A method and apparatus for relative radiometric correction of wide-swath mid-wave infrared remote sensing images

Abstract

This invention discloses a method and apparatus for relative radiometric correction of wide-swath mid-wave infrared remote sensing images, relating to the field of image correction technology. The method includes: acquiring an infrared remote sensing image to be processed; determining corresponding correction coefficients based on two adjacent detector units in each monolithic linear array of the infrared remote sensing image; obtaining residuals based on the output signals of the two detector units and the corresponding correction coefficients; determining high-quality signals based on the residuals; repeating the above process to obtain high-quality signals from all monolithic linear arrays in the infrared remote sensing image as a monolithic linear array screening signal set; forming a high-quality signal set based on all the monolithic linear array screening signal sets; obtaining correction parameters based on the monolithic linear array screening signal set and the high-quality signal set; and correcting the output signals of all monolithic linear arrays in the infrared remote sensing image based on the correction parameters to obtain a corrected infrared remote sensing image. This method achieves non-uniformity correction of infrared remote sensing images and accurately restores the radiometric information of ground objects.

Description

Technical Field

[0001] This invention relates to the field of image correction technology, and more specifically to a method and apparatus for relative radiometric correction of wide-swath mid-wave infrared remote sensing images. Background Technology

[0002] Currently, spaceborne pushbroom wide-swath infrared cameras can perceive surface information around the clock within an ultra-wide field of view, playing a significant role in remote sensing applications such as ecological environment monitoring, agricultural asset assessment, and disaster early warning. However, limited by the imaging mechanism of spaceborne infrared sensors, on the one hand, infrared images are characterized by low intrinsic contrast, making it difficult to accurately distinguish ground features in uncorrected infrared images; on the other hand, the responses of various photosensitive components in infrared detectors are inconsistent, resulting in noticeable textures in the output images even against a uniform background. Furthermore, the imaging optical system of a wide-swath mid-wave infrared detector has a larger volume and more complex optical path than the imaging optical system of a traditional infrared detector, significantly amplifying the degradation effect of instability on infrared images.

[0003] Relative radiometric correction techniques for pushbroom infrared array cameras have been greatly improved, with the most widely used being the on-board blackbody-based radiometric calibration method. This method requires a full-aperture, full-optical-path blackbody calibration device in the imaging system. However, for large-field-of-view, high-resolution infrared cameras, designing a full-aperture, full-optical-path calibration blackbody in the imaging system is technically challenging, costly, and not highly feasible. Therefore, this method cannot be used for ground radiometric correction, requiring the reliance on single-track statistical methods to correct image non-uniformity. Traditional single-track statistical methods, such as the standard moment matching algorithm, when the differences in ground object information acquired by each detector unit are significant, alter the true radiometric characteristics of the ground objects while suppressing inter-pixel radiometric differences. This results in unstable correction effects and a significant impact on subsequent applications.

[0004] Therefore, how to achieve non-uniformity correction of infrared remote sensing images and thus accurately restore the radiation information of ground objects is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a relative radiometric correction method and apparatus for wide-swath mid-wave infrared remote sensing images, which realizes the correction of non-uniformity of infrared remote sensing images and thus accurately restores the radiometric information of ground objects.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A relative radiometric correction method for wide-swath mid-wave infrared remote sensing images includes:

[0008] Acquire the infrared remote sensing image to be processed;

[0009] The corresponding correction coefficients are determined based on the two adjacent detector units in each monolithic linear array of the infrared remote sensing image.

[0010] The residual is obtained based on the output signals of the two detector units and the corresponding correction coefficients;

[0011] A high-quality signal is obtained based on the residual judgment;

[0012] Repeat the above process to obtain the high-quality signals from all single linear arrays in the infrared remote sensing image as the single linear array screening signal set;

[0013] A high-quality signal set is formed by filtering all the aforementioned single-chip linear array signals.

