Infrared channel low-temperature difference object imaging method, device, circuit and storage medium

Abstract

Embodiments of the present application provide an infrared channel low-temperature-difference object imaging method, device, circuit and storage medium. The method comprises: converting an infrared signal into a voltage signal when an infrared detector detects the infrared signal of a to-be-measured object; calibrating the voltage signal through a signal conditioning circuit to compensate for measurement error; isolating the calibrated voltage signal through a first isolation circuit, and identifying the maximum voltage value in the isolated voltage signal through a peak value detection circuit; determining an analog-to-digital converter matched with a signal acquisition circuit according to the range in which the maximum voltage value is located, to switch the analog-to-digital converter of the signal acquisition circuit; converting the voltage signal into a corresponding digital signal through the signal acquisition circuit; determining a gray value mapping function according to the maximum voltage value and the digital signal, to convert the digital signal into image gray value data based on the gray value mapping function; and generating a gray image of the to-be-measured object according to the image gray value data.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photoelectric detection, in particular to an infrared channel low-temperature-difference object imaging method, device, circuit, storage medium and computer program product. BACKGROUND

[0002] Infrared imaging technology is a technology that uses the natural emission or reflection of infrared radiation from objects to perform non-contact imaging. This technology relies on infrared detectors to capture the infrared energy emitted by objects of different temperatures and convert it into visual images. In normal or high-temperature environments, infrared imaging technology has been widely used due to its unique advantages. For example, in the dark or insufficient light conditions, infrared imaging technology can be used for night vision monitoring to help security personnel identify potential security threats. In the industrial field, thermal imaging diagnosis technology uses infrared imaging to detect hot spots in equipment, predict potential failures and maintenance needs. In addition, infrared imaging also plays an important role in medical, scientific research, military and other fields.

[0003] However, when it comes to low-temperature environments, infrared imaging technology faces a series of challenges. In low-temperature environments, the temperature difference between objects is often very small, which poses a problem for traditional infrared imaging technology. Due to the small temperature gradient, the contrast of the infrared image is reduced, resulting in a decrease in the recognition of object details and boundaries. In this case, even small temperature changes can carry important information, but traditional infrared imaging systems cannot effectively capture and display this information. This low-contrast image limits the application of infrared imaging in cold chain logistics, food storage, power line icing monitoring and other fields, which often require accurate monitoring of low-temperature-difference objects. For example, icing is a common phenomenon on power lines in cold climates, which can cause the weight of the conductor to increase, the elasticity to decrease, and even cause line breakage and other serious accidents. Therefore, real-time monitoring of icing conditions is of great significance to ensure the stable operation of the power system. However, in the field of power line icing monitoring, due to the small temperature difference between the ice and the conductor, the infrared imaging system has difficulty in clearly depicting the outline and thickness of the ice, which affects the accurate judgment of the icing condition by the staff. Secondly, in low-temperature environments, the thermal properties of ice and conductors are similar, making it difficult for infrared imaging systems to distinguish between ice layers and conductors, thus failing to provide quantitative analysis of ice thickness. In addition, due to the influence of atmospheric humidity, wind speed and other factors in low-temperature environments, the infrared image may have noise, further reducing the reliability of the monitoring data. Therefore, it is urgent to enhance the quality of infrared imaging and improve the contrast and resolution of infrared images to contribute to the safe production of the power system and other industries. SUMMARY

[0004] The embodiment of the present application aims to provide an infrared channel low-temperature-difference object imaging method, device, circuit, storage medium and computer program product, so as to solve the problem of difficulty in imaging of small temperature gradient between objects in a low-temperature environment in the prior art.

[0005] In order to achieve the above-mentioned purpose, the first aspect of the present application provides an infrared channel low-temperature-difference object imaging method applied to a low-temperature-difference object imaging circuit, the low-temperature-difference object imaging circuit comprising an infrared detector, a signal conditioning circuit, a signal monitoring circuit and a signal acquisition circuit, the infrared detector being connected in series with the signal conditioning circuit, the signal monitoring circuit being connected in parallel with the signal acquisition circuit and then connected in series with the signal conditioning circuit, the signal monitoring circuit comprising a first isolation circuit and a peak detection circuit, the first isolation circuit comprising a voltage follower, the peak detection circuit comprising an operational amplifier, a diode and a capacitor, the signal acquisition circuit comprising a second isolation circuit and a digital-to-analog conversion module, the digital-to-analog conversion module comprising a plurality of analog-to-digital converters connected in parallel and having different ranges, each analog-to-digital converter being connected in series with an electronic switch, the method comprising:

[0006] In the case that the infrared detector detects an infrared signal of a to-be-measured object, converting the infrared signal into a voltage signal;

[0007] Inputting the voltage signal into the signal conditioning circuit to calibrate the voltage signal through the signal conditioning circuit to compensate for measurement errors;

[0008] Inputting the calibrated voltage signal into the signal monitoring circuit to isolate the voltage signal through the first isolation circuit and identify the maximum voltage value in the isolated voltage signal through the peak detection circuit;

[0009] Determining an analog-to-digital converter matched with the signal acquisition circuit according to the range where the maximum voltage value is located, to switch the analog-to-digital converters of the signal acquisition circuit by controlling the electronic switches connected in series with the matched analog-to-digital converter to close;

[0010] Inputting the voltage signal into the signal acquisition circuit to convert the voltage signal into a corresponding digital signal through the signal acquisition circuit;

[0011] Determining a gray value mapping function according to the maximum voltage value and the digital signal, to convert the digital signal into image gray value data based on the gray value mapping function;

[0012] Generating a gray image of the to-be-measured object according to the image gray value data.

