Infrared image pot cover effect correction method, system and computer storage medium

Abstract

The present invention relates to a method, system and computer storage medium for correcting pot cover effect of infrared images. The method comprises: collecting pot cover image C0, calculating mean value #imgabs0# of pot cover image C0, performing difference processing between pot cover image C0 and mean value #imgabs1#, and obtaining difference image C; using difference image C as background C; calculating pot cover correction coefficient k0 of current pre-corrected image X by using background C, and updating pot cover correction coefficient k0 to obtain pot cover correction update coefficient k; performing pot cover correction on current pre-corrected image X based on pot cover correction update coefficient k and background C, and obtaining corrected image #imgabs2# after removing pot cover effect. In the present invention, by pre-storing background C, and then using current pre-corrected image X and background C to calculate a correction coefficient k, the correction coefficient k only needs to obtain #imgabs3# and X of each frame of current pre-corrected image X in real time during specific implementation. i,j ,Finally, the corrected image is obtained by calculation, the pot cover removal effect is good and the calculation process is simple.

Description

Technical Field

[0001] The invention relates to the field of infrared image processing, and in particular to an infrared image pot cover effect correction method, system and computer storage medium. Background Art

[0002] Based on the current development level of infrared focal plane technology, the response characteristics between focal plane pixels are inconsistent, so there is a non-uniformity problem in infrared imaging. Since the focal plane detector is placed inside the infrared thermal imager housing, the detector is affected by the heat generated by the infrared thermal imager, resulting in the final infrared image showing a "pot lid" effect with a dark center and bright surroundings. The lens structure of the infrared thermal imager will also aggravate the "pot lid" effect. Since the shutter is inside the infrared thermal imager structure and placed in front of the focal plane detector, the radiation from the shutter does not pass through the lens structure during shutter correction, and the radiation during imaging will be distorted by the lens structure, thus aggravating the "pot lid" phenomenon.

[0003] The existing method for removing pot lids from infrared images is disclosed in the patent publication number CN113421220A. In this prior art, it is not considered that the mean of the ideal background may not be absolutely 0, and the value after the decimal point will affect the result, resulting in an unsatisfactory image correction effect. In addition, the calculation process of the correction coefficient in this prior art is relatively complicated. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method, system and computer storage medium for correcting the pot cover effect of an infrared image, which has a good pot cover removal effect and a simple calculation process.

[0005] The technical solution of the present invention to solve the above technical problem is as follows: a method for correcting the pot cover effect of infrared images, characterized in that it comprises the following steps:

[0006] S1, collect the pot cover image C0, and calculate the mean value of the pot cover image C0 The pot cover image C0 and the mean Performing difference processing to obtain a difference image C; using the difference image C as the background C;

[0007] S2, using the background C to calculate the pot cover correction coefficient k0 of the current pre-corrected image X, and updating the pot cover correction coefficient k0 to obtain a pot cover correction update coefficient k;

[0008] S3, performing pot cover correction on the current pre-corrected image X based on the pot cover correction update coefficient k and the background C, to obtain a corrected image after removing the pot cover effect

[0009] Based on the above infrared image pot cover effect correction method, the present invention also provides an infrared image pot cover effect correction system.

[0010] An infrared image pot cover effect correction system includes the following modules:

[0011] The background generation module is used to collect the pot cover image C0 and calculate the mean value of the pot cover image C0. The pot cover image C0 and the mean Performing difference processing to obtain a difference image C; using the difference image C as the background C;

[0012] A coefficient calculation module, which is used to calculate a pot cover correction coefficient k0 of the current pre-corrected image X using the background C, and update the pot cover correction coefficient k0 to obtain a pot cover correction update coefficient k;

[0013] A correction module is used to perform pot cover correction on the current pre-corrected image X based on the pot cover correction update coefficient k and the background C to obtain a corrected image after removing the pot cover effect.

[0014] Based on the above infrared image pot cover effect correction method, the present invention also provides a computer storage medium.

[0015] A computer storage medium comprises a memory and a computer program stored in the memory. When the computer program is executed by a processor, the infrared image pot cover effect correction method as described above is implemented.

[0016] The beneficial effect of the present invention is that in the infrared image pot cover effect correction method, system and computer storage medium of the present invention, by pre-storing the background C, and then using the current pre-corrected image X and the background C to calculate a correction coefficient k, the correction coefficient k only needs to obtain the current pre-corrected image X of each frame in real time during the specific implementation process. and X i,j ,Finally, the corrected image is obtained by calculation, the pot cover removal effect is good and the calculation process is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of a method for correcting the pot cover effect of an infrared image according to the present invention;

[0018] Figure 2 The present invention is a structural block diagram of an infrared image pot cover effect correction system. DETAILED DESCRIPTION

[0019] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0020] like Figure 1 As shown, a method for correcting the pot cover effect of an infrared image includes the following steps S1-S3:

[0021] S1, collect the pot cover image C0, and calculate the mean value of the pot cover image C0 The pot cover image C0 and the mean Perform difference processing to obtain a difference image C; and use the difference image C as the background C.

