Brightness homogenization method and system for pneumatic thermal radiation effect image sequence

Abstract

The invention belongs to the technical field of digital image processing, and discloses a pneumatic thermal radiation effect image sequence brightness homogenization method and system, and the method comprises the steps: constructing a weight function of a bias field fitting coefficient vector based on the pneumatic thermal radiation effect bias field fitting coefficient vector of each frame of degraded image in a degraded image sequence; constructing a bias field sparse vector of each frame of degraded image by using the weight function; fitting a bias field of each frame of degraded image; and subtracting the corresponding fitted bias field from each frame of degraded image to obtain each frame of corrected image so as to realize brightness homogenization of the degraded image sequence. Furthermore, a fitting function based on image sequence gray level distribution of each frame of corrected image is constructed, the fitting function is used for replacing the mean value of the corresponding corrected image, an updated corrected image is obtained, and further uniformization of the degraded image sequence brightness is achieved. According to the invention, the brightness of the pneumatic thermal radiation effect image sequence can be homogenized.

Description

Technical Field

[0001] The present invention belongs to the technical field of digital image processing, and more specifically, relates to a method and system for uniformizing brightness of an aerodynamic thermal radiation effect image sequence. Background Art

[0002] When an aircraft equipped with an imaging system flies in the atmosphere, the optical hood heats up due to friction with the high-speed oncoming flow, inducing an aerodynamic thermal radiation effect similar to a "halo" on the image plane, degrading the signal-to-noise ratio of the target image.

[0003] Existing correction technologies focus on statistical modeling of the bias field degradation characteristics of aerodynamic thermal radiation effects, and use a variety of polynomial fitting methods to estimate the bias field surface shape to correct the degraded image. These methods have a good correction effect on single-frame images, but the correction effect on image sequences is limited, which is specifically manifested in the screen flicker phenomenon of the corrected image sequence, that is, the brightness of the corrected image sequence is uneven. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a method and system for uniforming the brightness of an aerodynamic thermal radiation effect image sequence, the purpose of which is to uniformly adjust the brightness of an aerodynamic thermal radiation effect image sequence.

[0005] To achieve the above object, according to a first aspect of the present invention, a method for uniformizing brightness of an aerodynamic thermal radiation effect image sequence is provided, comprising:

[0006] Based on the bias field fitting coefficient vector of the aerodynamic thermal radiation effect of each frame of the degraded image in the degraded image sequence, a weight function of the bias field fitting coefficient vector is constructed; wherein the weight function is used to associate the bias field fitting coefficient vectors of the n-frame degraded image sequence;

[0007] The weight function is used to construct the bias field sparse vector of each frame of degraded image:

[0008]

[0009] In the formula, a i ' represents the i-th frame degraded image X i The bias field sparse vector, a j represents the bias field fitting coefficient vector of the j-th frame degraded image, k j represents the weight function of the bias field fitting coefficient vector of the j-th frame degraded image;

[0010] Fit the bias field of each frame of degraded image: B i =Wa i ', where B i represents the i-th frame degraded image X iThe bias field W is a dictionary used to obtain the bias field fitting coefficient vector;

[0011] Each frame of the corrected image is obtained by subtracting the corresponding fitted bias field from each frame of the degraded image, so as to achieve brightness uniformity for the degraded image sequence.

[0012] Furthermore, the weight function is:

[0013]

[0014] Among them, a i represents the i-th frame degraded image X i The bias field fitting coefficient vector, k i Represents the bias field fitting coefficient vector a i The weight function of , 1 represents the L1 norm.

[0015] Furthermore, obtaining the aerodynamic thermal radiation effect bias field fitting coefficient vector of each frame of the degraded image in the degraded image sequence includes:

[0016] The aerodynamic thermal radiation effect field polynomial fitting method is adopted to fit the bias field of each frame of the degraded image in the degraded image sequence, so as to obtain the aerodynamic thermal radiation effect bias field fitting coefficient vector of each frame of the degraded image.

