algorithm is the more commonly used non-uniformity correction method. It assumes that the response of the pixel is linearly related to the target temperature, and there are differences in response rate and bias. It needs to be implemented through the gain matrix that controls the slope and the background matrix that controls the bias.

[0005] However, the two-point correction algorithm has the following problems when performing non-uniformity correction: 1) The theoretical basis of the two-point correction algorithm assumes that the response curve of the pixel is linear, but this linear relationship does not match the actual response curve, which can easily lead to poor non-uniformity correction effect in some scenes; 2) When performing response rate correction, the two-point correction algorithm uses the ratio of the difference in grayscale values ​​to the target temperature difference to evaluate the response rate. This method obtains the average response rate in a certain temperature range and cannot accurately describe the response rate of the response curve at each temperature point. Summary of the Invention

[0006] The purpose of the present invention is to provide a non-uniformity correction method based on derivative domain response rate correction. The method is based on the theoretical basis that the response of pixels to different radiation amounts is a nonlinear relationship. The response rate of each pixel is accurately described in the derivative domain, and the non-uniformity correction of the response rate of each pixel is further performed to obtain a more accurate nonlinear response curve and a corrected infrared image, thereby reducing the noise of the infrared image and improving the accuracy of the temperature measurement results.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A non-uniformity correction method based on derivative domain responsivity correction is provided, which includes the following steps:

[0009] Set up N blackbodies with different temperatures;

[0010] Acquire an image of each black body through an infrared imaging device, and collect the response of the infrared detector of the infrared imaging device to the current black body temperature when acquiring each black body image;

[0011] Based on the infrared detector's response to the current blackbody temperature, the response curve function f(T; P) of each pixel to different blackbody temperatures is fitted, and the response curve function f(T; P) of each pixel is differentiated to obtain the corresponding response rate f′(T; P) of each pixel at any temperature;

[0012] Correct the response rate f'(T; P) of each pixel so that the response rate f'(T; P) of each pixel is the same as the preset response rate, and record the response rate correction parameter set Q of each pixel during the correction process;

[0013] Perform non-uniformity correction on the infrared image and output the corrected infrared image.

[0014] Preferably, the response curve function f(T; P) is a quadratic polynomial curve obtained based on fitting, and its expression is shown in formula (1):

[0015] f (T；P) =p1×T 2 +p2×T+p3 (1)

[0016] Among them, T is the blackbody temperature; P is the response curve parameter set of the current pixel to different blackbody temperatures; p1, p2, and p3 are all parameters in the response curve parameter set.

[0017] Preferably, the response rate f′(T; P) of each pixel is corrected so that the response rate f′(T; P) of each pixel is the same as the preset response rate, including the following steps:

[0018] Get the center point response rate f′ of the center point of the image c(T；P) ;

[0019] Construct the center point response rate f′ c(T；P) The response rate f′ of any point in the image x(T；P) The mapping relationship g between them makes the response rate f′ of any point in the image x(T；P) The central point response rate f′ c(T；P) same.

[0020] Preferably, the response rate f′(T; P) of each pixel is corrected so that the response rate f′(T; P) of each pixel is the same as the preset response rate, including the following steps:

[0021] The full-image response mean value A of all pixels when the infrared imaging device acquires each blackbody image is calculated;

[0022] The full-image response mean curve f is obtained by fitting the full-image response mean A. m(T；A) , where T is the blackbody temperature;

[0023] The mean response curve f for the entire graph m(T；A) Derivative, get the average response rate f' of the whole graph m(T；A) ;

[0024] Construct the average response rate f' of the entire graph m(T；A) The response rate f′ of any point in the image x(T；P) The mapping relationship g between them makes the response rate f′ of any point in the image x(T；P) The average response rate of the whole graph f' m(T；A) same.

