LCD display screen color correction system and method

Abstract

The invention relates to the technical field of display screen correction, in particular to an LCD display screen color correction system and method, and the method comprises the steps: dividing an LCD display screen into a plurality of independent correction subareas, and obtaining the display parameters of each correction subarea; based on the difference between the display parameter of each correction partition and a preset standard value, constructing a correction partition color difference compensation matrix, and fitting a linear compensation coefficient of the RGB channel through a least square method; smoothing the compensation matrixes of the adjacent correction partitions by adopting a bilinear interpolation algorithm to generate a global compensation mapping table; and dynamically acquiring the temperature of each correction subarea through a temperature sensor network, correcting the compensation matrix based on a thermal expansion coefficient model of the liquid crystal material, updating the global compensation mapping table, and inputting the updated global compensation mapping table into a storage unit of a display screen driving chip to complete correction. The problem that an existing global correction method cannot meet the production requirement for an ultra-large LCD display screen is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of display screen calibration, and particularly to an LCD display screen color calibration system and method. Background Art

[0002] An LCD display screen uses the electro-optical effect of liquid crystals to achieve image display. When there is no electric field, liquid crystal molecules will be arranged according to a certain rule, causing specific polarization and refraction phenomena when light passes through; when an electric field is applied, the arrangement direction of liquid crystal molecules changes, thus changing the propagation path and light transmission intensity of light.

[0003] During the production process of an extra-large LCD display screen (diagonal size exceeding 86 inches), color differences may occur in different regions due to factors such as poor uniformity of the backlight module and deviation of liquid crystal molecule orientation. The traditional global calibration method cannot adapt to the partition characteristics and does not consider the influence of temperature.

[0004] Therefore, the present invention provides an LCD display screen color calibration system and method to solve the above problems. Summary of the Invention

[0005] In view of the above situation, to overcome the defects of the prior art, the present invention provides an LCD display screen color calibration system and method, which solves the problem that the existing global calibration method cannot meet the production needs for extra-large LCD display screens.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] On the one hand, an LCD display screen color calibration method, the calibration method includes the following steps:

[0008] S100. Divide the LCD display screen into several independent calibration partitions, and obtain the display parameters of each calibration partition. The display parameters at least include the brightness value, chromaticity coordinates, and white balance deviation value of each calibration partition under a standard light source;

[0009] S200. Based on the difference between the display parameters of each calibration partition and the preset standard value, construct a calibration partition color difference compensation matrix, and fit the linear compensation coefficients of the RGB channels by the least square method;

[0010] S300. Use the bilinear interpolation algorithm to smooth the compensation matrix of adjacent calibration partitions to generate a global compensation mapping table;

[0011] S400. Dynamically obtain the temperature of each calibration partition through a temperature sensor network, correct the compensation matrix based on the thermal expansion coefficient model of the liquid crystal material and update the global compensation mapping table, and input the updated global compensation mapping table into the storage unit of the display screen driving chip to complete the calibration.

[0012] A further improvement of the present application is that in step S100, when dividing the LCD display screen into several independent calibration partitions, the following conditions should be met: the number of calibration partitions is proportional to the diagonal size of the LCD display screen, and the closer to the edge of the LCD display screen, the higher the calibration partition density, and the density gradient follows the formula:

[0013]

[0014] In expression (1), D0 represents the initial partition density of the central area of the LCD display screen, r represents the shortest distance from the center point of the current partition to the edge of the LCD display screen, and R is the equivalent radius of the LCD display screen.

[0015] A further improvement of the present application is that in step S100, the white balance deviation value is the relative deviation between the measured color temperature and the color temperature target value when the LCD display screen shows a pure white picture.

[0016] A further improvement of the present application is that after step S100, it also includes a secondary verification of the abnormal display parameters of the calibration partitions. The trigger condition for the secondary verification is: if the brightness standard deviation of any calibration partition exceeds the preset threshold, or the chromaticity coordinates exceed the sRGB color gamut range, then an automatic retest process is triggered until the data meets the confidence interval requirements.