[0017] Furthermore, after obtaining the corrected image, the method further includes:

[0018] Construct a fitting function based on the grayscale distribution of the image sequence for each frame of the corrected image:

[0019]

[0020]

[0021] In the formula, g i Represents the corrected image Z of the i-th frame i The fitting function based on the grayscale distribution of the image sequence; k t represents the fitting coefficient; Z m (p,q) is the corrected image Z m The gray value at (p,q), Z t (p,q) is the corrected image Z t The grayscale value at (p, q), w and h represent the width and height of each frame of the corrected image respectively;

[0022] The fitting function is used to replace the mean value of the corresponding corrected image to obtain an updated corrected image, thereby further homogenizing the brightness of the degraded image sequence.

[0023] According to a second aspect of the present invention, there is provided a system for uniformizing brightness of an aerodynamic thermal radiation effect image sequence, comprising:

[0024] A weight function construction module, used to construct a weight function of the bias field fitting coefficient vector based on the aerodynamic thermal radiation effect bias field fitting coefficient vector of each frame of the degraded image sequence; wherein the weight function is used to associate the bias field fitting coefficient vector of the n-frame degraded image sequence;

[0025] The bias field sparse vector construction module is used to construct the bias field sparse vector of each frame of degraded image using the weight function:

[0026]

[0027] In the formula, a i ' represents the i-th frame degraded image X i The bias field sparse vector, a j represents the bias field fitting coefficient vector of the j-th frame degraded image, k j represents the weight function of the bias field fitting coefficient vector of the j-th frame degraded image;

[0028] Bias field fitting module, used to fit the bias field of each frame of degraded image: B i =Wa i ', where B i represents the i-th frame degraded image X i The bias field W is a dictionary used to obtain the bias field fitting coefficient vector;

[0029] The first brightness uniformization module is used to subtract the corresponding fitted bias field from each frame of the degraded image to obtain each frame of the corrected image, so as to achieve brightness uniformity for the degraded image sequence.

[0030] Furthermore, the weight function is:

[0031]

[0032] Among them, a i represents the i-th frame degraded image X i The bias field fitting coefficient vector, k i Represents the bias field fitting coefficient vector a i The weight function of , 1 represents the L1 norm.

[0033] Furthermore, it also includes:

[0034] The fitting function building module is used to build a fitting function based on the grayscale distribution of the image sequence for each frame of the correction image:

[0035]

[0036]

[0037] In the formula, g i Represents the corrected image Z of the i-th frame i The fitting function based on the grayscale distribution of the image sequence; k t represents the fitting coefficient; Z m (p,q) is the corrected image Z m The gray value at (p,q), Z t (p,q) is the corrected image Z t The grayscale value at (p, q), w and h represent the width and height of each frame of the corrected image respectively;

[0038] The second brightness uniformization module is used to replace the mean value of the corresponding corrected image with the fitting function to obtain an updated corrected image, thereby further uniformizing the brightness of the degraded image sequence.

[0039] According to a third aspect of the present invention, there is provided an electronic device comprising a computer-readable storage medium and a processor;

[0040] The computer-readable storage medium is used to store executable instructions;

[0041] The processor is used to read the executable instructions stored in the computer-readable storage medium to execute the method for uniformizing brightness of aerodynamic thermal radiation effect image sequence described in any one of the first aspects.

[0042] According to a fourth aspect of the present invention, there is provided a computer-readable storage medium having a computer program stored thereon, wherein when the program is executed by a processor, the method for uniformizing brightness of an aerodynamic thermal radiation effect image sequence as described in any one of the first aspects is implemented.

[0043] According to a fifth aspect of the present invention, there is provided a computer program product, comprising a computer program, which, when executed on a computer, enables the computer to execute the method for uniformizing brightness of an aerodynamic thermal radiation effect image sequence as described in any one of the first aspects.