[0025] Preferably, performing non-uniformity correction on the infrared image and outputting the corrected infrared image specifically includes the following steps:

[0026] Obtain an infrared image of the current target through an infrared imaging device, and obtain the current response rate of each pixel;

[0027] The target temperature T is calculated based on the current response rate of each pixel;

[0028] The current response rate of the current pixel is corrected according to the response rate correction parameter set Q of each pixel to obtain a nonlinear response curve after the non-uniformity of each pixel is corrected, and a corrected infrared image is output.

[0029] Preferably, the current response rate of each pixel is corrected according to the response rate correction parameter set Q of each pixel to obtain a nonlinear response curve after the non-uniformity of each pixel is corrected, including the following steps:

[0030] pass The response rate f′ to the current pixel x x(T；P) Correction is made, where f xc (T) is the nonlinear response curve of the current pixel x after non-uniformity correction, g x (*) is the response rate f′ of the current pixel x x(T；P) and the central point response rate f′ c(T；P) Or the average response rate of the whole graph f' m(T；A) The mapping relationship between them.

[0031] Preferably, performing non-uniformity correction on the infrared image and outputting the corrected infrared image specifically includes the following steps:

[0032] Obtain an infrared image of the current target through an infrared imaging device, and obtain the true response of each pixel based on the infrared detector;

[0033] The target temperature T is calculated based on the following formula:

[0034]

[0035] Where T is the target temperature obtained by inverse calculation; G is the actual response of the current pixel;

[0036] Substitute the inversely calculated target temperature T and the true response G of the current pixel into the following formula to obtain the corrected response G1 of the current pixel:

[0037] G1=q1×G+q2×T+C

[0038] Set the shutter temperature T s , shutter response G s Substitute into the following formula to obtain the corrected shutter response G2 of the current pixel:

[0039] G2=q1×G s +q2×T s +C

[0040] The bias correction is performed on each pixel using the following formula to obtain the non-uniformity correction response value G3:

[0041] G3=G1-G2=q1×G+q2×T+C-q1×G s +q2×T s + C = q1 × (GG s )+q2×(TT s );

[0042] The corrected infrared image is output according to the non-uniformity correction response value G3 of each pixel to complete the non-uniformity correction.

[0043] Preferably, after the temperatures of all black bodies are arranged in descending or ascending order, the temperature intervals between every two adjacent black body temperatures are the same.

[0044] Preferably, before acquiring the first blackbody image, the infrared imaging device needs to be placed in a constant temperature environment after being turned on until the temperature of the focal plane of the infrared detector becomes constant.

[0045] Preferably, when the infrared imaging device acquires an image of any black body, the black body fills the entire imaging field of view.

[0046] In summary, the present invention has the following beneficial effects compared with the prior art:

[0047] The present invention is based on the theoretical foundation that the response of pixels to different amounts of radiation is a nonlinear relationship. It accurately describes the response rate of each pixel in the derivative domain and obtains a response rate correction parameter set for each pixel. The response rate of each pixel is further corrected for non-uniformity through integration and bias correction. At the same time, a more accurate nonlinear response curve and a corrected infrared image are obtained, thereby reducing the noise of the infrared image and improving the accuracy of the temperature measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is a flowchart of the steps of the non-uniformity correction method of the present invention;

[0049] Figure 2 These are infrared images without non-uniformity correction, after being processed by the conventional two-point correction method, and after being processed by the correction method of the present invention. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0051] Example 1

[0052] In the prior art, the infrared temperature measurement process is completed based on infrared imaging equipment. The infrared imaging equipment includes an infrared detector, which can sense the infrared radiation of the target object and convert it into an electrical signal. The temperature distribution of the target object is simulated by further processing the electrical signal to obtain the target object temperature. In this process, non-uniformity correction is required to ensure the accuracy of the infrared temperature measurement results and reduce infrared image noise.