[0013] In the embodiments of the present application, the infrared detector is internally provided with a first reference power supply, the first reference power supply comprises a voltage reference chip, and the method further comprises: in the case that the infrared detector is in a dark environment or does not detect an infrared signal of a to-be-measured object, delivering a voltage to the infrared detector by the first reference power supply; recording an output voltage of the infrared detector as a basic offset; calculating an offset error according to the output voltage and a preset reference voltage, so as to calibrate the voltage signal of the infrared detector and compensate for measurement error.

[0014] In the embodiments of the present application, the signal conditioning circuit comprises a second reference power supply and a compensation circuit, the second reference power supply comprises a voltage reference chip, the compensation circuit comprises a digital potentiometer internally provided with a plurality of series resistors and electronic switches, and the voltage signal is input to the signal conditioning circuit to calibrate the voltage signal by the signal conditioning circuit to compensate for measurement error, which comprises: inputting the voltage signal to the signal conditioning circuit, periodically controlling any electronic switch in the compensation circuit to be closed, so as to connect each node of the plurality of series resistors to the Uw end; acquiring the voltage between the Uw end and the Ul end, so as to calibrate the voltage signal by the voltage to compensate for measurement error.

[0015] In the embodiments of the present application, the gray value mapping function is determined according to the maximum voltage value and the voltage signal, and the voltage signal is converted into image gray value data based on the gray value mapping function, which comprises: in the case that the voltage signal is in an interval formed by a first voltage value and a second voltage value, the voltage signal is converted into image gray value data by a preset logarithmic exchange function, wherein the first voltage value is less than the second voltage value, and the second voltage value is a first decimal multiple of the maximum voltage value; in the case that the voltage signal is in an interval formed by the second voltage value and a third voltage value, the voltage signal is converted into image gray value data by a preset linear transformation function, wherein the second voltage value is less than the third voltage value, and the third voltage value is a second decimal multiple of the maximum voltage value; in the case that the voltage signal is in an interval formed by the third voltage value and the maximum voltage value, the voltage signal is converted into image gray value data by a preset inverse logarithmic transformation function.

[0016] In the embodiments of the present application, the method further comprises: constructing a neighborhood according to the gray image; setting an upper threshold value and a lower threshold value of the neighborhood; traversing all pixel points in the gray image to determine whether the gray value of each pixel point in all pixel points is greater than the upper threshold value or less than the lower threshold value; and determining the pixel points with the gray value greater than the upper threshold value or less than the lower threshold value as noise points, so as to remove the noise points.

[0017] In the embodiments of the present application, the upper threshold value and the lower threshold value of the neighborhood are determined according to formula (1):

[0018] (1),

[0019] wherein, is an upper threshold value, is a lower threshold value, is a mean value of the gray scale values of the pixels in the neighborhood, is a standard deviation of the gray scale values of the pixels in the neighborhood, is a constant.

[0020] The second aspect of the present application provides an infrared channel low-temperature difference object imaging device, comprising:

[0021] a memory configured to store instructions;

[0022] a processor configured to call the instructions from the memory and enable the above-mentioned infrared channel low-temperature difference object imaging method when the instructions are executed.

[0023] The third aspect of the present application provides an infrared channel low-temperature difference object imaging circuit, comprising:

[0024] an infrared detector connected in series with a signal conditioning circuit, for converting an infrared signal into a voltage signal in the case of detecting the infrared signal of an object to be measured;

[0025] a signal conditioning circuit for calibrating the voltage signal to compensate for measurement errors;

[0026] a signal monitoring circuit connected in parallel with a signal acquisition circuit and connected in series with the signal conditioning circuit, comprising a first isolation circuit and a peak detection circuit, the first isolation circuit comprising a voltage follower, and the peak detection circuit comprising an operational amplifier, a diode and a capacitor, the signal monitoring circuit being configured to isolate the voltage signal through the first isolation circuit, and identify the maximum voltage value in the isolated voltage signal through the peak detection circuit;

[0027] a signal acquisition circuit comprising a second isolation circuit and a digital-to-analog conversion module, the digital-to-analog conversion module comprising a plurality of analog-to-digital converters connected in parallel and having different ranges, each analog-to-digital converter being connected in series with an electronic switch, for converting the voltage signal into a corresponding digital signal;

[0028] the above-mentioned infrared channel low-temperature difference object imaging device.

[0029] The fourth aspect of the present application provides a machine-readable storage medium having instructions stored thereon, the instructions causing the processor to be configured to perform the above-mentioned infrared channel low-temperature difference object imaging method when executed by the processor.

[0030] The fifth aspect of the present application provides a computer program product comprising a computer program, the computer program being configured to implement the above-mentioned infrared channel low-temperature difference object imaging method when executed by the processor.

