Method for improving image quality of infrared equipment in complex environment based on temperature compensation

Abstract

The invention discloses a method for improving the image quality of infrared equipment in a complex environment based on temperature compensation, and the method comprises the steps: firstly obtaining the focal plane temperature of an infrared movement detector and the mean value of the gray value of a separation blade at different environment temperatures, and fitting the relation between the focal plane temperature and the mean value of the imaging gray value of the separation blade at each environment temperature; then, the focal plane temperature, the block piece gray value and the block piece gray average value are recorded when the block piece is hit each time, and the predicted value of the block piece gray average value and the difference value are calculated; and finally, calculating the focal plane temperature value and the absolute value of the difference between the focal plane temperature value and the absolute value after the separation blade is punched each time, and comparing the absolute value with a threshold value to determine the gray value of the current separation blade so as to correct the output gray value of the detector. According to the invention, through real-time temperature compensation, the image quality and the temperature measurement precision of the infrared equipment can be improved.

Description

Technical Field

[0001] This invention belongs to the field of infrared imaging technology, specifically a method for improving the image quality of infrared devices in complex environments based on temperature compensation. Background Technology

[0002] The core advantages of infrared imaging technology:

[0003] 1) It has strong penetrating power, capable of penetrating obstacles such as dense smoke and fog, facilitating visibility.

[0004] It can operate in harsh environments and is widely used in perimeter protection, intrusion alarms, hunting, and outdoor applications.

[0005] 2) High clarity at night: Infrared imaging technology can provide high clarity at night or in low-light environments.

[0006] The image below is clear.

[0007] 3) Good concealment: Infrared thermal imaging is a passive imaging method, requiring no external light source, and has relatively high concealment.

[0008] Good privacy.

[0009] 4) Strong target recognition capability; infrared imaging technology can capture the target and its surrounding environment.

[0010] Temperature differences create images with high contrast and long range, which helps in the detection of thermal targets.

[0011] Based on the advantages of infrared thermal imaging, with the continuous development of low-altitude economy and drone technology, the application of drone + thermal imaging is becoming more and more widespread. Especially in applications such as drone power line inspection, drone tunnel inspection, drone urban security inspection, and drone non-cooperative target strike, drone thermal imaging can quickly detect suspicious monitoring targets, provide necessary measures in a timely manner, eliminate safety hazards, and reduce losses.

[0012] Taking the application of UAV thermal imaging in power transmission line inspection as an example, the presence of defects in the insulation terminals of power transmission lines can determine whether there are any safety hazards in the operation of the lines. UAV inspection of power transmission line insulation terminals typically relies on thermal imaging images of the insulation terminals, using AI target detection methods to detect the presence of defective insulation terminals in the images. While this method can effectively and quickly detect defective insulation terminals in power transmission lines, it also has a high rate of missed and false detections. Missed detections, in particular, can lead to incalculable losses in severe cases.

[0013] There is also an infrared temperature measurement-based solution, which assumes that if the temperature of the insulating terminal is high, the insulating terminal is defective. This solution makes good use of the infrared radiation characteristics. However, the working environment of transmission lines is mostly in the field, with diverse environmental changes, and the temperature measurement accuracy has a large error, resulting in missed and false alarms in the detection of insulating terminal defects.

[0014] Regardless of whether the solution is based on infrared imaging or infrared temperature measurement, the complex working environment and the changes in wind speed during the rapid flight of the drone will cause the temperature of the thermal imaging equipment to change rapidly. Due to the inherent material properties of infrared imaging, when the temperature changes rapidly, it will affect the output response of the detector, ultimately affecting the quality of infrared images and the accuracy of infrared temperature measurement. This will greatly affect the false alarms and missed alarms of target detection during the drone power line inspection process. Summary of the Invention

[0015] To address the problem of reduced infrared image quality and accuracy due to rapid temperature changes in infrared devices caused by external environmental variations, this invention proposes a temperature compensation-based method to improve image quality in complex environments. The advantages of this invention are:

[0016] A method for improving the image quality of infrared devices in complex environments based on temperature compensation, comprising the following steps:

[0017] Step 1: Obtain the focal plane temperature of the infrared detector and the average grayscale value of the infrared detector baffle under different ambient temperatures;

[0018] Step 2: Fit the focal plane temperature under various ambient temperatures The mean gray value of the image of the baffle The relationship between them;

[0019] * + * +

[0020] in, , , The coefficient is obtained by taking the average value of the focal plane temperature and the baffle gray value obtained in step 1.

[0021] Step 3: When the infrared sensor is working, record the temperature of the focal plane each time the baffle is activated. baffle grayscale value and the average grayscale value of the baffle ; Represents the row coordinates of the image. Represents the column coordinates of the image. And given... , , Temperature of the focal plane Under the premise of obtaining the mean gray value of the baffle image in step 2 With focal plane temperature The relationship is used to determine the focal plane temperature at the start of the baffle plate operation. grayscale value of lower baffle

[0022] Mean forecast Further calculation of the average gray value of the baffle Difference. Further calculation. and Difference .