[0053] On this basis, if Figure 1 As shown, this embodiment provides a non-uniformity correction method based on derivative domain responsivity correction, which includes the following steps:

[0054] S1. Set N blackbodies with different temperatures in the scene, where N is a positive integer greater than or equal to 5. At the same time, after the temperatures of all blackbodies are arranged in descending or ascending order, the temperature intervals between every two adjacent blackbodies are the same. For example, in this embodiment, a blackbody corresponding to 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, and 50°C can be set, for a total of 11 blackbodies;

[0055] S2. acquiring an image of each black body through an infrared imaging device, and collecting a response of the infrared detector of the infrared imaging device to the current black body temperature when acquiring each black body image;

[0056] Before acquiring the first blackbody image, the infrared imaging device must be placed in a constant temperature environment after being powered on until the temperature of the infrared detector focal plane becomes constant. The constant temperature of the infrared detector focal plane means that the temperature of the infrared detector focal plane fluctuates within a predetermined temperature range within a predetermined time period. The response includes an electrical signal obtained by converting the infrared radiation signal of the blackbody. This conversion process can be achieved by a corresponding conversion unit.

[0057] At the same time, when the infrared imaging device acquires an image of any black body, the black body fills the entire imaging field of view to ensure that the response of each pixel is related to the black body;

[0058] S3. Based on the response of the infrared detector to the current blackbody temperature, a response curve function f(T; P) of each pixel to different blackbody temperatures is obtained by fitting. In this embodiment, the response curve function f(T; P) can be a quadratic polynomial curve obtained based on the fitting, and its expression is shown in formula (1):

[0059] f(T;P)=p1=T 2 +p2×T+p3 (1)

[0060] Where T is the blackbody temperature; P is the response curve parameter set of the current pixel to different blackbody temperatures; p1, p2, and p3 are all parameters in the response curve parameter set;

[0061] For example, in this embodiment, the expression of the response curve function f(T; P) of each pixel is the same, such as the quadratic polynomial function mentioned above, and the horizontal coordinates are different blackbody temperatures, and the vertical coordinates are the responses of the same pixel to different blackbody temperatures. However, for different pixels, the parameters p1, p2, and p3 during fitting are different, so the response curve parameter set of the response curve function f(T; P) of each pixel is also different.

[0062] S4. Deriving the response curve function f(T; P) of each pixel to obtain the response rate f′(T; P) of each pixel at any temperature. For example, in this embodiment, if the response curve function f(T; P) is a quadratic polynomial curve, then the response rate f′(T; P) obtained by derivation is as shown in formula (2):

[0063] f′ (T；P) =2×p1×T+p2 (2)

[0064] Wherein, the meanings of T, p1, and p2 are the same as those in the above formula (1) and will not be repeated here;

[0065] S5. Correct the response rate f′(T; P) of each pixel so that the response rate f′(T; P) of each pixel is the same as the preset response rate, and record and store the response rate correction parameter set Q of each pixel during the correction process;

[0066] In this embodiment, the preset response rate includes the response rate of the pixel corresponding to the center point of the image, that is, the center point response rate, or the average response rate of the entire image;

[0067] Specifically, when the preset response rate = the center point response rate, first obtain the center point response rate f′ of the center point of the image. c(T；P) , and then construct the central point response rate f′ c(T；P) The response rate f′ of any point in the image x(T；P) The mapping relationship g between them makes the response rate f′ of any point in the image x(T；P) The central point response rate f′ c(T；P) Same as above, to complete the response rate correction of each pixel;

[0068] The above mapping process can be described by the following formula (3):

[0069]

[0070] The mapping relationship g can be any function, including but not limited to a linear function, a quadratic polynomial function, etc. Q is the pixel response rate correction parameter set of any point in the image, that is, any point in the image has a corresponding response rate f′ x(T；P) and a response rate correction parameter set Q, and the response rate correction parameter set Q of each pixel may be different, which can be determined according to the data fitting process, etc. during the actual construction of the mapping relationship g;

[0071] For example, if the mapping relationship g is a linear function, the response rate correction process of the above pixel can be described by formula (4):

[0072] f′ c(T；P) =q1×f′ x(T；P) +q2 (4)