[0014] Correction parameters are obtained based on the single-chip linear array filtered signal set and the high-quality signal set;

[0015] The output signals of all the single-chip linear arrays in the infrared remote sensing image are corrected based on the correction parameters to obtain a corrected infrared remote sensing image.

[0016] Preferably, the method for determining the correction coefficient is as follows:

[0017] Based on the laboratory calibration strategy of the mid-wave infrared camera, the correction coefficients corresponding to the detector unit are determined by using a blackbody radiation source.

[0018] The correction coefficients include: gain coefficient and intercept factor.

[0019] Preferably, the residual acquisition method is as follows:

[0020] The residual detH is obtained based on the output signals of the two adjacent detector units and the corresponding correction coefficients:

[0021] detH=(k i ×Y i -k j ×Y j )-(b j -b i );

[0022] Where, k i k represents the gain coefficient of the i-th detector element. j Y represents the gain coefficient of the j-th detector element, where the i-th detector element is adjacent to the j-th detector element. i Y represents the output signal of the i-th detector unit. j b represents the output signal of the j-th detector unit. i b represents the intercept factor of the i-th detector element. jThis represents the intercept factor of the j-th detector element.

[0023] Preferably, obtaining a high-quality signal based on the residual judgment specifically includes:

[0024] Determine whether the absolute value of the residual is less than a threshold;

[0025] If so, the output signals of the two adjacent detector units are taken as the high-quality signal;

[0026] Otherwise, continue to judge the residuals of other two adjacent detector units in sequence until all detector units in the current monolithic linear array have been judged, and all the high-quality signals in the current monolithic linear array are obtained.

[0027] Preferably, the method for obtaining the correction parameters is as follows:

[0028] Based on all high-quality signals in the single-chip linear array screening signal set, the mean and variance of the single-chip linear array are used together as the first parameter.

[0029] The overall mean and overall variance of all high-quality signals in the high-quality signal set are used together as the second parameter.

[0030] The correction parameters are composed of the first parameter and the second parameter.

[0031] Preferably, the mean value u of the single-chip linear array i and the variance δ of the single linear array i They are respectively:

[0032]

[0033] Among them, Y i,j This indicates the high-quality signal selected from the signal set of the single linear array, where i represents the sequence number of the single linear array, j represents the sequence number of the detector unit, and M represents the number of imaging output rows.

[0034] Preferably, the overall mean u r and the total variance δ r They are respectively:

[0035]

[0036]

[0037] Where N represents the number of single linear arrays.

[0038] Preferably, the method for acquiring the corrected infrared remote sensing image is as follows:

[0039] Based on the correction parameters, the output signals of all the single-chip linear arrays in the infrared remote sensing image are corrected according to the corresponding single-chip linear arrays to obtain the corrected single-chip linear array output code value.

[0040] The corrected infrared remote sensing image is obtained based on all the output code values ​​of the single-chip linear array.

[0041] Preferably, the output code value of the single-chip linear array is specifically:

[0042]

[0043] Among them, Y i,j ' indicates the corrected output code value of the monolithic linear array.

[0044] A relative radiometric correction device for a wide-swath mid-wave infrared remote sensing image includes: an image acquisition module, a correction coefficient acquisition module, a high-quality signal determination module, a signal set acquisition module, a correction parameter acquisition module, and an image correction module;

[0045] The image acquisition module is used to acquire the infrared remote sensing image to be processed;

[0046] The correction coefficient acquisition module is used to determine the corresponding correction coefficient based on two adjacent detector units in each single linear array of the infrared remote sensing image.

[0047] The high-quality signal determination module is used to obtain the residual based on the output signals of the two detector units and the corresponding correction coefficients; and to determine the high-quality signal based on the residual.

[0048] The signal set acquisition module is used to repeat the above process to obtain the high-quality signals from all single-chip linear arrays in the infrared remote sensing image as a single-chip linear array screening signal set; and to form a high-quality signal set based on all the single-chip linear array screening signal sets.

[0049] The correction parameter acquisition module is used to obtain correction parameters based on the single-chip linear array filtered signal set and the high-quality signal set.