[0023] Step 4: After each baffle is applied, monitor the focal plane temperature of the detector in real time. Calculate the temperature value The focal plane temperature value recorded when the baffle was first applied. The absolute value of the difference .

[0024] when Greater than the set threshold At this moment, it is assumed that the ambient temperature of the movement changes abruptly, and the movement is operating under complex conditions. The grayscale value of the baffle at the current moment is... = * + * + + .

[0025] when Less than the set threshold At that time, the current grayscale value of the baffle .

[0026] Step 5: Calculate the corrected detector output grayscale value:

[0027] +C.

[0028] in, C represents the calibrated empirical value.

[0029] The advantages of this invention are as follows: This invention is a method for improving the image quality of infrared devices in complex environments based on temperature compensation. By improving the image quality and temperature measurement accuracy of infrared devices through real-time temperature compensation, it effectively reduces the false alarms and missed alarms in the detection of defects in power transmission line insulation terminals. Compared with traditional infrared devices, it can quickly adapt to use in complex environments, especially in scenarios with complex weather or rapid changes in ambient temperature in the field, thereby improving the quality of infrared images based on real-time temperature compensation. Attached Figure Description

[0030] Figure 1 This is a flowchart of the method for improving the image quality of infrared devices in complex environments based on temperature compensation according to the present invention.

[0031] Figure 2 The grayscale image output by the infrared core detector using the method of this invention;

[0032] Figure 3 The image shown is a grayscale image output by an infrared detector that does not use the method of this invention. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings.

[0034] This invention relates to a method for improving the image quality of infrared devices in complex environments based on temperature compensation. The specific steps are as follows:

[0035] Step 1: Obtain the focal plane temperature of the infrared detector and the average grayscale value of the infrared detector baffle under different ambient temperatures.

[0036] 101. Place the infrared sensor in a high-low temperature chamber with an ambient temperature of -20℃. After 30 minutes, once the infrared sensor has stabilized, record the focal plane temperature of the infrared sensor detector at the current ambient temperature, and mark it as [symbol missing]. Simultaneously, the image grayscale value of the infrared sensor baffle at the current ambient temperature is collected as a marker. ( Represents the row coordinates of the image. (Represents the column coordinates of the image); further, through the preset storage address in the infrared core FLASH storage area. Read the grayscale data of the baffle image and calculate the mean of the grayscale values ​​of the baffle image. , For the number of rows in the image, This represents the number of columns in the image.

[0037] 102. Place the infrared sensor in a high-low temperature chamber with an ambient temperature of 0℃. After 30 minutes, once the infrared sensor has stabilized, record the focal plane temperature of the infrared sensor detector at the current ambient temperature, and mark it as [symbol missing]. The image grayscale value of the baffle under the current ambient temperature is marked as follows: ( Furthermore, the preset storage address in the infrared core FLASH storage area is used. Read the grayscale data of the baffle image and calculate the mean of the grayscale values ​​of the baffle image. , For the number of rows in the image, This represents the number of columns in the image.

[0038] 103. Place the infrared sensor in a high-low temperature chamber with an ambient temperature of 20°C. After 30 minutes, once the infrared sensor has stabilized, record the focal plane temperature of the infrared sensor detector at the current ambient temperature, and mark it as [symbol missing]. The grayscale value of the baffle under the current ambient temperature is collected as a marker. ( Furthermore, the preset storage address in the infrared core FLASH storage area is used. Read the grayscale data of the baffle image and calculate the mean of the grayscale values ​​of the baffle image. , For the number of rows in the image, This represents the number of columns in the image.

[0039] 104. Place the infrared sensor in a high-low temperature chamber with an ambient temperature of 40℃. After 30 minutes, once the infrared sensor has stabilized, record the focal plane temperature of the infrared sensor detector at the current ambient temperature, and mark it as [symbol missing]. The grayscale value of the baffle under the current ambient temperature is collected as a marker. ( Furthermore, the preset storage address in the infrared core FLASH storage area is used... Read the grayscale data of the baffle image and calculate the mean of the grayscale values ​​of the baffle image. , For the number of rows in the image, This represents the number of columns in the image.

[0040] 105. Place the infrared sensor in a high-low temperature chamber with an ambient temperature of 60℃. After 30 minutes, once the infrared sensor has stabilized, record the focal plane temperature of the infrared sensor detector at the current ambient temperature, and mark it as [symbol missing]. The grayscale value of the baffle under the current ambient temperature is collected as a marker. ( Furthermore, the preset storage address in the infrared core FLASH storage area is used... Read the grayscale data of the baffle image and calculate the mean of the grayscale values ​​of the baffle image. , For the number of rows in the image, This represents the number of columns in the image.

[0041] Step 2: Fit the mean gray value of the baffle image using a quadratic equation. With focal plane temperature Relationship:

[0042] * + * +

[0043] Based on the temperature values ​​calibrated in steps one through five , , , , and mean , , , , The quadratic equation in one variable is obtained by calculation: * + * + coefficient , , .