[0044] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0045] (1) After analysis, the present invention finds that one of the reasons for the uneven brightness of the corrected image sequence is the sudden change of the bias field surface fitted in adjacent frames in the image sequence. That is, the existing polynomial fitting method for the bias field of the aerodynamic thermal radiation effect only imposes a smooth constraint on the gradient of a single frame image, and does not consider the smooth change of the image time series, resulting in a large change in the estimated bias field time series grayscale. In addition, the polynomial fitting method represents the bias field through a coefficient vector and a dictionary, but the sparse coefficient vector is greatly affected by factors such as noise, resulting in an unstable estimated bias field (the noise points in the coefficient vector cause inaccurate surface fitting). Based on this discovery, the present invention proposes a weight function for associating the bias field fitting coefficient vectors of multiple-frame degraded image sequences, and constructs a bias field sparse vector for each frame of degraded image based on the weight function to add a global constraint to the bias field fitting coefficient vector of the aerodynamic thermal radiation effect (the bias field sparse vector is associated with the bias field fitting coefficient vectors of consecutive n frames of degraded images starting from the current frame of degraded image), so as to avoid sudden changes in the bias field surfaces of adjacent frames due to noise points in the coefficient vector, avoid obvious jumps in the bias field between adjacent frames, and ensure the grayscale stability of the reconstructed field sequence.

[0046] (2) As a preference, the weight function of the bias field fitting coefficient vector constructed in the present invention utilizes the characteristic of the L1 norm to promote sparse solutions and reduce the influence of noise and redundant information; and the numerator of the weight function is the characteristic of the i-th frame degraded image X i The bias field fitting coefficient vector a i The L1 norm of retains the key field information. At the same time, the denominator globally associates the multi-frame bias field fitting coefficient vector, avoiding obvious jumps in the bias field between similar frames.

[0047] (3) Further, after analysis, the present invention found that the reason for the uneven brightness of the corrected image sequence also includes the uneven grayscale transition of the corrected image sequence, that is, the existing polynomial fitting method for the aerodynamic thermal radiation effect bias field only considers the removal of the infrared thermal radiation effect field, and the corrected image sequence is difficult to maintain consistent brightness on a global scale, and the grayscale retention is poor with the original image sequence. Based on this discovery, the present invention proposes to associate the grayscale mean of the corrected image sequence. Specifically, a grayscale mean fitting function based on the grayscale distribution of the image sequence is constructed to replace the mean of the corrected image sequence and eliminate the grayscale fluctuations in the corrected image sequence. The image sequence grayscale mean fitting function models the grayscale information of the consecutive n frames of corrected images starting from the current frame, smoothes the grayscale transition, and utilizes the global grayscale distribution characteristics of the image sequence to keep the brightness of the corrected image sequence consistent on a global scale, thereby improving the stability of the grayscale distribution of the corrected image sequence.

[0048] In summary, the present invention constructs a weight function based on the polynomial fitting coefficient of the aerodynamic thermal radiation effect field to stably fit the bias field surface to homogenize the grayscale of the image sequence; further, a grayscale mean fitting function based on the image grayscale distribution is constructed to smoothly correct the grayscale transition of the image sequence, so that the corrected image sequence can maintain consistent brightness in a global range. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 Schematic diagram of a method for uniforming brightness of an aerodynamic thermal radiation effect image sequence in an embodiment of the present invention.

[0050] Figure 2 The figure shows the comparison of the grayscale mean preservation effect of the infrared image in the embodiment of the present invention.