[0031] The technical scheme, the infrared signal detected by the infrared detector is converted into a voltage signal, then the maximum voltage value of the voltage signal is identified by the signal monitoring circuit, and an analog-to-digital converter with a suitable range is adaptively selected, so that the resolution of voltage acquisition is improved, the digital signal collected is corresponded to the pre-defined gray value mapping table, and corresponding gray value data is generated. The method improves the resolution of the infrared imaging technology for low-temperature difference objects, and can provide clear and reliable infrared images for various engineering fields.

[0032] Other features and advantages of the embodiments of the present application will be described in detail in the following specific implementation part. BRIEF DESCRIPTION OF DRAWINGS

[0033] The accompanying drawings are included to provide a further understanding of the embodiments of the present application, and constitute a part of the specification, and are used together with the following specific implementation to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the drawings:

[0034] Figure 1 An application environment schematic diagram of an infrared channel low-temperature difference object imaging method according to an embodiment of the present application is schematically shown;

[0035] Figure 2 A flowchart of an infrared channel low-temperature difference object imaging method according to an embodiment of the present application is schematically shown;

[0036] Figure 3 A schematic diagram of a compensation circuit according to an embodiment of the present application is schematically shown;

[0037] Figure 4 A gray value mapping function diagram according to an embodiment of the present application is schematically shown;

[0038] Figure 5 An infrared gray image 3*3 neighborhood diagram according to an embodiment of the present application is schematically shown;

[0039] Figure 6 An internal structure diagram of a computer device according to an embodiment of the present application is schematically shown. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiments of the present application, and is not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0041] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the technical features indicated or implying the number of technical features indicated. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor within the protection scope claimed by the present application.

[0042] The infrared channel low temperature difference object imaging method provided by the present application can be applied to the application environment as shown in Figure 1 As shown in Figure 1 A schematic diagram of an infrared channel low temperature difference object imaging circuit is provided, which includes an infrared detector, a signal conditioning circuit, a signal monitoring circuit and a signal acquisition circuit. The infrared detector is connected in series with the signal conditioning circuit, and the signal monitoring circuit and the signal acquisition circuit are connected in parallel and then connected in series with the signal conditioning circuit. The infrared detector can be used to convert the infrared signal into a voltage signal when detecting the infrared signal of the object to be measured. The signal conditioning circuit can be used to calibrate the voltage signal to compensate for measurement error. The signal monitoring circuit includes a first isolation circuit and a peak detection circuit, the first isolation circuit includes a voltage follower, the peak detection circuit includes an operational amplifier, a diode and a capacitor, and the signal monitoring circuit can be used to isolate the voltage signal through the first isolation circuit, and identify the maximum voltage value in the isolated voltage signal through the peak detection circuit. The signal acquisition circuit includes a second isolation circuit and a digital-to-analog conversion module, the digital-to-analog conversion module includes a plurality of analog-to-digital converters connected in parallel and having different ranges, and each analog-to-digital converter is connected in series with an electronic switch, which can be used to convert the voltage signal into a corresponding digital signal.

[0043] It should be noted that the processor can be a microprocessor, which can be connected in series with the signal monitoring circuit and the signal acquisition circuit connected in parallel with each other, and the processor can be selected as an FPGA chip with model XC7A100T. The FPGA chip can refer to a programmable logic chip, which can realize digital signal processing, image processing, communication protocol, control system and various digital circuit functions at the hardware level.

[0044] Figure 2 A flowchart of an infrared channel low temperature difference object imaging method according to an embodiment of the present application is schematically shown. As shown in Figure 2 The present application provides an infrared channel low temperature difference object imaging method, which can be applied to an infrared channel low temperature difference object imaging circuit, and can include the following steps:

[0045] In step 201, the infrared signal is converted into a voltage signal when the infrared detector detects the infrared signal of the object to be measured.

[0046] In the embodiments of the present application, it should be noted that the infrared detector can refer to a device that can convert the incident infrared radiation signal into an electrical signal output. Infrared radiation is electromagnetic wave with a wavelength between visible light and microwave, which cannot be perceived by the human eye. In order to perceive and measure the existence and intensity of such radiation, it is usually necessary to convert it into a measurable physical quantity. Modern infrared detectors mainly use infrared thermal effect and photoelectric effect, and the output of these effects is usually an electrical quantity, or can be converted into an electrical quantity by appropriate methods. In the technical solution, the infrared detector can convert the infrared signal into a voltage signal for output when detecting the infrared signal of the object to be measured.

[0047] In the embodiments of the present application, the infrared detector is built-in with a first reference power supply, the first reference power supply includes a voltage reference chip, and the method further includes: delivering a voltage to the infrared detector by the first reference power supply when the infrared detector is in a dark environment or does not detect the infrared signal of the object to be measured; recording the output voltage of the infrared detector as a basic offset; calculating an offset error according to the output voltage and a preset reference voltage to calibrate the voltage signal of the infrared detector to compensate for the measurement error.