[0017] A further improvement of the present application is that in step 200, the construction of the calibration partition color difference compensation matrix C i,j , includes:

[0018] S201. Determine the color difference ΔE of each calibration partition i,j , and the color difference of each calibration partition is determined by calculating through the CIEDE2000 formula;

[0019] S202. For each calibration partition (i, j), establish a mapping model between the RGB drive signals (R i,j , G i,j , B i,j ) and the color difference ΔE i,j , and the expression is:

[0020]

[0021] In expression (2), a1, a2, a3, b1, b2, b3, c represent the parameters to be fitted;

[0022] S203. Use the least squares method to solve the parameters to be fitted in the model in step S202, obtain the linear compensation coefficients of the RGB three channels, and construct the calibration partition color difference compensation matrix. The expression of the calibration partition color difference compensation matrix is:

[0023]

[0024] In expression (3), α i,j and γ i,j represent the gain coefficients of the channels, which are used to adjust the amplification ratio of the corresponding input signals, and β i,j and δ i,j represent the offsets of the channels, which are used to correct the static deviations of the corresponding components, and κ i,j represents the white balance compensation factor, which is used to adjust the color temperature consistency of the channels.

[0025] A further improvement of the present application lies in that in step S300, a bilinear interpolation algorithm is used to smooth the compensation matrix of adjacent calibration partitions, including:

[0026] S301. Obtain any pixel point (x, y) in the screen of any calibration partition of the LCD display screen, determine the compensation matrices C i,j , C i+1,j , C i,j+1 , C i+1,j+1 of its four adjacent partitions, and calculate the horizontal interpolation weight and the vertical interpolation weight according to the relative position of the pixel point (x, y) within the partition, and determine the compensation value of the pixel point;

[0027] S302. If the pixel point is located at the edge of the screen and has no adjacent partitions, the mirror filling method is used to expand the compensation matrix;

[0028] S303. For the regions where gradient mutations still exist after interpolation in steps S301 and S302, a Gaussian filter kernel is superimposed to smooth the color levels until the gradient mutations remaining after interpolation are eliminated.

[0029] A further improvement of the present application lies in that in step S400, the temperature of each calibration partition is dynamically obtained through the temperature sensor network, and the compensation matrix is corrected based on the thermal expansion coefficient model of the liquid crystal material, including:

[0030] S401. Obtain the temperature T i,j of each calibration partition, and construct a temperature data model in which the temperature changes with time. The expression of the temperature data model is:

[0031]

[0032] In expression (4), T0 represents the initial temperature of the display screen in a stable environment; ΔT k represents the increment of the kth temperature change, τ is the thermal inertia time constant, which represents the attenuation rate of the temperature change, t is the time variable, which represents the time interval from the occurrence of the temperature change to the current moment;

[0033] S402. Obtain the pre-stored liquid crystal material parameter table and adjust the compensation matrix. The expression of the adjusted compensation matrix is:

[0034]

[0035] In expression (5), C i,j represents the original compensation matrix, obtained through expression (3). ⊙ represents the Hadamard product. ΔT = T i,j - T0 represents the difference between the current temperature and the reference temperature. k R, k G, k B represents the temperature drift coefficient of the corresponding channel. ΔC LC (T) represents the cross compensation term caused by the change of the liquid crystal refractive index.

[0036] A further improvement of the present application lies in that in step 402, the pre-stored liquid crystal material parameters include: the temperature drift coefficients of the corresponding channels of the RGB channels, which are used to compensate for the decrease in backlight efficiency or the response delay of liquid crystal molecules caused by temperature increase; the refractive index temperature coefficient of the liquid crystal material, which is used to correct the change of the optical characteristics of the liquid crystal layer caused by temperature change; and the backlight brightness attenuation factor, which is used to dynamically adjust the backlight brightness and suppress the brightness decrease at high temperatures.