[0051] Figure 3 The following is a comparison of the visualization effects of using the brightness uniformization technology and not using the brightness uniformization technology in the embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0053] Example 1

[0054] like Figure 1 As shown, an embodiment of the present invention provides a method for uniformizing brightness of an aerodynamic thermal radiation effect image sequence, which mainly includes:

[0055] S1, constructing a weight function of the bias field fitting coefficient vector based on the aerodynamic thermal radiation effect bias field fitting coefficient vector of each frame of the degraded image sequence; the weight function is used to associate the bias field fitting coefficient vector of the n-frame degraded image sequence;

[0056] S2. Use the weight function to construct the bias field sparse vector of each frame of degraded image:

[0057]

[0058] In the formula, a i ' represents the i-th frame degraded image X i The bias field sparse vector, a j represents the bias field fitting coefficient vector of the j-th frame degraded image, k j represents the weight function of the bias field fitting coefficient vector of the j-th frame degraded image; n is the number of fused frames;

[0059] S3. Fitting the bias field of each frame of degraded image: B i =Wa i ', where B i represents the i-th frame degraded image X i The bias field of , W is the dictionary used to obtain the above bias field fitting coefficient vector;

[0060] S4. Subtract the corresponding fitted bias field from each frame of degraded image to obtain each frame of corrected image: Z i =X i -B i , Z i represents the i-th frame corrected image to achieve brightness uniformity for the degraded image sequence.

[0061] As a preferred implementation, in S1, obtaining the aerodynamic thermal radiation effect bias field fitting coefficient vector of each frame of degraded image includes:

[0062] The aerodynamic thermal radiation effect field polynomial fitting method is used to fit the bias field of each frame of degraded image in the degraded image sequence, and the aerodynamic thermal radiation effect bias field fitting coefficient vector of each frame of degraded image is obtained.

[0063] As a preferred implementation, in S1, the weight function of the bias field fitting coefficient vector constructed is:

[0064]

[0065] Among them, a i represents the i-th frame degraded image X i The bias field fitting coefficient vector, k i Represents the bias field fitting coefficient vector a i The weight function is , 1 represents the L1 norm, and n is the number of fused frames.

[0066] In other embodiments, other weight functions of the bias field fitting coefficient vector may be selected. For example, corresponding coefficients may be added to the above weight function formula according to actual needs, as long as the weight function can be associated with the bias field fitting coefficient vector of the n-frame degraded image sequence.

[0067] After analysis, the present invention finds that one of the reasons for the uneven brightness of the corrected image sequence is the sudden change of the bias field surface fitted in adjacent frames in the image sequence, that is, the existing polynomial fitting method of the bias field of the aerodynamic thermal radiation effect only imposes a smooth constraint on the gradient of a single frame image, and does not consider the smooth change of the image time series, resulting in a large change in the estimated bias field time series grayscale, and the polynomial fitting method represents the bias field through a coefficient vector and a dictionary, but the sparse coefficient vector is greatly affected by factors such as noise, resulting in instability of the estimated bias field (the noise points in the coefficient vector cause inaccurate surface fitting). Based on this discovery, the present invention proposes a weight function for associating the bias field fitting coefficient vectors of multiple-frame degraded image sequences, and constructs a bias field sparse vector for each frame of degraded image based on the weight function to add a global constraint to the bias field fitting coefficient vector of the aerodynamic thermal radiation effect (the bias field sparse vector is associated with the bias field fitting coefficient vectors of consecutive n frames of degraded images starting from the current frame of degraded image), so as to avoid sudden changes in the bias field surfaces of adjacent frames due to noise points in the coefficient vector, avoid obvious jumps in the bias field between adjacent frames, and ensure the grayscale stability of the reconstructed field sequence.

[0068] Preferably, the weight function of the bias field fitting coefficient vector constructed in the present invention utilizes the characteristic of L1 norm to promote sparse solution and reduce the influence of noise and redundant information; and the numerator of the weight function is the characteristic of the i-th frame degraded image X i The bias field fitting coefficient vector a i The L1 norm of retains the key field information. At the same time, the denominator globally associates the multi-frame bias field fitting coefficient vector, avoiding obvious jumps in the bias field between similar frames.