[0048] In the embodiments, it should be noted that the infrared detector may have a measurement error, and the output voltage signal of the infrared detector may not be accurate. Therefore, in order to compensate for the measurement error caused by the infrared detector, a reference power supply can be built-in or external to the infrared detector to calibrate the voltage signal output by the infrared detector. The reference power supply can refer to providing a relatively stable voltage or current in the circuit as a comparison reference for the stable operation of other elements. The voltage reference chip is an integrated circuit that provides a stable and accurate reference voltage, mainly used for calibrating the voltage in other circuits to ensure that the voltage in the entire system remains stable and accurate. Therefore, the voltage reference chip can be selected as the built-in reference power supply of the infrared detector in the technical solution. Specifically, the voltage can be delivered to the infrared detector by the voltage reference chip when the infrared detector is in a dark environment or does not detect the infrared signal of the object to be measured. The output voltage of the infrared detector is recorded as a basic offset. Thus, the processor can calculate an offset error according to the output voltage and a preset reference voltage to calibrate the voltage signal of the infrared detector to compensate for the measurement error.

[0049] In step 202, the voltage signal is input to the signal conditioning circuit to calibrate the voltage signal through the signal conditioning circuit to compensate for the measurement error.

[0050] In the embodiment of the present application, it should be noted that the infrared detector may have measurement errors, and the output voltage signal of the infrared detector may not be accurate. Therefore, in order to compensate for the measurement error caused by the infrared detector, a reference power supply can be built-in or external to the infrared detector to calibrate the voltage signal output by the infrared detector. In the technical solution, the external reference power supply can be deployed in the signal conditioning circuit, so that the processor can input the voltage signal output by the infrared detector into the signal conditioning circuit to calibrate the voltage signal through the signal conditioning circuit to compensate for the measurement error.

[0051] In the embodiment of the present application, the signal conditioning circuit includes a second reference power supply and a compensation circuit, the second reference power supply includes a voltage reference chip, and the compensation circuit includes a digital potentiometer with a plurality of series resistors and electronic switches built-in. The voltage signal is input to the signal conditioning circuit to calibrate the voltage signal through the signal conditioning circuit to compensate for the measurement error, including: inputting the voltage signal to the signal conditioning circuit, periodically controlling any electronic switch in the compensation circuit to close, so as to connect each node of the plurality of series resistors to the Uw end; obtaining the voltage between the Uw end and the Ul end to calibrate the voltage signal through the voltage to compensate for the measurement error.

[0052] In the embodiment, it should be noted that the signal conditioning circuit includes a second reference power supply and a compensation circuit. The second reference power supply can be a voltage reference chip, and the compensation circuit includes a digital potentiometer with a plurality of series resistors and electronic switches built-in. The digital potentiometer can be an electronic component that controls the resistance value through a digital signal, also known as a digitally controlled programmable resistor or a resistive digital-to-analog converter (DAC).

[0053] As Figure 3As shown, a schematic diagram of a compensation circuit is provided. The compensation circuit can be selected as a digital potentiometer, with n resistors of the same resistance connected in series, and the two ends of each resistor connected through an electronic switch. The electronic switches L1 to Ln can be selected as MOSFET tubes. The MOSFET tube can refer to a semiconductor device, also known as a metal oxide semiconductor field effect transistor or insulated gate field effect tube. The MOSFET tube is mainly composed of metal (M), oxide (O) and semiconductor (S), and controls the conduction and cutoff of current through the electric field effect. Its working principle is to control the width of the conductive channel between the source and the drain by changing the gate voltage, thereby realizing the control of current. After the processor inputs the voltage signal to the signal conditioning circuit, only one electronic switch is closed at a time under the control of the digital signal, thereby connecting each node of the series resistor to the Uw end. The voltage between Uw and Ul is obtained, and the voltage between Uw and Ul is taken as the compensation voltage of the voltage signal output by the infrared detector, thereby compensating for the measurement error of the infrared detector. In step 203, the calibrated voltage signal is input to the signal monitoring circuit to isolate the voltage signal through the first isolation circuit, and the maximum voltage value in the isolated voltage signal is identified through the peak value detection circuit.

[0054] In the embodiments of the present application, it should be noted that the isolation circuit can refer to a circuit that completely isolates the input and output circuits by physical means. It transmits signals to the output end by using isolation elements, while blocking the conduction of current or interfering substances. The isolation circuit can realize signal transmission and power isolation, thereby providing higher safety and reliability. In the technical solution, as shown in Figure 2 The signal monitoring circuit includes a first isolation circuit and a peak value detection circuit. The first isolation circuit can include a voltage follower, which serves to isolate the signal so that the signal monitoring circuit does not affect the voltage signal output by the infrared detector. The peak value detection circuit can refer to an electronic circuit for measuring the maximum value (positive peak value) or minimum value (negative peak value) in the signal waveform, which is usually composed of a diode and a capacitor. In the technical solution, as shown in Figure 2 The peak value detection circuit includes an operational amplifier, a diode and a capacitor. The operational amplifier can be selected as an operational amplifier of type OPA350EA. The processor can input the calibrated voltage signal to the signal monitoring circuit to isolate the voltage signal through the first isolation circuit, and then identify the maximum voltage value in the isolated voltage signal through the peak value detection circuit.