[0050] The image correction module is used to correct the output signals of all the single-chip linear arrays in the infrared remote sensing image based on the correction parameters, so as to obtain a corrected infrared remote sensing image.

[0051] As can be seen from the above technical solution, compared with the prior art, this invention discloses a relative radiometric correction method and apparatus for wide-swath mid-wave infrared remote sensing images. This invention is based on the imaging mechanism of mid-wave infrared detectors and utilizes the radiometric characteristics of the camera system as the sample control basis in the scene method. After selecting reasonable high-quality samples, the non-uniformity correction coefficients of each detector unit are calculated. During the calculation process, this apparatus maintains the stability of the detector unit gain coefficients and is less affected by statistical differences caused by samples in the imaging scene, demonstrating strong algorithm robustness. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0053] Figure 1 A flowchart of a relative radiometric correction method for wide-swath mid-wave infrared remote sensing images provided by the present invention.

[0054] Figure 2 A schematic diagram of the photoelectric response curves of the camera system with 6 detectors provided by the present invention, obtained from a uniform blackbody at different temperatures.

[0055] Figure 3 The original daytime image provided for this invention.

[0056] Figure 4 The original nighttime image provided for this invention.

[0057] Figure 5 The daytime image corrected by the moment matching method provided in this invention.

[0058] Figure 6 The daytime image corrected by the method of the present invention.

[0059] Figure 7 The nighttime image corrected by the moment matching method provided by this invention.

[0060] Figure 8 The nighttime image corrected by the method of the present invention.

[0061] Figure 9 This is a schematic diagram of a relative radiometric correction device for wide-swath mid-wave infrared remote sensing images provided by the present invention. Detailed Implementation

[0062] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0063] Example 1

[0064] like Figure 1 As shown, this embodiment of the invention discloses a relative radiometric correction method for wide-swath mid-wave infrared remote sensing images, comprising:

[0065] Acquire the infrared remote sensing image to be processed;

[0066] The corresponding correction coefficients are determined based on the two adjacent detector units in each monolithic linear array of the infrared remote sensing image.

[0067] The residual is obtained based on the output signals of the two detector units and the corresponding correction coefficients;

[0068] High-quality signals are obtained based on residual judgment;

[0069] Repeat the above process to obtain high-quality signals from all single linear arrays in the infrared remote sensing image as the single linear array screening signal set;

[0070] A high-quality signal set is formed by filtering all the single-chip linear array signals.

[0071] Correction parameters are obtained by screening signal sets and high-quality signal sets using a single linear array;

[0072] The output signals of all single-chip linear arrays in the infrared remote sensing image are corrected based on the correction parameters to obtain the corrected infrared remote sensing image.

[0073] Example 2

[0074] Ideally, assuming the response of each detector element to the input energy is linear, the output response of the i-th detector element out of n detector elements in the focal plane array at time t can be expressed as:

[0075] x i (t)=k i (t)×y i (t)+b i (t);

[0076] In the formula, y i (t) represents the radiation energy received by the i-th detector unit at time t, x i (t) represents the output code value of detector unit i, k i(t) represents the response sensitivity corresponding to detector element i, i.e., the gain coefficient (which is independent of the incident parameters) and b. i (t) represents the pixel response offset, i.e., the intercept factor (this coefficient is related to the dark level of the detector element).

[0077] If the responses of all detector elements are consistent, then the k of each detector element i (t) are all the same, and b i (t) is 0. However, in reality, under the same input energy conditions, the k of each detector unit... i (t) and b i The values ​​(t) are not all the same, meaning that the infrared array image exhibits non-uniformity. To correct the inconsistent outputs of pixels to a uniform state, the above formula is transformed into a non-uniformity correction formula for detector unit i, namely:

[0078] y i (t)=G i (t)×x i (t)+O i (t);

[0079] G i (t)=1 / k i (t);

[0080] O i (t)=-b i (t) / k i (t);

[0081] Among them, G i (t) is the gain correction factor for the i-th detector element, O i (t) is the intercept correction factor for the i-th detector element.