[0069] As a further design of the present invention, step S4 further includes:

[0070] S5. Construct a fitting function based on the grayscale distribution of the image sequence for each frame of the corrected image:

[0071]

[0072]

[0073] In the formula, g i Represents the corrected image Z of the i-th frame i The fitting function based on the grayscale distribution of the image sequence; k t represents the fitting coefficient; Z m (p,q) is the corrected image Z m The gray value at (p,q), Z t (p,q) is the corrected image Z t The grayscale value at (p, q), w and h represent the width and height of each frame of the corrected image, respectively.

[0074] S6. Replace the mean of the corresponding corrected image with the fitting function to obtain an updated corrected image to achieve further brightness uniformity:

[0075] Z stable_i =Z i -mean(Z i )+g i

[0076] In the formula, Z stable_i represents the updated corrected image of the i-th frame, i.e., the corrected image with further uniform brightness; mean(Z i ) is the grayscale mean of the rectified image of the i-th frame.

[0077] After analysis, the present invention found that the reason for the uneven brightness of the corrected image sequence also includes the uneven grayscale transition of the corrected image sequence, that is, the existing polynomial fitting method of the aerodynamic thermal radiation effect bias field only considers the removal of the infrared thermal radiation effect field, and the corrected image sequence is difficult to maintain consistent brightness in a global range, and the grayscale retention is poor with the original image sequence. Based on this discovery, the present invention proposes to associate the grayscale mean of the corrected image sequence. Specifically, a grayscale mean fitting function based on the grayscale distribution of the image sequence is constructed to replace the mean of the corrected image sequence and eliminate the grayscale fluctuations in the corrected image sequence. The image sequence grayscale mean fitting function models the grayscale information of the continuous n frames of corrected images starting from the current frame, smoothes the grayscale transition, and utilizes the global grayscale distribution characteristics of the image sequence to keep the brightness of the corrected image sequence consistent in a global range, thereby improving the stability of the grayscale distribution of the corrected image sequence.

[0078] The present invention will be further described below in conjunction with the embodiments. Figure 2 As shown, it is a grayscale change of the image itself, a grayscale mean comparison simulation diagram of the frame sequence obtained without using the method of the present invention and using the method of the present invention, and Figure 3 The comparison of the visualization effects of using the brightness equalization technology and not using the brightness equalization technology is shown. It can be seen from the figure that the use of the present invention can reduce the grayscale mean mutation in the image sequence, effectively stabilize the thermal radiation bias field, and maintain good grayscale with the original image.

[0079] The present invention provides a technology for uniform brightness of an image sequence of aerodynamic thermal radiation effect. The overall concept is to conduct an in-depth analysis of the mechanism of the generation of related problems. Based on the analysis results, a global constraint is added to the polynomial fitting coefficient vector of the aerodynamic thermal radiation effect to avoid the sudden change of the bias field surface of adjacent frames due to noise points in the coefficient vector, stabilize the estimation of the bias field sequence, and uniformize the grayscale of the image sequence. Furthermore, the grayscale of the corrected image sequence is constrained, the grayscale transition is smoothed, and the grayscale of the image sequence finally reconstructed is further uniformed.

[0080] Example 2

[0081] The embodiment of the present invention provides a system for uniformizing brightness of an aerodynamic thermal radiation effect image sequence, comprising:

[0082] A weight function construction module is used to construct a weight function of the bias field fitting coefficient vector based on the aerodynamic thermal radiation effect bias field fitting coefficient vector of each frame of the degraded image sequence; wherein the weight function is used to associate the bias field fitting coefficient vector of the n-frame degraded image sequence;

[0083] The bias field sparse vector construction module is used to construct the bias field sparse vector of each frame of degraded image using the weight function:

[0084]

[0085] In the formula, a i ' represents the i-th frame degraded image X i The bias field sparse vector, a j represents the bias field fitting coefficient vector of the j-th frame degraded image, k j represents the weight function of the bias field fitting coefficient vector of the j-th frame degraded image;

[0086] Bias field fitting module, used to fit the bias field of each frame of degraded image: B i =Wa i ', where B i represents the i-th frame degraded image X i The bias field of , W is the dictionary used to obtain the bias field fitting coefficient vector;

[0087] The first brightness uniformization module is used to subtract the corresponding fitted bias field from each frame of the degraded image to obtain each frame of the corrected image, so as to achieve brightness uniformity for the degraded image sequence.