[0073] Among them, q1 and q2 are parameters in the response rate correction parameter set Q;

[0074] If the response curve function f(T; P) is a quadratic linear function, the response rate correction process of the above pixel can be described by formulas (5)-(7):

[0075] 2×p c1 ×T+p c2 =q1×(2×p x1 ×T+p x2 )+q2 (5)

[0076]

[0077] q2=p c2 -q1×p x2 (7)

[0078] Among them, q1 and q2 are parameters in the response rate correction parameter set Q; p c1 、p c2 The response curve function f is the center point of the image c Parameters in the response curve parameter set P of (T; P); p x1 、p x2 The response curve function f is any point in the image. x Parameters in the response curve parameter set P of (T; P);

[0079] When the preset response rate = the full-image average response rate, first calculate the full-image response mean A of all pixels when the infrared imaging device acquires each blackbody image, and the full-image response mean A = the sum of all pixel responses in the current blackbody image / the total number of pixels in the current blackbody image; then, fit the full-image response mean curve f according to all full-image response mean A m(T；A) , where T is the blackbody temperature, the horizontal axis is the different blackbody temperatures, and the vertical axis is the mean value A of all full-image responses; continue to calculate the full-image response mean curve f m(T；A) By taking the derivative, we can get the average response rate f' of the whole graph. m(T；A) ;

[0080] Furthermore, the average response rate f' of the whole graph is constructed m(T；A) The response rate f′ of any point in the image x(T；P) The mapping relationship g between them makes the response rate f′ of any point in the image x(T；P) The average response rate of the whole graph f' m(T；A) Same, to complete the pixel response rate correction;

[0081] The above mapping process can be described by the following formula (8):

[0082]

[0083] The mapping relationship g can also be any function, including but not limited to a linear function, a quadratic polynomial function, etc. Q is the pixel response rate correction parameter set of any point in the image, that is, any point in the image has a corresponding response rate f′ x(T；P) and a response rate correction parameter set Q, and the response rate correction parameter set Q of each pixel may be different, and the response rate correction parameter set Q may also be determined according to the actual data fitting process, etc.;

[0084] At the same time, when the mapping relationship g is a linear function or a quadratic linear function, the corresponding pixel response rate correction process is the same as the mapping relationship g (i.e., the same as formula (4) and formulas (5)-(7) respectively), and will not be repeated here;

[0085] S6, performing non-uniformity correction on the infrared image and outputting the corrected infrared image, which specifically includes the following steps:

[0086] An infrared image of the current target (i.e., the target to be infrared temperature measured) is obtained through an infrared imaging device, and the response rate of each pixel is obtained based on the infrared detector;

[0087] The target temperature T is calculated based on the current response rate of each pixel;

[0088] Correcting the response rate of the current pixel according to the response rate correction parameter set Q of each pixel to obtain a nonlinear response curve after the non-uniformity correction of each pixel, thereby completing the non-uniformity correction and outputting a corrected infrared image;

[0089] The step of correcting the response rate of each pixel according to the response rate correction parameter set Q of each pixel to obtain a nonlinear response curve after the non-uniformity of each pixel is corrected includes the following steps:

[0090] pass The response rate f′ to the current pixel x(T；P) Correction is made, where f xc (T) is the nonlinear response curve of the current pixel after non-uniformity correction.

[0091] Therefore, this embodiment is based on the theoretical basis that the response of pixels to different radiation amounts (expressed as grayscale values ​​on the image) is a nonlinear relationship. It accurately describes the response rate of each pixel in the derivative domain and obtains the response rate correction parameter set Q of each pixel. The response rate of each pixel is further corrected for non-uniformity through integration, thereby obtaining a more accurate nonlinear response curve and a corrected infrared image.

[0092] like Figure 2 As shown, parts (a), (b), and (c) are infrared images without non-uniformity correction, after processing by the conventional two-point correction method, and after processing by the correction method in this embodiment, respectively. It can be seen that compared with the conventional two-point correction algorithm, the image noise obtained after correction by the method in this embodiment is significantly reduced, thereby helping to improve the temperature measurement accuracy.