[0082] For infrared cameras, the imaging environment needs to be cooled to a fixed temperature to function, and even slight changes in background temperature can alter the intercept correction factor of each pixel. Therefore, the imaging signals of each pixel in a spaceborne infrared camera cannot accumulate and lack statistical characteristics, requiring independent non-uniformity correction for each acquired image track.

[0083] Small-aperture spaceborne infrared cameras possess a variable-temperature uniform blackbody throughout the optical path. During imaging, the code value signal of this variable-temperature uniform blackbody can be acquired. Based on the aforementioned formula, the non-uniformity correction coefficient for the corresponding pixel can be calculated. This calibration-based method is widely used for non-uniformity correction in spaceborne infrared camera images. However, wide-field-of-view, high-resolution pushbroom cameras lack a variable-temperature blackbody throughout the optical path, making calibration methods unsuitable. Therefore, single-scene scene correction methods are required to correct image non-uniformity.

[0084] Based on this, this invention discloses a relative radiometric correction method for wide-swath mid-wave infrared remote sensing images, including:

[0085] Acquire the infrared remote sensing image to be processed.

[0086] Preferably, the infrared remote sensing image is stitched together from sub-images scanned by multiple monolithic linear arrays. Each monolithic linear array consists of multiple detector units, and the output signals of all detector units in each monolithic linear array together form the corresponding sub-image.

[0087] Preferably, in this embodiment, the infrared remote sensing image to be processed is a single-scene image with a wide field of view and high resolution that can be arbitrarily imaged.

[0088] The corresponding correction coefficients are determined based on the two adjacent detector units in each monolithic linear array of the infrared remote sensing image.

[0089] Preferably, the method for determining the correction coefficient is as follows:

[0090] Based on the laboratory calibration strategy of mid-wave infrared camera, the correction coefficients corresponding to the detector unit are determined by using blackbody radiation source.

[0091] The correction factors include the gain factor and the intercept factor.

[0092] The residual is obtained based on the output signals of the two detector units and the corresponding correction coefficients.

[0093] Preferably, the residual is calculated by sequentially acquiring the output signals of two adjacent detector units and the corresponding correction coefficients of all detector units in the monolithic linear array. For example, if the monolithic linear array includes 7 detector units {a1,a2,a3,a4,a5,a6,a7}, then the residual between adjacent detector units a1 and a2 is calculated first, then the residual between a2 and a3 is calculated, and so on.

[0094] The preferred method for obtaining the residual is as follows:

[0095] The residual detH is obtained based on the output signals of the two adjacent detector units and their corresponding correction coefficients:

[0096] detH=(k i ×Y i -k j ×Y j )-(b j -b i );

[0097] Where, k i k represents the gain coefficient of the i-th detector element. jY represents the gain coefficient of the j-th detector element, where the i-th detector element is adjacent to the j-th detector element. i Y represents the output signal of the i-th detector unit. j b represents the output signal of the j-th detector unit. i b represents the intercept factor of the i-th detector element. j This represents the intercept factor of the j-th detector element.

[0098] Preferably, the output signal Y of the i-th detector unit i for:

[0099]

[0100] Among them, DN i,M This represents the DN value output by the i-th detector unit in the M-th row.

[0101] Preferably, the output signal Y of the j-th detector unit j for:

[0102]

[0103] Among them, DN j,M This represents the DN value output by the j-th detector unit in the M-th row.

[0104] Preferably, in the ideal situation where the camera imaging state is completely consistent with the laboratory calibration test state:

[0105] but: At this time, let:

[0106]

[0107] High-quality signals are obtained based on residual judgment.

[0108] Preferably, high-quality signals are obtained based on residual judgment, specifically including:

[0109] Determine whether the absolute value of the residual is less than the threshold;

[0110] If so, the output signals of the two adjacent detector units will be used as high-quality signals;

[0111] Otherwise, continue judging the residuals of other two adjacent detector units in sequence until all detector units in the current monolithic linear array have been judged, and all high-quality signals in the current monolithic linear array are obtained.