[0022] The S1 is specifically:

[0023] S11, directing the infrared core to a black body and adjusting the temperature of the black body, when a relatively obvious pot cover effect appears in the image sensed by the infrared core, the pot cover image C0 at this time is collected by a two-point correction method, that is, 14-bit data C0 after the two-point correction is collected at this time; wherein, a relatively obvious pot cover effect generally appears when the oven is baked for more than 1 hour, and the four corners and the frame of the image and the center of the image are clearly black and white, that is, the four corners are bright and the center is black;

[0024] S12, performing mean filtering on the pot cover image C0 to reduce the non-uniformity in the background, and calculating the mean of the pot cover image C0

[0025] S13, comparing the pot cover image C0 with the mean Performing difference processing to obtain a difference image C; using the difference image C as a background C; and storing the background C in an infrared core;

[0026] Then, the expression of the background C is,

[0027] S2, using the background C to calculate the pot cover correction coefficient k0 of the current pre-corrected image X, and updating the pot cover correction coefficient k0 to obtain a pot cover correction update coefficient k.

[0028] The S2 is specifically:

[0029] S21, according to the background C and the current pre-corrected image X, find an initial coefficient k′ so that k′·C is closest to the three-dimensional curved surface image shape of the current pre-corrected image X;

[0030] Wherein, when k′·C is closest to the three-dimensional curved surface image shape of the current pre-corrected image X, the following equation is satisfied:

[0031]

[0032] Specifically, Min S(k′,b) is The minimum value of X i,jis the value at the coordinate (i, j) in the current pre-corrected image X, C i,j is the value at the coordinate (i, j) in the background C, and b is a constant; since the mean value of the background C is already zero, in order to ensure that the mean value of the image before and after correction remains unchanged, only the correction coefficient needs to be used. Then, when the mean value of the background C is zero, the expression of the initial coefficient k′ is,

[0033]

[0034] Since the value after the decimal point has an impact on the final result (the actual mean is not 0) when the mean of the background C is set to zero, the following S22-S23 needs to be executed after the mean of the background C is reset to zero.

[0035] S22, after the mean value of the background C is returned to zero, calculating the matrix and sumC of the background C;

[0036] S23, based on the initial coefficient k′, combined with the matrix and sumC of the background C and the number of points and the mean of the current pre-corrected image X, calculate the pot lid correction coefficient k0 of the current pre-corrected image X; wherein the expression of the pot lid correction coefficient k0 of the current pre-corrected image X is,

[0037]

[0038] Specifically, N is the number of points of the current pre-corrected image X, is the mean value of the current pre-corrected image X;

[0039] S24, updating the pot cover correction coefficient k0 of the current pre-corrected image X to obtain the pot cover correction update coefficient k of the current pre-corrected image X; wherein the expression of the pot cover correction update coefficient k of the current pre-corrected image X is,

[0040] k=α·k0+(1-α)·k -1 ;

[0041] Specifically, α is the weight, k -1 Update coefficients for pot lid correction of the previous pre-corrected image.

[0042] In this specific embodiment, the calculation formula of the matrix of the background C and sumC is,

[0043]

[0044] The mean value of the current pre-corrected image X The calculation formula is,

[0045]

[0046] S3, performing pot cover correction on the current pre-corrected image X based on the pot cover correction update coefficient k and the background C, to obtain a corrected image after removing the pot cover effect

[0047] In S3, the correction formula for performing pot cover correction on the current pre-corrected image X based on the pot cover correction update coefficient k and the background C is:

[0048]

[0049] in, It is the infrared image obtained after the current pre-corrected image X is corrected by the pot cover.

[0050] The method of the present invention is described below with reference to specific examples.

[0051] Since there are multiple divisions and floating-point calculations in the process of calculating the pot lid correction update coefficient k of the current pre-corrected image X, sumC and sumdiv are calculated using embedded calculations.

[0052] in,

[0053] 1. After the infrared camera is turned on, turn off all automatic correction functions, and put the infrared camera with the lens cap on for more than one hour until an obvious pot lid effect appears in the image;

[0054] 2. The logic part collects the current pot cover image and stores it in DDR as a template. The embedded part reads out a pot cover image in DDR and calculates the image mean.

[0055] 3. Calculate the difference template C (as background C) between the pot cover image and the image mean and write it into DDR, and calculate sumC and sum div according to the formula and transmit them to the logic part;

[0056] 4. Logically read the background C stored in DDR, sumC and sumdiv calculated by embedded system, and the current pre-corrected image X, according to the formula Calculate the pot lid correction coefficient k0 of the current pre-corrected image X, and then use the formula k = α·k0+(1-α)·k -1 Iteratively update the pot cover correction coefficient k0 of the current pre-corrected image X to determine the pot cover correction update coefficient k of the current pre-corrected image X;

[0057] 5. Update the pot lid correction coefficient k of the current pre-corrected image X according to the formula The image data with the background C subtracted is calculated to be the infrared image after pot cover correction.

[0058] Based on the above infrared image pot cover effect correction method, the present invention also provides an infrared image pot cover effect correction system.