[0093] Example 2:

[0094] The only difference between this embodiment and embodiment 1 is that if the center point response rate f′ of the image center point c(T；P)Or the average response rate of the whole graph f' m(T；A) The response rate f′ of any point in the image x(T；P) When the mapping relationship g between is a linear function, we have:

[0095]

[0096] Where C is an arbitrary constant value generated by the indefinite integral.

[0097] However, the constant value C mentioned above makes it impossible to obtain accurate correction results, and the constant value C corresponding to each pixel may be different. Therefore, it is necessary to eliminate this constant value C to obtain accurate temperature measurement results. Furthermore, since there are offset differences between each pixel, and infrared imaging devices are generally equipped with a shutter, the offset correction can be completed by subtracting the scene response when the shutter is closed from the shutter response to eliminate the constant value C.

[0098] Specifically, when the response curve is a quadratic polynomial function and the mapping relationship is a linear function, step S6 specifically includes the following steps:

[0099] The infrared image of the current target (i.e. the target to be measured by infrared temperature) is obtained through the infrared imaging device, and the real response of each pixel is obtained based on the infrared detector;

[0100] The target temperature T is calculated based on the following formula:

[0101]

[0102] Wherein, T is the target temperature obtained by inverse calculation; G is the true response of the current pixel, and the true response can be the gray value of the current pixel in the current infrared image;

[0103] Substitute the inversely calculated target temperature T and the true response G of the current pixel into the following formula to obtain the corrected response G1 of the current pixel:

[0104] G1=q1×G+q2×T+C

[0105] Similarly, the shutter temperature T s , shutter response G s (which can be the grayscale value of the current pixel in the shutter infrared image) is substituted into the following formula to obtain the corrected shutter response G2 of the current pixel:

[0106] G2=q1×G s +q2×T s +C

[0107] The bias correction is performed on each pixel using the following formula to obtain the non-uniformity correction response value G3:

[0108] G3=G1-G2=q1×G+q2×T+C-q1×G s +q2×T s + C = q1 × (GG s )+q2×(TT s );

[0109] The corrected infrared image is output according to the non-uniformity correction response value G3 of each pixel to complete the non-uniformity correction.

[0110] In summary, the present invention is based on the theoretical foundation that the response of pixels to different amounts of radiation (expressed as grayscale values ​​on the image) is a nonlinear relationship. It accurately describes the response rate of each pixel in the derivative domain and obtains the response rate correction parameter set Q of each pixel. The response rate of each pixel is further corrected for non-uniformity through integration and bias correction, and a more accurate nonlinear response curve and a corrected infrared image are obtained at the same time, thereby reducing the noise of the infrared image and improving the accuracy of the temperature measurement results.

[0111] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A non-uniformity correction method based on derivative domain responsivity correction, characterized in that: The steps include: Set up N blackbodies with different temperatures; Acquire an image of each black body through an infrared imaging device, and collect the response of the infrared detector of the infrared imaging device to the current black body temperature when acquiring each black body image; Based on the response of the infrared detector to the current blackbody temperature, the response curve function f of each pixel to different blackbody temperatures is obtained by fitting. (T；P) , and the response curve function f for each pixel (T；P) Derivative to obtain the response rate f′ of each pixel at any temperature (T；P) ; The response rate f′ for each pixel (T；P) Correction is made so that the response rate f′ of each pixel (T；P) The response rates are the same as the preset response rates, and the response rate correction parameter set Q of each pixel is recorded during the correction process; Performing non-uniformity correction on the infrared image and outputting the corrected infrared image; The response curve function f (T；P) is the quadratic polynomial curve obtained based on fitting, and its expression is shown in formula (1): f (T；P) =p1×T 2 +p2×T+p3(1) Where T is the blackbody temperature; P is the response curve parameter set of the current pixel to different blackbody temperatures; p1, p2, and p3 are all parameters in the response curve parameter set; Performing non-uniformity correction on the infrared image and outputting the corrected infrared image specifically includes the following steps: Obtain an infrared image of the current target through an infrared imaging device, and obtain the current response rate of each pixel; The target temperature T is calculated based on the current response rate of each pixel; The current response rate of the current pixel is corrected according to the response rate correction parameter set Q of each pixel to obtain a nonlinear response curve after the non-uniformity of each pixel is corrected, and a corrected infrared image is output.