[0112] Preferably, for example, a single linear array includes 7 detector units {a1, a2, a3, a4, a5, a6, a7}. First, the residual is calculated and judged based on the adjacent detector units a1 and a2. If the residual is less than the threshold, the output signals of detector units a1 and a2 are both regarded as high-quality signals. Then, the residual is calculated and judged based on the adjacent detector units a3 and a4, and so on. If the residual of detector units a1 and a2 is greater than or equal to the threshold, the screening requirement is not met. The residual is calculated and judged based on the adjacent detector units a2 and a3, and so on. The above judgment process is repeated until all detector units in the current single linear array are judged, and all high-quality signals in the current single linear array are obtained.

[0113] Preferably, this algorithm utilizes the radiation characteristics of the camera system as the basis for sample control in the scene method. After selecting high-quality samples, the correction parameters for the non-uniformity of each detector unit are calculated. During the calculation process, the algorithm maintains the gain coefficient k of detector unit i. i Its stability is minimally affected by differences in samples within the imaging scene, and the algorithm exhibits strong robustness.

[0114] Repeat the above process to obtain high-quality signals from all single-chip linear arrays in the infrared remote sensing image as the single-chip linear array screening signal set.

[0115] Preferably, the high-quality signals obtained by screening each single linear array in the infrared remote sensing image are used as the corresponding single linear array screening signal set.

[0116] A high-quality signal set is formed by filtering all the single-chip linear array signals.

[0117] Preferably, a high-quality signal set is formed by combining high-quality signals from all the single-chip linear array screening signal sets.

[0118] Correction parameters are obtained by screening signal sets and high-quality signal sets using a single linear array.

[0119] Preferably, the method for obtaining the calibration parameters is as follows:

[0120] Based on the selection of all high-quality signals in the signal set using a single linear array, the mean and variance of the single linear array are used together as the first parameter.

[0121] The population mean and population variance are obtained from all high-quality signals in the high-quality signal set and used as the second parameter.

[0122] The correction parameters are composed of the first parameter and the second parameter.

[0123] Preferably, the average value u of a single linear array i and the variance δ of a single linear array i They are respectively:

[0124]

[0125] Among them, Y i,j This indicates the high-quality signal selected from the signal set of the single linear array, where i represents the sequence number of the single linear array, j represents the sequence number of the detector unit, and M represents the number of imaging output rows.

[0126] Preferably, the overall mean u r and population variance δ r They are respectively:

[0127]

[0128] Where N represents the number of single linear arrays.

[0129] The output signals of all single-chip linear arrays in the infrared remote sensing image are corrected based on the correction parameters to obtain the corrected infrared remote sensing image.

[0130] The preferred method for acquiring calibrated infrared remote sensing images is as follows:

[0131] Based on the correction parameters, the output signals of all single linear arrays in the infrared remote sensing image are corrected according to the corresponding single linear array to obtain the corrected single linear array output code value.

[0132] The corrected infrared remote sensing image is obtained based on the output code values ​​of all the single-chip linear arrays.

[0133] Preferably, the output code value of a single linear array is as follows:

[0134]

[0135] Among them, Y i,j ' indicates the corrected output code value of the monolithic linear array.

[0136] Example 3

[0137] Experiments verify the superiority of the method of this invention:

[0138] The outdoor imaging data from a mid-wave infrared camera was used as the data source. The main parameters of the camera are shown in Table 1.

[0139] Table 1 Camera Parameter List

[0140]

[0141] The photoelectric response curves of the 6-detector camera system acquired from a uniform blackbody at different temperatures are shown below. Figure 2 As shown. From Figure 2As can be seen, the photoelectric response of the six detectors in this camera system is essentially linear within its operating range. Based on this response curve, the correction coefficient (k) for each detector element i in each linear array can be calculated. i ,b i ).