[0037] On the other hand, an LCD display color correction system is characterized by including: at least one processor; and a memory communicatively connected to the at least one processor; wherein, the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method described in any one of the above.

[0038] The beneficial effects of the present invention are as follows: Through zonal correction and temperature compensation, precise color correction of an ultra-large LCD display is achieved, and the problems that the traditional global correction method cannot adapt to zonal characteristics and does not consider the influence of temperature are solved. The correction method of the present invention not only improves the correction accuracy, the zonal accuracy is increased by 300% compared with the traditional method, and the JNCD value is less than 0.5, but also can adapt to the temperature change of the display screen in real time, and suppress the thermochromic drift to within ±2% through temperature compensation, thereby ensuring the stability and consistency of the display effect. In addition, the correction efficiency is improved, and the single-screen processing time is controlled within 10 minutes. Description of the Drawings

[0039] Figure 1 is a schematic flow chart of a method for color correction of an LCD display according to the present invention;

[0040] Figure 2 is a schematic structural diagram of a color correction system for an LCD display according to the present invention. Detailed Embodiments

[0041] The following will describe the embodiments of the present invention in detail with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0042] Ultra-large size LCD generally refers to a display screen with a diagonal size exceeding 86 inches, which is mainly used in commercial, public display, and high-end consumer scenarios. During the production of ultra-large size LCD display screens, the inventor found that ultra-large size LCD display screens are prone to color differences in different regions due to factors such as poor uniformity of the backlight module and deviation of liquid crystal molecule orientation. If the traditional global correction method is used, it can no longer adapt to the partition characteristics, resulting in low correction efficiency. Moreover, the traditional global correction method does not consider the influence of temperature, resulting in unsatisfactory color correction effects.

[0043] Based on the above problems, the inventor provided the following solutions:

[0044] 1. Partition acquisition: Divide the ultra-large LCD screen into multiple regions and collect the display data of each region separately.

[0045] 2. Optical calibration: Use a high-precision sensor to measure parameters such as brightness, chromaticity, and uniformity of each region.

[0046] 3. Dynamic compensation algorithm: Calculate the compensation coefficient of each region according to the measured data and adjust the driving signal.

[0047] 4. Temperature compensation: Considering the temperature change during the operation of the large screen, a temperature sensor may be added for real-time adjustment.

[0048] 5. Store calibration parameters: Store the calibration parameters of each region in the firmware of the display screen to ensure consistency after leaving the factory.

[0049] In view of the above problems, the present application provides a method for color correction of an LCD display screen, and the correction method includes the following steps:

[0050] S100. Divide the LCD display screen into several independent calibration partitions, and obtain the display parameters of each calibration partition. The display parameters at least include the brightness value, chromaticity coordinates, and white balance deviation value of each calibration partition under a standard light source;

[0051] S200. Based on the difference between the display parameters of each calibration partition and the preset standard value, construct a color difference compensation matrix for the calibration partition, and fit the linear compensation coefficients of the RGB channels by the least squares method;

[0052] S300. Use the bilinear interpolation algorithm to smooth the compensation matrix of adjacent calibration partitions to generate a global compensation mapping table;

[0053] S400. Dynamically obtain the temperature of each calibration partition through a temperature sensor network, correct the compensation matrix based on the thermal expansion coefficient model of the liquid crystal material, update the global compensation mapping table, and input the updated global compensation mapping table into the storage unit of the display driver chip to complete the calibration.

[0054] Next, specific embodiments will be combined to describe the technical solution in detail.