[0055] In step 204, the analog-to-digital converter matched with the signal acquisition circuit is determined according to the range where the maximum voltage value is located, so as to switch the analog-to-digital converter of the signal acquisition circuit by controlling the closing of the electronic switches connected in series with the matched analog-to-digital converter.

[0056] In this embodiment, it should be noted that a digital-to-analog converter (DAC), also known as a digital-to-analog converter, is a device that converts digital signals into analog signals. A DAC typically consists of four parts: a weighted resistor network, an operational amplifier, a reference power supply, and an analog switch. Analog-to-digital converters (ADCs) generally use digital-to-analog converters (A / D converters), which convert continuous analog signals into discrete digital signals. In this technical solution, the signal acquisition circuit may include a second isolation circuit and a DAC module. The DAC module includes multiple parallel-connected ADCs with different ranges, each connected in series with an electronic switch. The second isolation circuit may include a voltage follower, which isolates the signal, ensuring that the signal monitoring circuit does not affect the voltage signal output by the infrared detector.

[0057] like Figure 2 As shown, in this technical solution, the digital-to-analog conversion module can be composed of three 8-bit analog-to-digital converters (ADCs): ADC1, ADC2, and ADC3. ADCs ADC1, ADC2, and ADC3 are connected in series with electronic switches K1, K2, and K3, respectively. Electronic switches K1, K2, and K3 can be selected as MOSFETs. The ranges of ADC1, ADC2, and ADC3 are 0 to 2.5V, 0 to 3.3V, and 0 to 5V, respectively. Therefore, the resolutions of ADC1, ADC2, and ADC3 can be:

[0058]

[0059]

[0060]

[0061] If the voltage signal to be acquired is in the range of 0 to 2.5V, then ADC1 can be selected to acquire voltage data. The resolution is 1.3 times higher than that of ADC2 and 2 times higher than that of ADC3.

[0062] Therefore, after the processor obtains the maximum voltage value of the voltage signal output by the infrared detector, it can determine the analog-to-digital converter (ADC) that matches the signal acquisition circuit based on the range of the maximum voltage value, and then switch the ADC of the signal acquisition circuit by controlling the closing of the electronic switch connected in series with the matched ADC.

[0063] Step 205: Input the voltage signal to the signal acquisition circuit so that the voltage signal can be converted into a corresponding digital signal.

[0064] In this embodiment, it should be noted that the voltage signal output by the infrared detector is a continuously changing analog signal, which can take on an infinite number of values ​​within a certain range. However, this technical solution requires discrete values ​​for subsequent calculations; therefore, the voltage signal needs to be converted into a corresponding digital signal. Specifically, after the processor switches the analog-to-digital converter (ADC) response based on the range of the obtained maximum voltage value, it can further input the voltage signal to the signal acquisition circuit to convert it into a corresponding digital signal.

[0065] Step 206: Determine the grayscale value mapping function based on the maximum voltage value and the digital signal, so as to convert the digital signal into image grayscale value data based on the grayscale value mapping function.

[0066] In this embodiment, it should be noted that grayscale data refers to the brightness or grayscale level of each pixel in a black and white image. In digital image processing, grayscale values ​​typically represent the brightness intensity of a pixel, ranging from 0 to 255, where 0 represents the darkest black and 255 represents the brightest white. A higher grayscale value indicates a brighter pixel; a lower grayscale value indicates a darker pixel. After obtaining the maximum voltage value output by the signal monitoring circuit and the digital signal output by the signal acquisition circuit, the processor can further determine a grayscale value mapping function based on the maximum voltage value and the digital signal, thereby further converting the digital signal into image grayscale data based on the grayscale value mapping function.

[0067] In this embodiment, determining a grayscale value mapping function based on the maximum voltage value and the voltage signal, and converting the voltage signal into image grayscale value data based on the grayscale value mapping function, includes: when the voltage signal is in the interval formed by the first voltage value and the second voltage value, converting the voltage signal into image grayscale value data through a preset logarithmic transformation function, wherein the first voltage value is less than the second voltage value, and the second voltage value is a first decimal multiple of the maximum voltage value; when the voltage signal is in the interval formed by the second voltage value and the third voltage value, converting the voltage signal into image grayscale value data through a preset linear transformation function, wherein the second voltage value is less than the third voltage value, and the third voltage value is a second decimal multiple of the maximum voltage value; when the voltage signal is in the interval formed by the third voltage value and the maximum voltage value, converting the voltage signal into image grayscale value data through a preset antilogarithmic transformation function.

[0068] In the embodiment, it is to be noted that the first voltage value is less than the second voltage value, the second voltage value is a first decimal multiple of the maximum voltage value, the second voltage value is less than the third voltage value, the third voltage value is a second decimal multiple of the maximum voltage value, the first voltage value can be 0V, the first decimal multiple can be 0.3, and the second decimal multiple can be 0.7. Thus, taking the maximum voltage value M as an example, the second voltage value can be 0.3M, and the third voltage value can be 0.7M.