[0059] like Figure 2 As shown, an infrared image pot cover effect correction system includes the following modules:

[0060] The background generation module is used to collect the pot cover image C0 and calculate the mean value of the pot cover image C0. The pot cover image C0 and the mean Performing difference processing to obtain a difference image C; using the difference image C as the background C;

[0061] A coefficient calculation module, which is used to calculate a pot cover correction coefficient k0 of the current pre-corrected image X using the background C, and update the pot cover correction coefficient k0 to obtain a pot cover correction update coefficient k;

[0062] A correction module is used to perform pot cover correction on the current pre-corrected image X based on the pot cover correction update coefficient k and the background C to obtain a corrected image after removing the pot cover effect.

[0063] Based on the above infrared image pot cover effect correction method, the present invention also provides a computer storage medium.

[0064] A computer storage medium comprises a memory and a computer program stored in the memory. When the computer program is executed by a processor, the infrared image pot cover effect correction method as described above is implemented.

[0065] In the method, system and computer storage medium for correcting the pot lid effect of infrared images of the present invention, a correction coefficient k is calculated by pre-storing the background C and then using the current pre-corrected image X and the background C. In the specific implementation process, the correction coefficient k only needs to obtain the current pre-corrected image X of each frame in real time. and X i,j Finally, the corrected image is obtained by calculation, the pot cover removal effect is good and the calculation process is simple. Through the present invention, the pot cover effect of the infrared image in the infrared thermal imager can be suppressed, the quality of the infrared image is improved, and the target recognition ability of the infrared image is improved.

[0066] 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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for correcting the pot cover effect of infrared images, characterized in that: The following steps are included: S1, collecting pot cover images , and calculate the pot cover image The mean , the pot cover image With the mean Perform difference processing to obtain the difference image ; The difference image As background ; S2, using the background Calculate the current pre-corrected image Lid correction factor , and the lid correction factor Update to get the pot cover correction update coefficient ; S3, based on the pot cover correction update coefficient And the background The current pre-corrected image Perform pot lid correction to obtain the corrected image after removing the pot lid effect ; The S2 is specifically: S21, according to the background and the current pre-corrected image , find an initial coefficient ,make With the current pre-corrected image The shape of the three-dimensional surface image is closest; Among them, when With the current pre-corrected image The three-dimensional surface image shape is closest to the following equation: ； Specifically, for The minimum value of For the current pre-calibration Positive image middle The value at the coordinate, For the background middle The value at the coordinate, is a constant; then in the background When the mean is zero, the initial coefficient The expression of is, ； S22, in the background After the mean of is returned to zero, the background The matrix and ; S23, based on the initial coefficient , combined with the background The matrix and and the current pre-corrected image The number of points and the mean value are used to calculate the current pre-corrected image Lid correction factor ; Wherein, the current pre-corrected image Lid correction factor The expression of is, ； Specifically, The current pre-corrected image The number of points, The current pre-corrected image The mean of S24, the current pre-corrected image Lid correction factor Update to obtain the current pre-corrected image The lid correction update factor ; Wherein, the current pre-corrected image The lid correction update factor The expression of is, ； Specifically, is the weight, Update coefficients for pot lid correction of the previous pre-corrected image.

2. The method for correcting the pot cover effect of infrared images according to claim 1, characterized in that: The S1 is specifically: S11, directing the infrared core toward the black body and adjusting the temperature of the black body, when a pot cover effect appears in the image sensed by the infrared core, collecting the pot cover image at this time by a two-point correction method ; S12, processing the pot cover image Perform mean filtering to calculate the pot cover image The mean ; S13, the pot cover image With the mean Perform difference processing to obtain the difference image ; The difference image As background ; Then, the background The expression of is, .

3. The method for correcting the pot cover effect of infrared images according to claim 1, characterized in that: The background The matrix and The calculation formula is, ； The current pre-corrected image The mean The calculation formula is, 。 4. The method for correcting the pot cover effect of infrared images according to claim 1, characterized in that: In S3, the update coefficient is corrected based on the pot cover And the background The current pre-corrected image The correction formula for pot cover correction is: ； in, For the current pre-corrected image Infrared image after pot lid correction.

5. An infrared image pot cover effect correction system, characterized in that: The method for correcting the pot cover effect of infrared images as claimed in any one of claims 1 to 4 comprises the following modules: Background generation module, which is used to collect pot cover images , and calculate the pot cover image The mean , the pot cover image With the mean Perform difference processing to obtain the difference image ; The difference image As background ; A coefficient calculation module is used to utilize the background Calculate the current pre-corrected image Lid correction factor , and the lid correction factor Update to get the pot cover correction update coefficient ; A correction module, which is used to correct the update coefficient based on the pot cover And the background The current pre-corrected image Perform pot lid correction to obtain the corrected image after removing the pot lid effect .

6. A computer storage medium, characterized in that: It comprises a memory and a computer program stored in the memory, and when the computer program is executed by a processor, the infrared image pot cover effect correction method as claimed in any one of claims 1 to 4 is implemented.

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