[0055] Embodiment

[0056] Reference Figure 1 , an LCD display color calibration method, the calibration method includes the following steps:

[0057] S100. Divide the LCD display into N×M independent calibration partitions, and obtain the display parameters of each calibration partition. The display parameters at least include the brightness value L of each calibration partition under a standard light source i,j , chromaticity coordinates (x i,j , y i,j ) and white balance deviation value ΔW i,j ;

[0058] S200. Based on the difference between the display parameters of each calibration partition and the preset standard value, construct a calibration partition color difference compensation matrix C i,j , and fit the linear compensation coefficients of the RGB channels by the least squares method;

[0059] S300. Use the bilinear interpolation algorithm to smooth the compensation matrix of adjacent calibration partitions to generate a global compensation mapping table;

[0060] S400. Dynamically obtain the temperature T of each calibration partition through a temperature sensor network, correct the compensation matrix based on the thermal expansion coefficient model of the liquid crystal material, update the global compensation mapping table, and input the updated global compensation mapping table into the storage unit of the display driver chip to complete the calibration. i,j

[0061] In an embodiment of the present application, in step S100, when dividing the LCD display (taking an 86-inch rectangular screen as an example) into N×M (such as 24×36 partitions) independent calibration partitions, the following conditions should be met: the number of calibration partitions N×M is proportional to the diagonal size of the LCD display, and the closer to the edge of the LCD display, the higher the calibration partition density, and the density gradient follows the formula:

[0062]

[0063] In expression (1), D0 represents the initial partition density of the central area of the LCD display screen, r represents the shortest distance from the center point of the current partition to the edge of the LCD display screen, and R is the equivalent radius of the LCD display screen (109.16 cm).

[0064] Through expression (1), sparse partitioning in the central area reduces the computational amount. The overall number of partitions only increases by about 30%, but the calibration effect is improved by more than 50%. The gradient formula can adapt to different screen sizes. Only D0 and R need to be adjusted, and there is no need to redesign the algorithm.

[0065] Specifically, during operation, a D65 light source compliant with the ISO3664:2009 standard is deployed as the reference illumination in a darkroom environment. The color temperature of the light source is set to 6500K ± 50K, and the illuminance uniformity ≥ 95%. The N×M partitions divided are scanned zone by zone through a multispectral imager. The spectral resolution of the multispectral imager ≤ 5 nm, and the spatial resolution matches the pixel density of a single partition. Among them, the brightness value of the calibration partition under the standard light source i,j , is obtained by measuring the brightness at the center point and the four corner points of the partition through a photometric probe and taking the arithmetic mean; the chromaticity coordinates (x i,j , y i,j ) are obtained by getting the tristimulus values X i,j , Y i,j , Z i,j through a spectroradiometer, and are calculated according to the formula: The white balance deviation value ΔW i,j is the relative deviation between the measured color temperature T measured and the color temperature target value T target (6500K) when the LCD display screen shows a pure white picture (RGB = 255, 255, 255). The calculation formula is:

[0066] To ensure the accuracy of the data collected for each calibration partition, after step S100, it also includes a secondary verification of the abnormal display parameters of the calibration partition. The trigger condition for the secondary verification is: if the brightness standard deviation of any calibration partition exceeds the preset threshold (≥ 10%), or the chromaticity coordinates exceed the sRGB color gamut range, then the automatic retest process is triggered until the data meets the confidence interval requirements.

[0067] In an embodiment of the present application, in step 200, the construction of the calibration partition color difference compensation matrix C i,j , includes:

[0068] S201. Determine the color difference ΔE i,j of each calibration partition. The color difference of each calibration partition is determined by calculating through the CIEDE2000 formula;

[0069] S202. For each calibration partition (i, j), establish a mapping model between the RGB drive signals (R i,j , G i,j , B i,j ) and the color difference ΔE i,j through a gradient experiment (the RGB drive signals are adjusted within the range of ±10%), and the expression is:

[0070]

[0071] In expression (2), a1, a2, a3, b1, b2, b3, c represent the parameters to be fitted;

[0072] S203. Use the least squares method to solve the parameters to be fitted in the model in step S202, obtain the linear compensation coefficients of the RGB three channels, and construct a calibration partition color difference compensation matrix. The expression of the calibration partition color difference compensation matrix is:

[0073]

[0074] In expression (3), α i,j , γ i,j represent the gain coefficients of the channels, used to adjust the amplification ratio of the input corresponding signals, β i,j , δ i,j represent the offsets of the channels, used to correct the static deviation of the corresponding components, and κ i,j represents the white balance compensation factor, used to adjust the color temperature consistency of the channels.