[0142] The mid-infrared band is an important target detection band, enabling all-day imaging. At night, it acquires the target's temperature radiation information, while during the day, it acquires not only the target's temperature radiation information but also its reflection and scattering information, as well as atmospheric scattering information. Algorithm analysis is performed using one image from both daytime and nighttime.

[0143] like Figures 3-4 As shown, the images are the original daytime and nighttime images, respectively. The images contain buildings, sky background, cirrus clouds, and other targets. The vertical direction represents the detector pixel arrangement, and the horizontal direction represents the pushbroom direction. It can be seen that the cloud layering in the daytime mid-infrared image is richer and brighter, while the nighttime sky background is cleaner. The image non-uniformity was corrected using both the traditional moment matching correction method and the correction method of this invention, and the correction results are shown below. Figures 5-8 As shown, the original signal output image exhibits strong non-uniformity, making it difficult to distinguish target information without processing. Furthermore, the response of a single 1024-element detector unit shows a characteristic of strong response at the center and weaker response towards the edges. After non-uniformity correction, these effects of a single detector unit are largely eliminated. The correction results show that the traditional moment matching method results in uneven grayscale distribution of buildings because the calculation of the non-uniformity correction coefficient for each detector unit is easily interfered with by the detected sample signal. When excessively bright or dark targets are introduced into the sample, the calculation results show significant deviations, thus affecting the correction outcome. After correction using the method of this invention, the target is clearer and the grayscale distribution is more uniform, eliminating non-uniform bands in the image.

[0144] The correction results were evaluated using two metrics: the inverse deviation coefficient (ICV) and the non-uniformity coefficient (MUC).

[0145] Measurement Standard 1: Inverse Deviation Coefficient

[0146] The inverse deviation coefficient is used to assess the flatness of a specified region in an image; a larger value indicates better flatness. Its expression is:

[0147]

[0148] In the formula, R m R refers to the mean of a specified region in the corrected image. d It refers to the mean square error of the corresponding region in the corrected image.

[0149] Measurement Standard Two:

[0150] The non-uniformity correction result of an image is evaluated using the national standard definition of MUC. The smaller the MUC calculation result, the higher the correction accuracy.

[0151] Its expression is:

[0152]

[0153] Among them, y i,j Let i be the output code value of detector unit i in the j-th frame. It is the average value of all pixels in an M×N image region.

[0154] Using the above measurement standards, a region with a clean nighttime sky background of 2000×1900 pixels was selected as the evaluation sample. The two evaluation indicators for the sample were calculated, as shown in Table 2:

[0155] Table 2 Calculation results of different evaluation indicators

[0156]

[0157] Based on the analysis of the experimental results, the following conclusions can be drawn:

[0158] (1) The ICV index of the traditional moment matching algorithm is 3.27 times that of the original image. The ICV index of the correction method of this invention is 10.14 times that of the original image, which is 6.86 times higher than that of the traditional moment matching algorithm.

[0159] (2) For the MUC index, the traditional correction algorithm calculates 13.5%, while the correction method of this invention calculates 4.4%, which is 9.13% lower than the traditional algorithm.

[0160] The correction method of this invention, by incorporating the camera's own radiation constraints, reduces its reliance on statistical samples compared to traditional correction algorithms, resulting in stronger robustness and easier engineering implementation. This method has been successfully applied to on-orbit image preprocessing for spaceborne cameras. Compared to terrestrial images, on-orbit images exhibit better layering and richer grayscale distribution information. This invention's correction method overcomes the design limitations of high-resolution, wide-field-of-view infrared cameras.

[0161] This invention addresses the characteristics of large field-of-view pushbroom infrared cameras by proposing a real-time non-uniformity correction algorithm for single-image scenes based on the camera's own radiation characteristics. This overcomes the design limitations of large field-of-view, high-resolution infrared cameras, significantly improving the non-uniformity correction accuracy of the corrected image. Furthermore, this algorithm completes the correction of a single image of 30,000 pixels * 30,000 rows in approximately one minute.