[0069] Specifically, when the voltage signal is in [0, 0.3M), i.e., when the voltage signal is greater than or equal to 0 and less than 0.3M, a preset logarithmic exchange function can be selected to convert the voltage signal into image gray value data. For example, if the depth of the gray image is 8 bits and the maximum value of the voltage signal is 2.5V, when the voltage signal is 0 to 0.75V, the preset logarithmic exchange function is:

[0070] ,

[0071] The logarithmic transformation function can enhance the dark details of the gray image, wherein the logarithmic base number is a real number greater than 1, and the logarithmic base number is selected according to the dark detail requirement of the gray image. Here, the base number is selected to be 2.

[0072] When the voltage signal is in [0.3M, 0.7M], i.e., when the voltage signal is greater than or equal to 0.3M and less than or equal to 0.7M, a preset linear transformation function can be selected to convert the voltage signal into image gray value data. Specifically, for example, if the depth of the gray image is 8 bits and the maximum value of the voltage signal is 2.5V, when the voltage signal is 0.75 to 1.75V, the preset linear transformation function is:

[0073] ,

[0074] The linear transformation function can smooth the gray image and improve the visual effect of the image.

[0075] When the voltage signal is in (0.7M, M], i.e., when the voltage signal is greater than 0.7M and less than or equal to M, a preset inverse logarithmic transformation function can be selected to convert the voltage signal into image gray value data. Specifically, for example, if the depth of the gray image is 8 bits and the maximum value of the voltage signal is 2.5V, when the voltage signal is 1.75 to 2.5V, the preset inverse logarithmic transformation function is:

[0076] ,

[0077] The inverse logarithmic transformation function can enhance the bright details of the gray image, and the inverse logarithmic transformation function base number should be the same as the logarithmic transformation function base number.

[0078] In step 207, a gray image of the object to be measured is generated according to the image gray value data.

[0079] In the embodiment of the present application, it should be noted that after the processor determines the gray value mapping function according to the maximum voltage value and the digital signal, and converts the digital signal into image gray value data based on the gray value mapping function, the processor can further generate a gray image of the object to be measured according to the image gray value data.

[0080] In the embodiment of the present application, the method further comprises: constructing a neighborhood according to the gray image; setting an upper threshold and a lower threshold of the neighborhood; traversing all pixel points in the gray image to determine whether the gray value of each pixel point in all pixel points is greater than the upper threshold or less than the lower threshold; and determining the pixel points with the gray value greater than the upper threshold or less than the lower threshold as noise points for removing the noise points.

[0081] In the embodiment, it should be noted that in image processing, the neighborhood usually refers to a set of pixels around the center pixel. In the present technical solution, there may be many noise points in the obtained gray image, thereby affecting the clarity and quality of the image. Therefore, after obtaining the gray image of the infrared image, the image noise points can be identified and eliminated by the built-in noise reduction algorithm of the processor to improve the clarity and quality of the infrared gray image. Specifically, the processor can first construct a neighborhood according to the gray image, and set an upper threshold and a lower threshold of the neighborhood, and then traverse all pixel points in the gray image to determine whether the gray value of each pixel point in all pixel points is greater than the upper threshold or less than the lower threshold. If the pixel point is greater than the upper threshold or less than the lower threshold, it can be considered as a noise point, and the noise point needs to be removed. If the pixel point is greater than or equal to the lower threshold and less than or equal to the upper threshold, it can be considered as not a noise point, and the pixel point needs to be retained.

[0082] In the embodiment of the present application, the upper threshold and the lower threshold of the neighborhood are determined according to formula (1):

[0083] (1),

[0084] wherein, the upper threshold is the lower threshold is the average value of the gray values of the pixel points in the neighborhood is the standard deviation of the gray values of the pixel points in the neighborhood is and the constant is

[0085] In the embodiment, as shown in Figure 5 , a schematic diagram of a 3*3 neighborhood of an infrared gray image is provided. As shown in Figure 5For a certain point and its 3*3 neighborhood in the infrared gray image, the mean, standard deviation and median of the gray values in the neighborhood are solved, and the noise is eliminated according to the set threshold. If the gray values of each point in the neighborhood are: a 0=96, a 1=68, a 2=78, a 3=88, a 4=69, a 5=92, a 6=67, a 7=81, a 8=79, μ the mean σ and the standard deviation are respectively:

[0086]

[0087]

[0088] α =2, the upper threshold and the lower threshold are:

[0089]

[0090]

[0091] The gray value of the current pixel point λ 1≥ a 0≥ λ 2, so the current pixel point is not noise and is retained.

[0092] If the gray values of each point in the neighborhood are: a 0=128, a 1=68, a 2=78, a 3=88, a 4=69, a 5=92, a 6=67, a 7=81, a 8=79, μ the mean σ and the standard deviation are respectively:

[0093]

[0094]

[0095] α =2, the upper threshold and the lower threshold are:

[0096] ,​​​​​​

[0097] ,

[0098] Current pixel point gray value a 0 λ 1, so the current pixel point is determined as a noise point, and the current pixel point gray value a 0 is modified as the neighborhood median, that is a 0 = 79.

[0099] All pixel points in the image are traversed, and the above noise reduction algorithm is executed on all pixel points for which a neighborhood can be found, and an infrared gray image is output after removing the noise points.