[0075] In step S203, the value of κ i,j is determined by linear interpolation through ΔW i,j , and the calculation formula is as follows: Where, ΔW max is the preset maximum allowable white balance deviation.

[0076] In an embodiment of the present application, since the compensation matrix mentioned in step S200 is for each partition, each partition may have different calibration parameters. However, the display screen is a continuous display area. If the compensation parameters of each partition are directly used at the boundaries between partitions, obvious color or brightness mutations may occur, resulting in visual discontinuity, such as color blocks or bright and dark bands. At this time, it is necessary to make the parameters of adjacent partitions transition smoothly to avoid such mutations.

[0077] Preferably, in step S300, a bilinear interpolation algorithm is used to smooth the compensation matrix of adjacent calibration partitions, including:

[0078] S301. Obtain any pixel point (x, y) on the screen of any calibration partition of the LCD display screen, and determine the compensation matrices C of its four adjacent partitionsi,j , C i+1,j , C i,j+1 , C i+1,j+1 , where and calculate the horizontal interpolation weight u and the vertical interpolation weight v according to the relative position of the pixel point (x, y) within the partition, where u = x - i, v = y - j (0 ≤ u, v < 1), and determine the compensation value C(x, y) of the pixel point. The compensation value C(x, y) is obtained through the following expression

[0079] C(x, y) = (1 - u)(1 - v)C i,j + u(1 - v)C i+1,j +(1 - u)vC i,j+1 + uvC i+1,j+1 , ;

[0080] S302. If the pixel point is located at the screen edge and there is no adjacent partition, then use the mirror filling method to expand the compensation matrix. The formula is: C N+1,j = C N-1,j , C i,M+1 = C i,M-1 ;

[0081] S303. For the area where gradient mutation still exists after interpolation in steps S301 and S302, then superimpose a Gaussian filter kernel (σ = 0.5) to smooth the color level until the gradient mutation remaining after interpolation is eliminated.

[0082] Through the above steps S301 - S303, the weight calculation and matrix operation rules of bilinear interpolation are clearly defined by mathematical formulas to ensure smooth transition of the compensation value. The introduction of mirror filling and Gaussian filtering avoids color level breakage caused by data loss at the screen edge.

[0083] In an embodiment of the present application, since the refractive index and backlight brightness of the liquid crystal material in the LCD screen may change at different temperatures, resulting in color difference. Therefore, temperature compensation needs to adjust the compensation parameters according to the real - time temperature to offset the influence of temperature on the display effect. Based on the above - mentioned embodiment, in step S400, the temperature T of each calibration partition is dynamically obtained through the temperature sensor network i,j , and the compensation matrix is corrected based on the thermal expansion coefficient model of the liquid crystal material, including:

[0084] S401. Obtain the temperature T of each calibration partition i,j , and construct a temperature data model in which the temperature changes with time. The expression of the temperature data model is:

[0085]

[0086] In expression (4), T0 represents the initial temperature of the display screen in a stable environment; ΔT k represents the increment of the k-th temperature change, τ is the thermal inertia time constant (unit: second), representing the attenuation rate of the temperature change, t is the time variable (unit: second), representing the time interval from the occurrence of the temperature change to the current moment;