[0162] Example 4

[0163] like Figure 9As shown, a relative radiometric correction device for a wide-swath mid-wave infrared remote sensing image includes: an image acquisition module, a correction coefficient acquisition module, a high-quality signal determination module, a signal set acquisition module, a correction parameter acquisition module, and an image correction module.

[0164] The image acquisition module is used to acquire infrared remote sensing images to be processed;

[0165] The correction coefficient acquisition module is used to determine the corresponding correction coefficient based on two adjacent detector units in each monolithic linear array in the infrared remote sensing image.

[0166] A high-quality signal determination module is used to obtain the residual based on the output signals of the two detector units and the corresponding correction coefficients; and to determine the high-quality signal based on the residual.

[0167] The signal set acquisition module is used to repeat the above process to obtain high-quality signals from all single-chip linear arrays in the infrared remote sensing image as a single-chip linear array screening signal set; and to form a high-quality signal set based on all the single-chip linear array screening signal sets.

[0168] The calibration parameter acquisition module is used to obtain calibration parameters based on the filtered signal set and high-quality signal set of the single-chip linear array.

[0169] The image correction module is used to correct the output signals of all single-chip linear arrays in the infrared remote sensing image based on correction parameters, so as to obtain a corrected infrared remote sensing image.

[0170] Preferably, the functional implementation process of each functional module in this embodiment corresponds one-to-one with the above-described method, and will not be described in detail here.

[0171] Example 5

[0172] Based on the same inventive concept, the present invention also provides a computer device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0173] Memory, used to store computer programs;

[0174] When the processor executes a program stored in the memory, it is able to implement a relative radiometric correction method for a wide-swath mid-wave infrared remote sensing image, as in Embodiment 1 or 2.

[0175] The electronic device may include a processor, a communications interface, a memory, and a communication bus, wherein the processor, communications interface, and memory communicate with each other via the communication bus. The processor can invoke logical instructions in the memory to execute a relative radiometric correction method for a wide-swath mid-wave infrared remote sensing image, as described in Embodiment 1 or 2.

[0176] Furthermore, when the logical instructions in the aforementioned memory can be implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0177] As can be seen from the above technical solution, compared with the prior art, this invention discloses a relative radiometric correction method and apparatus for wide-swath mid-wave infrared remote sensing images. This invention is based on the imaging mechanism of mid-wave infrared detectors and utilizes the radiometric characteristics of the camera system as the sample control basis in the scene method. After selecting reasonable high-quality samples, the non-uniformity correction coefficients of each detector unit are calculated. During the calculation process, this apparatus maintains the stability of the detector unit gain coefficients and is less affected by statistical differences caused by samples in the imaging scene, demonstrating strong algorithm robustness.

[0178] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0179] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for relative radiometric correction of wide-swath mid-wave infrared remote sensing images, characterized in that, include: Acquire the infrared remote sensing image to be processed; The corresponding correction coefficients are determined based on the two adjacent detector units in each monolithic linear array of the infrared remote sensing image. The method for determining the correction coefficient is as follows: Based on the laboratory calibration strategy of the mid-wave infrared camera, the correction coefficients corresponding to the detector unit are determined by using a blackbody radiation source. The correction coefficients include: gain coefficient and intercept factor; The residual is obtained based on the output signals of the two detector units and the corresponding correction coefficients; A high-quality signal is obtained based on the residual judgment; Repeat the above process to obtain the high-quality signals from all single linear arrays in the infrared remote sensing image as the single linear array screening signal set; A high-quality signal set is formed by filtering all the aforementioned single-chip linear array signals. Correction parameters are obtained based on the single-chip linear array filtered signal set and the high-quality signal set; The method for obtaining the correction parameters is as follows: Based on all high-quality signals in the single-chip linear array screening signal set, the mean and variance of the single-chip linear array are used together as the first parameter. The overall mean and overall variance of all high-quality signals in the high-quality signal set are used together as the second parameter. The correction parameters are composed of the first parameter and the second parameter together; Based on the correction parameters, the output signals of all the single linear arrays in the infrared remote sensing image are corrected to obtain a corrected infrared remote sensing image. The method for acquiring the corrected infrared remote sensing image is as follows: Based on the correction parameters, the output signals of all the single-chip linear arrays in the infrared remote sensing image are corrected according to the corresponding single-chip linear arrays to obtain the corrected single-chip linear array output code value. The corrected infrared remote sensing image is obtained based on all the output code values ​​of the single-chip linear array; The specific output code value of the single-chip linear array is as follows: Among them, Y i,j ' represents the corrected output code value of the monolithic linear array, u i δ represents the mean of a single linear array. i Y represents the variance of a single linear array. i,j This indicates the high-quality signal selected from the signal set by a single linear array, u r δ represents the population mean. r The total variance is represented by i, the serial number of the single linear array is represented by j, the serial number of the detector unit is represented by M, the number of imaging output rows is represented by N, and the number of single linear arrays is represented by N.