[0088] As a preferred implementation, the weight function is:

[0089]

[0090] Among them, a i represents the i-th frame degraded image X i The bias field fitting coefficient vector, k i Represents the bias field fitting coefficient vector a i The weight function of , 1 represents the L1 norm.

[0091] As a further design of the present invention, it also includes:

[0092] The fitting function building module is used to build a fitting function based on the grayscale distribution of the image sequence for each frame of the correction image:

[0093]

[0094]

[0095] In the formula, g i Represents the corrected image Z of the i-th frame i The fitting function based on the grayscale distribution of the image sequence; k t represents the fitting coefficient; Z m (p,q) is the corrected image Z m The gray value at (p,q), Z t (p,q) is the corrected image Z t The grayscale value at (p, q), w and h represent the width and height of each frame of the corrected image respectively;

[0096] The second brightness uniformization module is used to replace the mean value of the corresponding corrected image with the fitting function to obtain an updated corrected image, thereby further uniformizing the brightness of the degraded image sequence.

[0097] The specific implementation method of each of the above modules can be found in the corresponding description in Example 1, which will not be repeated here.

[0098] Example 3

[0099] An embodiment of the present invention provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method in the above-mentioned embodiment 1 when executing the computer program.

[0100] The electronic device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The memory may be used to store computer programs and / or modules, and the processor may perform various functions of the electronic device by running or executing computer programs and / or modules stored in the memory, and calling data stored in the memory.

[0101] The relevant technical solutions are the same as above and will not be described in detail here.

[0102] Example 4

[0103] An embodiment of the present invention provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the method in the above-mentioned embodiment 1 are implemented.

[0104] Specifically, the memory may include a high-speed random access memory, and may also include a non-volatile memory, such as a hard disk, an internal memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0105] The relevant technical solutions are the same as above and will not be described again here.

[0106] Example 5

[0107] An embodiment of the present application provides a computer program product, including a computer program. When the computer program is run on a computer, the computer executes the steps of the method in the above-mentioned embodiment 1.

[0108] The relevant technical solutions are the same as above and will not be described again here.

[0109] It will be easily understood by those skilled in the art that 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 and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for uniform brightness of aerodynamic thermal radiation effect image sequence, characterized in that: include: Based on the bias field fitting coefficient vector of the aerodynamic thermal radiation effect of each frame of the degraded image in the degraded image sequence, a weight function of the bias field fitting coefficient vector is constructed; wherein the weight function is used to associate the bias field fitting coefficient vectors of the n-frame degraded image sequence; The weight function is used to construct the bias field sparse vector of each frame of degraded image: In the formula, a i ' represents the i-th frame degraded image X i The bias field sparse vector, a j represents the bias field fitting coefficient vector of the j-th frame degraded image, k j represents the weight function of the bias field fitting coefficient vector of the j-th frame degraded image; Fit the bias field of each frame of degraded image: B i =Wa i ', where B i represents the i-th frame degraded image X i The bias field W is a dictionary used to obtain the bias field fitting coefficient vector; Each frame of the corrected image is obtained by subtracting the corresponding fitted bias field from each frame of the degraded image, so as to achieve brightness uniformity for the degraded image sequence.

2. The method for uniformizing brightness of aerodynamic thermal radiation effect image sequence according to claim 1, characterized in that: The weight function is: Among them, a i represents the i-th frame degraded image X i The bias field fitting coefficient vector, k i Represents the bias field fitting coefficient vector a i The weight function of , || ||1 represents the L1 norm.