[0087] During actual testing, a PT1000 thin-film temperature sensor array is evenly arranged on the backplane of the LCD screen, and the sensor spacing ≤ 5 cm to ensure that each calibration partition contains at least 1 sensor; and the temperature T of each partition is collected in real time at a sampling rate of 100 Hz through a multiplexer i,j ; Usually, T0 is set to 25 °C. Specifically, under the condition that the display screen is operating stably and without load (such as standing still for 30 minutes after initial startup), the temperature at multiple time points is measured through the temperature sensor array, and the average value is taken as the reference temperature; τ is set to 10 seconds. Specifically, a known thermal perturbation is applied to the display screen (such as turning on the backlight to the maximum brightness), and the curve of the temperature decreasing with time is recorded; the exponential decay model T(t) = T0 + ΔT·e -t / τ is used to fit the data and solve for τ.

[0088] S402. Obtain the pre-stored liquid crystal material parameter table and adjust the compensation matrix. The expression of the adjusted compensation matrix is:

[0089]

[0090] In expression (5), C i,j represents the original compensation matrix, obtained through expression (3), ⊙ represents the Hadamard product, ΔT = T i,j - T0 represents the difference between the current temperature and the reference temperature, k R, k G, k B represents the temperature drift coefficient of the corresponding channel, and ΔC LC (T) represents the cross compensation term caused by the change of the liquid crystal refractive index.

[0091] Specifically, ΔC LC (T) is obtained through ;

[0092] Preferably, in step 402, the pre-stored liquid crystal material parameters include:

[0093] The temperature drift coefficients of the corresponding channels of the RGB channels, that is, k R, k G, k B(Unit: % / °C), which is used to compensate for the decrease in backlight efficiency or the delay in liquid crystal molecule response caused by temperature increase, indicating the proportion of gain adjustment required for the corresponding color channel for every 1°C increase in temperature;

[0094] During specific operation, in the temperature control box, gradually increase the display screen temperature from T0 to the maximum threshold (such as 50°C), record the brightness values of the RGB channels at each temperature point, and through linear regression analysis, calculate the slope of the gain change with temperature, that is, the temperature drift coefficient.

[0095] The refractive index temperature coefficient of the liquid crystal material, that is (Unit: 1 / °C), which is used to correct the change in the optical properties of the liquid crystal layer (such as color shift) caused by temperature change, indicating the rate of change of the refractive index with temperature. For example, the change in refractive index will change the light transmittance;

[0096] Specifically, use an ellipsometer to measure the refractive index n(T) of the liquid crystal material at different temperatures, and fit the linear relationship

[0097] and the backlight brightness attenuation factor α BL (Unit: 1 / °C), which represents the attenuation rate of the backlight brightness with the increase in temperature, and is used to dynamically adjust the backlight brightness to suppress the brightness decrease at high temperatures.

[0098] Specifically, under a constant drive current, measure the output brightness L(T) of the backlight module at different temperatures (such as 20°C - 60°C), and fit the exponential decay model Solve for α BL .

[0099] Compared with the prior art, the LCD display color correction method of the present application significantly improves the correction accuracy and display effect by comprehensively considering multiple aspects such as zonal correction, color difference compensation, smoothing processing, and temperature compensation. In the zonal correction stage, the sparse zonal strategy in the central area is adopted, effectively reducing the calculation amount while ensuring a substantial improvement in the correction effect. The construction of the color difference compensation matrix is based on the accurate measurement and model fitting of the color differences in each correction zone, realizing the accurate mapping between the RGB drive signals and the color differences.

[0100] Furthermore, the compensation matrix of adjacent correction zones is smoothed through the bilinear interpolation algorithm, effectively avoiding sudden changes in color or brightness and ensuring visual continuity. In addition, for the edge area of the screen, the mirror filling method is used to expand the compensation matrix, and a Gaussian filter kernel is superimposed on the area where there are still gradient mutations after interpolation for smooth color level processing, thereby further improving the correction effect.

[0101] In terms of temperature compensation, the present application dynamically obtains the temperature of each calibration area through a temperature sensor network, and corrects and compensates the matrix based on the thermal expansion coefficient model of the liquid crystal material, effectively canceling out the influence of temperature on the display effect. This improves the adaptability of the calibration system and ensures excellent display effects in different temperature environments.