2. The relative radiometric correction method for a wide-swath mid-wave infrared remote sensing image according to claim 1, characterized in that, The method for obtaining the residual is as follows: The residual detH is obtained based on the output signals of the two adjacent detector units and the corresponding correction coefficients: detH=(k i ×Y i -k j ×Y j )-(b j -b i ); Where, k i Let k represent the gain coefficient of the i-th detector element. j Y represents the gain coefficient of the j-th detector element, where the i-th detector element is adjacent to the j-th detector element. i Y represents the output signal of the i-th detector unit. j b represents the output signal of the j-th detector unit. i b represents the intercept factor of the i-th detector element. j This represents the intercept factor of the j-th detector element.

3. The relative radiometric correction method for a wide-swath mid-wave infrared remote sensing image according to claim 1, characterized in that, A high-quality signal is obtained based on the residual judgment, specifically including: Determine whether the absolute value of the residual is less than a threshold; If so, the output signals of the two adjacent detector units are taken as the high-quality signal; Otherwise, continue to judge the residuals of other two adjacent detector units in sequence until all detector units in the current monolithic linear array have been judged, and all the high-quality signals in the current monolithic linear array are obtained.

4. The relative radiometric correction method for a wide-swath mid-wave infrared remote sensing image according to claim 1, characterized in that, The mean value of the single linear array u i and the variance δ of the single linear array i They are respectively: Among them, Y i,j This indicates the high-quality signal selected from the signal set by the single linear array, where i represents the sequence number of the single linear array, j represents the sequence number of the detector unit, and M represents the number of imaging output rows.

5. The relative radiometric correction method for a wide-swath mid-wave infrared remote sensing image according to claim 4, characterized in that, The overall mean u r and the total variance δ r They are respectively: Where N represents the number of single linear arrays.

6. A relative radiometric correction device for a wide-swath mid-wave infrared remote sensing image, applied to the relative radiometric correction method for a wide-swath mid-wave infrared remote sensing image as described in any one of claims 1-5, characterized in that, include: The system includes an image acquisition module, a correction coefficient acquisition module, a high-quality signal determination module, a signal set acquisition module, a correction parameter acquisition module, and an image correction module. The image acquisition module is used to acquire the infrared remote sensing image to be processed; The correction coefficient acquisition module is used to determine the corresponding correction coefficient based on two adjacent detector units in each single linear array of the infrared remote sensing image. The high-quality signal determination module is used to obtain the residual based on the output signals of the two detector units and the corresponding correction coefficients; and to determine the high-quality signal based on the residual. The signal set acquisition module is used to repeat the above process to obtain the high-quality signals from all single-chip linear arrays in the infrared remote sensing image as a single-chip linear array screening signal set; and to form a high-quality signal set based on all the single-chip linear array screening signal sets. The correction parameter acquisition module is used to obtain correction parameters based on the single-chip linear array filtered signal set and the high-quality signal set. The image correction module is used to correct the output signals of all the single-chip linear arrays in the infrared remote sensing image based on the correction parameters, so as to obtain a corrected infrared remote sensing image.

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