[0044] Step 3: When the infrared sensor is working, every... The shield is activated once every few minutes. Record the temperature of the focal plane each time the baffle is applied. grayscale value of the baffle and the average grayscale value of the baffle and in known , , Temperature of the focal plane Under the premise of obtaining the mean gray value of the baffle image in step 2 With focal plane temperature The relationship is used to determine the focal plane temperature at the start of the baffle plate operation. Predicted mean grayscale value of lower baffle ;

[0045] * + * +

[0046] Further calculations and Difference .

[0047]

[0048] At each start of the shot chuck, record the temperature of the focal plane at the current moment. grayscale value of the baffle and the average grayscale value of the baffle And the calculated predicted average grayscale value of the baffle Update the previous record.

[0049] Step 4: After each baffle is applied, monitor the focal plane temperature of the detector in real time. Computer chip detector focal plane temperature value The focal plane temperature value recorded when the baffle plate was first applied. The absolute value of the difference :

[0050]

[0051] when Greater than the set threshold At this time, it is assumed that the ambient temperature of the movement changes abruptly, and the movement is operating under complex conditions. The current grayscale value of the baffle is... = * + * + + .

[0052] when Less than the set threshold At that time, the current grayscale value of the baffle .

[0053] Step 5: Calculate the corrected detector output grayscale value:

[0054] +C.

[0055] in, C represents the calibrated empirical value; Before correction .

[0056] The above-mentioned method for improving the image quality of infrared devices in complex environments based on temperature compensation, compared with traditional infrared devices, recalculates the grayscale value of the baffle in real time by monitoring the temperature change of the focal plane after the infrared core has applied the baffle. According to the formula +C performs real-time correction of the grayscale values ​​output by the infrared sensor. This corrects for image quality degradation caused by sudden temperature changes in the sensor due to environmental variations. Figure 2 and Figure 3 As shown, the grayscale images output by the infrared core detector are obtained without and after using the method of the present invention. It can be seen that the uniformity and quality of the grayscale images output after using the method of the present invention are significantly improved.

[0057] This invention provides a method for improving the image quality of infrared devices in complex environments based on temperature compensation. It can be applied to various cooled and uncooled infrared core devices, enabling the infrared core to quickly adapt to complex weather conditions or rapidly changing ambient temperatures in the field, thereby greatly improving the quality of infrared images.

Claims

1. A method for improving the image quality of infrared devices in complex environments based on temperature compensation, characterized in that: The steps are as follows: Step 1: Obtain the focal plane temperature of the infrared detector and the average grayscale value of the infrared detector baffle under different ambient temperatures; Step 2: Fit the focal plane temperature under various ambient temperatures The mean gray value of the image of the baffle The relationship between them; * + * + in, , , The coefficient is obtained by taking the average value of the focal plane temperature and the baffle gray value obtained in step 1; Step 3: When the infrared sensor is working, record the temperature of the focal plane each time the baffle is activated. baffle grayscale value and the average grayscale value of the baffle ; Represents the row coordinates of the image. Represents the column coordinates of the image; and in the known , , Temperature of the focal plane Under the premise of obtaining the mean gray value of the baffle image in step 2 With focal plane temperature The relationship is used to determine the focal plane temperature at the start of the baffle plate operation. Predicted mean grayscale value of lower baffle Further calculation of the average gray value of the baffle Difference; further calculation and Difference ; Step 4: After each baffle is applied, monitor the focal plane temperature of the detector in real time. Calculate the temperature value The focal plane temperature value recorded when the baffle was first applied. The absolute value of the difference ; when Greater than the set threshold At this time, it is assumed that the ambient temperature of the movement changes abruptly, and the movement is operating under complex conditions. When the gray value of the baffle plate changes... = * + * + + ; when Less than the set threshold At that time, the current grayscale value of the baffle ; Step 5: Calculate the corrected detector output grayscale value: +C； in, C represents the calibrated empirical value.

2. The method for improving the image quality of infrared devices in complex environments based on temperature compensation as described in claim 1, characterized in that: In step 1, the selected temperature should cover -40°C to 70°C.

3. The method for improving the image quality of infrared devices in complex environments based on temperature compensation as described in claim 1, characterized in that: Step 1, the specific method is as follows: Place the infrared sensor in an ambient temperature of C k In the high and low temperature chamber, after 30 minutes, once the infrared sensor has stabilized, record the current ambient temperature (C). k The focal plane temperature of the infrared detector is denoted as... k represents the ambient temperature number, k = 1, 2, ..., D, where D is the number of selected temperatures; simultaneously, the current ambient temperature C is collected. k The image grayscale value of the lower infrared sensor baffle is marked as follows: Furthermore, by using a preset storage address in the infrared sensor's FLASH storage area, the grayscale data of the image of the baffle is read, and the average grayscale value of the image of the baffle is calculated. , For the number of rows in the image, This represents the number of columns in the image.

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