[0100] The technical scheme, by converting the detected infrared signal into a voltage signal through an infrared detector, then identifying the maximum voltage value of the voltage signal through a signal monitoring circuit, and adaptively selecting an appropriate range of analog-to-digital converter, thereby improving the resolution of voltage acquisition, corresponding the collected digital signal with a predefined gray value mapping table, and generating corresponding gray value data. This method improves the resolution of infrared imaging technology for low temperature difference objects, and can provide clear and reliable infrared images for various engineering fields.

[0101] The embodiment of the present application provides a kind of infrared channel low temperature difference object imaging device, comprising:

[0102] Memory is configured to store instructions;

[0103] Processor is configured to call the instructions from the memory and can realize the above-mentioned infrared channel low temperature difference object imaging method when executing the instructions.

[0104] The embodiment of the present application provides a kind of machine readable storage medium, which stores instructions, and the instructions make the processor be configured to execute the above-mentioned infrared channel low temperature difference object imaging method when being executed by processor.

[0105] In one embodiment, a computer device can be provided, which can be a server, and its internal structure diagram can be as shown in Figure 6As shown in the figure. The computer device includes a processor A01, a network interface A02, a memory (not shown in the figure) and a database (not shown in the figure) connected through a system bus. Among them, the processor A01 of the computer device is used to provide computing and control capabilities. The memory of the computer device includes an internal memory A03 and a non-volatile storage medium A04. The non-volatile storage medium A04 stores an operating system B01, a computer program B02 and a database (not shown in the figure). The internal memory A03 provides an environment for the operating system B01 and the computer program B02 in the non-volatile storage medium A04 to run. The database of the computer device is used to store the infrared channel low-temperature difference object imaging method data. The network interface A02 of the computer device is used to communicate with the external terminal through the network connection. The computer program B02 is executed by the processor A01 to realize an infrared channel low-temperature difference object imaging method.

[0106] Those skilled in the art can understand that, Figure 6 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement.

[0107] The embodiment of the present application provides a device, which comprises a processor, a memory and a program stored in the memory and executable on the processor. When the processor executes the program, the following steps are implemented:

[0108] In the case that the infrared detector detects the infrared signal of the object to be measured, the infrared signal is converted into a voltage signal; the voltage signal is input to the signal conditioning circuit to calibrate the voltage signal through the signal conditioning circuit to compensate for measurement errors; the calibrated voltage signal is input to the signal monitoring circuit to process the voltage signal through the first isolation circuit, and the peak value detection circuit identifies the maximum voltage value in the voltage signal after isolation processing; the analog-to-digital converter matched with the signal acquisition circuit is determined according to the range where the maximum voltage value is located, so as to switch the analog-to-digital converter of the signal acquisition circuit by controlling the electronic switch connected in series with the matched analog-to-digital converter; the voltage signal is input to the signal acquisition circuit to convert the voltage signal into a corresponding digital signal through the signal acquisition circuit; the gray value mapping function is determined according to the maximum voltage value and the digital signal, so as to convert the digital signal into image gray value data based on the gray value mapping function; and the gray scale image of the object to be measured is generated according to the image gray value data.

[0109] The present application also provides a computer program product which, when executed on a data processing device, is adapted to execute the program of the initialization infrared channel low-temperature difference object imaging method step.

[0110] Those skilled in the art will appreciate that embodiments of the present application can be readily used as a method, a system or a computer program product. Accordingly, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application can take the form of a computer program product on one or more computer readable storage media (including, but not limited to, disk memory, CD-ROMs, optical storage devices, etc.) embodying computer readable program code.

[0111] The present application is described in reference to the flowchart illustrations and / or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0112] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0113] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0114] In one typical configuration, the computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0115] The memory can include non-persistent memory, random access memory (RAM), and / or non-volatile memory, such as read only memory (ROM) or flash memory (flash RAM), among others. The memory is an example of computer readable media.

[0116] Computer-readable media includes permanent and non-permanent, movable and non-movable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic tape disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible to a computing device. According to the definition herein, computer-readable media does not include transitory media such as modulated data signals and carriers.

[0117] It should also be noted that the terms "comprising", "containing", or any other variant thereof are intended to cover non-exclusive inclusions, so that a process, method, article or apparatus that includes a list of elements does not only include those elements, but also includes other elements not explicitly listed, or further includes elements inherent in such a process, method, article or apparatus. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or apparatus that includes the element.

[0118] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of claims of the present application.