3. The method for uniformizing brightness of aerodynamic thermal radiation effect image sequence according to claim 1, characterized in that: Obtaining the aerodynamic thermal radiation effect bias field fitting coefficient vector of each frame of the degraded image in the degraded image sequence, including: The aerodynamic thermal radiation effect field polynomial fitting method is adopted to fit the bias field of each frame of the degraded image in the degraded image sequence, so as to obtain the aerodynamic thermal radiation effect bias field fitting coefficient vector of each frame of the degraded image.

4. The method for uniformizing brightness of aerodynamic thermal radiation effect image sequence according to any one of claims 1 to 3, characterized in that: After obtaining the corrected image, the method further includes: Construct a fitting function based on the grayscale distribution of the image sequence for each frame of the corrected image: In the formula, g i Represents the corrected image Z of the i-th frame i The fitting function based on the grayscale distribution of the image sequence; k t represents the fitting coefficient; Z m (p,q) is the corrected image Z m The gray value at (p,q), Z t (p,q) is the corrected image Z t The grayscale value at (p, q), w and h represent the width and height of each frame of the corrected image respectively; The fitting function is used to replace the mean value of the corresponding corrected image to obtain an updated corrected image, thereby further homogenizing the brightness of the degraded image sequence.

5. A system for uniformizing brightness of an image sequence based on aerodynamic thermal radiation effect, characterized in that: include: A weight function construction module, used to construct a weight function of the bias field fitting coefficient vector based on the aerodynamic thermal radiation effect bias field fitting coefficient vector of each frame of the degraded image sequence; wherein the weight function is used to associate the bias field fitting coefficient vector of the n-frame degraded image sequence; The bias field sparse vector construction module is used to construct the bias field sparse vector of each frame of degraded image using the weight function: In the formula, a i ' represents the i-th frame degraded image X i The bias field sparse vector, a j represents the bias field fitting coefficient vector of the j-th frame degraded image, k j represents the weight function of the bias field fitting coefficient vector of the j-th frame degraded image; Bias field fitting module, used to fit the bias field of each frame of degraded image: B i =Wa i ', where B i represents the i-th frame degraded image X i The bias field W is a dictionary used to obtain the bias field fitting coefficient vector; The first brightness uniformization module is used to subtract the corresponding fitted bias field from each frame of the degraded image to obtain each frame of the corrected image, so as to achieve brightness uniformity for the degraded image sequence.

6. The aerodynamic thermal radiation effect image sequence brightness uniformization system according to claim 5, characterized in that: The weight function is: Among them, a i represents the i-th frame degraded image X i The bias field fitting coefficient vector, k i Represents the bias field fitting coefficient vector a i The weight function of , || ||1 represents the L1 norm.

7. The aerodynamic thermal radiation effect image sequence brightness uniformization system according to claim 5 or 6, characterized in that: Also includes: The fitting function building module is used to build a fitting function based on the grayscale distribution of the image sequence for each frame of the correction image: In the formula, g i Represents the corrected image Z of the i-th frame i The fitting function based on the grayscale distribution of the image sequence; k t represents the fitting coefficient; Z m (p,q) is the corrected image Z m The gray value at (p,q), Z t (p,q) is the corrected image Z t The grayscale value at (p, q), w and h represent the width and height of each frame of the corrected image respectively; The second brightness uniformization module is used to replace the mean value of the corresponding corrected image with the fitting function to obtain an updated corrected image, thereby further uniformizing the brightness of the degraded image sequence.

8. An electronic device, characterized in that: comprising a computer readable storage medium and a processor; The computer-readable storage medium is used to store executable instructions; The processor is used to read the executable instructions stored in the computer-readable storage medium to execute the method for uniformizing brightness of aerodynamic thermal radiation effect image sequence according to any one of claims 1 to 4.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method for uniformizing brightness of an aerodynamic thermal radiation effect image sequence as described in any one of claims 1 to 4 is implemented.

10. A computer program product, characterized in that The invention comprises a computer program, which, when running on a computer, enables the computer to execute the method for uniformizing brightness of aerodynamic thermal radiation effect image sequence as claimed in any one of claims 1 to 4.

Images