2. The non-uniformity correction method according to claim 1, wherein: The response rate f′ for each pixel (T；P) Correction is made so that the response rate f′ of each pixel (T；P) The same as the preset response rate, including the following steps: Get the center point response rate f′ of the center point of the image c(T；P) ; Construct the center point response rate f′ c(T；P) The response rate f′ of any point in the image x(T；P) The mapping relationship g between them makes the response rate f′ of any point in the image x(T；P) The central point response rate f′ c(T；P) same.

3. The non-uniformity correction method according to claim 1, wherein: The response rate f′ for each pixel (T；P) Correction is made so that the response rate f′ of each pixel (T；P) The same as the preset response rate, including the following steps: The full-image response mean value A of all pixels when the infrared imaging device acquires each blackbody image is calculated; The full-image response mean curve f is obtained by fitting the full-image response mean A. m(T；A) , where T is the blackbody temperature; The mean response curve f for the entire graph m(T；A) Derivative, get the average response rate f′ of the whole graph m(T；A) ; Construct the average response rate f′ of the entire graph m(T；A) The response rate f′ of any point in the image x(T；P) The mapping relationship g between them makes the response rate f′ of any point in the image x(T；P) The average response rate of the whole map f′ m(T；A) same.

4. The non-uniformity correction method according to claim 1, wherein: The current response rate of each pixel is corrected according to the response rate correction parameter set Q of each pixel to obtain a nonlinear response curve after the non-uniformity of each pixel is corrected, including the following steps: pass The response rate f′ to the current pixel x x(T；P) Correction is made, where f x(T) That is, the nonlinear response curve of the current pixel x after non-uniformity correction, g x (*) is the response rate f′ of the current pixel x x(T；P) and the central point response rate f′ c(T；P) Or the average response rate of the whole map f′ m(T；A) The mapping relationship between them.

5. The non-uniformity correction method according to claim 1, wherein: Performing non-uniformity correction on the infrared image and outputting the corrected infrared image specifically includes the following steps: Obtain an infrared image of the current target through an infrared imaging device, and obtain the true response of each pixel based on the infrared detector; The target temperature T is calculated based on the following formula: Where T is the target temperature obtained by inverse calculation; G is the actual response of the current pixel; Substitute the inversely calculated target temperature T and the true response G of the current pixel into the following formula to obtain the corrected response G1 of the current pixel: G1=q1×G+q2×T+C Set the shutter temperature T s , shutter response G s Substitute into the following formula to obtain the corrected shutter response G2 of the current pixel: G2=q1×G s +q2×T s +C The bias correction is performed on each pixel using the following formula to obtain the non-uniformity correction response value G3: G3=G1-G2=q1×G+q2×T+C-q1×G s +q2×T s +C=q1×(G-G s )+q2×(T-T s ); The corrected infrared image is output according to the non-uniformity correction response value G3 of each pixel to complete the non-uniformity correction.

6. The non-uniformity correction method according to claim 1, wherein: After arranging the temperatures of all black bodies in descending or ascending order, the temperature interval between every two adjacent black body temperatures is the same.

7. The non-uniformity correction method according to claim 1, wherein: Before acquiring the first blackbody image, the infrared imaging device must be placed in a constant temperature environment after being turned on until the temperature of the infrared detector focal plane becomes constant.

8. The non-uniformity correction method according to claim 1, wherein: When an infrared imaging device acquires an image of any black body, the black body fills the entire imaging field of view.

Images