Claims

1. A method for imaging objects with low temperature difference in infrared channels, characterized in that, An infrared channel cryogenic difference object imaging circuit is applied, comprising an infrared detector, a signal conditioning circuit, a signal monitoring circuit, and a signal acquisition circuit. The infrared detector is connected in series with the signal conditioning circuit. The signal monitoring circuit is connected in parallel with the signal acquisition circuit and then in series with the signal conditioning circuit. The signal monitoring circuit includes a first isolation circuit and a peak detection circuit. The first isolation circuit includes a voltage follower. The peak detection circuit includes an operational amplifier, a diode, and a capacitor. The signal acquisition circuit includes a second isolation circuit and a digital-to-analog converter (DAC) module. The DAC module includes multiple parallel-connected DACs with different ranges. Each DAC is connected in series with an electronic switch. The method includes: When the infrared detector detects the infrared signal of the object under test, the infrared signal is converted into a voltage signal; The voltage signal is input to the signal conditioning circuit so that the voltage signal is calibrated by the signal conditioning circuit to compensate for measurement errors; The calibrated voltage signal is input to the signal monitoring circuit so that the voltage signal is isolated by the first isolation circuit, and the peak detection circuit identifies the maximum voltage value in the isolated voltage signal. The analog-to-digital converter (ADC) matching the signal acquisition circuit is determined based on the range of the maximum voltage value, so as to switch the ADC of the signal acquisition circuit by controlling the closing of the electronic switch connected in series with the matching ADC; The voltage signal is input to the signal acquisition circuit so that the voltage signal is converted into a corresponding digital signal by the signal acquisition circuit; A grayscale value mapping function is determined based on the maximum voltage value and the digital signal, so as to convert the digital signal into image grayscale value data based on the grayscale value mapping function; A grayscale image of the object under test is generated based on the image grayscale value data.

2. The infrared channel low-temperature differential object imaging method according to claim 1, characterized in that, The infrared detector has a built-in first reference power supply, which includes a voltage reference chip. The method further includes: When the infrared detector is in a dark environment or does not detect the infrared signal of the object under test, voltage is supplied to the infrared detector through the first reference power supply; Record the output voltage of the infrared detector as a baseline offset; The offset error is calculated based on the output voltage and the preset reference voltage to calibrate the voltage signal of the infrared detector and compensate for the measurement error.

3. The infrared channel low-temperature differential object imaging method according to claim 1, characterized in that, The step of determining a grayscale value mapping function based on the maximum voltage value and the voltage signal, and converting the voltage signal into image grayscale value data based on the grayscale value mapping function, includes: When the voltage signal is within the range formed by the first voltage value and the second voltage value, the voltage signal is converted into image grayscale data by a preset logarithmic exchange function, wherein the first voltage value is less than the second voltage value, and the second voltage value is a first decimal multiple of the maximum voltage value; When the voltage signal is within the range formed by the second voltage value and the third voltage value, the voltage signal is converted into image grayscale data through a preset linear transformation function, wherein the second voltage value is less than the third voltage value, and the third voltage value is a second decimal multiple of the maximum voltage value; When the voltage signal is within the range formed by the third voltage value and the maximum voltage value, the voltage signal is converted into image grayscale data through a preset anti-logarithmic transformation function.

4. The infrared channel low-temperature differential object imaging method according to claim 1, characterized in that, The method further includes: Construct a neighborhood based on the grayscale image; Set the upper and lower threshold values ​​for the neighborhood; Traverse all pixels in the grayscale image to determine whether the grayscale value of each pixel is greater than the upper threshold or less than the lower threshold. Pixels with gray values ​​greater than the upper threshold or less than the lower threshold are identified as noise points, and noise points are removed.

5. The infrared channel low-temperature differential imaging method for objects according to claim 4, characterized in that, The setting of the upper and lower thresholds of the neighborhood includes the determination of the upper and lower thresholds according to formula (1): （1）， in, The upper limit threshold, The lower threshold value is... The average grayscale value of the pixels within the neighborhood. The standard deviation of the grayscale values ​​of the pixels within the neighborhood is given. It is a constant.

6. A device for imaging objects using infrared channel low-temperature difference imaging, characterized in that, include: The memory is configured to store instructions; The processor is configured to retrieve the instructions from the memory and, when executing the instructions, to implement the infrared channel cryogenic object imaging method according to any one of claims 1 to 5.

7. An infrared channel low-temperature difference object imaging circuit, characterized in that, include: An infrared detector, connected in series with a signal conditioning circuit, is used to convert the infrared signal into a voltage signal when the infrared signal of the object under test is detected. The signal conditioning circuit is used to calibrate the voltage signal to compensate for measurement errors; The signal monitoring circuit, connected in parallel with the signal acquisition circuit and then in series with the signal conditioning circuit, includes a first isolation circuit and a peak detection circuit. The first isolation circuit includes a voltage follower, and the peak detection circuit includes an operational amplifier, a diode, and a capacitor. The signal monitoring circuit is used to isolate the voltage signal through the first isolation circuit and to identify the maximum voltage value in the isolated voltage signal through the peak detection circuit. The signal acquisition circuit includes a second isolation circuit and a digital-to-analog conversion module. The digital-to-analog conversion module includes multiple parallel analog-to-digital converters with different ranges. Each analog-to-digital converter is connected in series with an electronic switch to convert the voltage signal into a corresponding digital signal. The apparatus for imaging objects with low temperature difference in infrared channel according to claim 6.

8. A machine-readable storage medium storing instructions thereon, characterized in that, When executed by a processor, this instruction causes the processor to be configured to perform the infrared channel cryogenic object imaging method according to any one of claims 1 to 5.

9. A computer program product, characterized in that, It includes a computer program that, when executed by a processor, implements the infrared channel cryogenic object imaging method as described in any one of claims 1 to 5.

Images