[0102] In summary, the LCD display color calibration method of the present application has significant advantages such as high calibration accuracy, excellent display effect, and strong adaptability, providing a new solution for the color calibration of LCD displays.

[0103] Reference Figure 2 , an LCD display color calibration system, comprising:

[0104] At least one processor;

[0105] And a memory communicatively connected to the at least one processor; wherein,

[0106] The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method described in the above embodiments.

[0107] The various embodiments of the systems and techniques described above in this document can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SOCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include: implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a dedicated or general-purpose programmable processor, and can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit the data and instructions to the storage system, the at least one input device, and the at least one output device.

[0108] The program code for implementing the methods of the present disclosure can be written in any combination of one or more programming languages. These program codes can be provided to the processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing devices, such that when the program codes are executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The program codes can be executed entirely on the machine, partially on the machine, executed partially on the machine as an independent software package and partially on a remote machine, or executed entirely on a remote machine or server.

[0109] In the context of this disclosure, a machine-readable medium can be a tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0110] To provide for interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the computer. Other kinds of devices can also be used to provide for interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic, speech, or tactile input).

[0111] The systems and techniques described herein can be implemented in a computing system that includes a back-end component (e.g., as a data server), or a computing system that includes a middleware component (e.g., an application server), or a computing system that includes a front-end component (e.g., a user computer having a graphical user interface or a web browser through which the user can interact with an implementation of the systems and techniques described herein), or a computing system that includes any combination of such back-end, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of a communication network include: a local area network (LAN), a wide area network (WAN), and the Internet.

[0112] A computer system may include a client and a server. The client and the server are generally far from each other and usually interact through a communication network. The relationship between the client and the server is generated by computer programs running on the respective computers and having a client-server relationship with each other. The server may be a cloud server, or a server of a distributed system, or a server incorporating a blockchain.

[0113] It should be understood that various forms of the processes shown above can be used, steps can be reordered, added, or deleted. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and no limitations are imposed herein.

[0114] The above specific embodiments do not constitute a limitation on the protection scope of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure shall be included within the protection scope of this disclosure.

Claims

1. A method for color correction of an LCD display screen, characterized in that: The calibration method comprises the following steps: S100, dividing the LCD display screen into a plurality of independent correction partitions, and obtaining display parameters of each correction partition, wherein the display parameters at least include brightness values, chromaticity coordinates, and white balance deviation values ​​of each correction partition under a standard light source; S200, constructing a color difference compensation matrix for the correction partitions based on the differences between the display parameters of each correction partition and the preset standard values, and fitting the linear compensation coefficients of the RGB channels by the least square method; S300, using a bilinear interpolation algorithm to smooth the compensation matrices of adjacent correction partitions to generate a global compensation mapping table; S400, dynamically acquiring the temperature of each correction partition through a temperature sensor network, correcting the compensation matrix based on a thermal expansion coefficient model of the liquid crystal material and updating the global compensation mapping table, inputting the updated global compensation mapping table into a storage unit of a display driver chip to complete the correction.

2. The method for color correction of an LCD display screen according to claim 1, characterized in that: In step S100, the LCD display screen is divided into a number of independent correction partitions, which should meet the following conditions: the number of correction partitions is proportional to the diagonal size of the LCD display screen, and the closer to the edge of the LCD display screen, the higher the correction partition density, and the density gradient follows the formula: In expression (1), D0 represents the initial partition density of the central area of ​​the LCD display screen, r represents the shortest distance from the center point of the current partition to the edge of the LCD display screen, and R is the equivalent radius of the LCD display screen.

3. The LCD display screen color correction method according to claim 1, characterized in that: In step S100, the white balance deviation value is the relative deviation between the measured color temperature and the target color temperature when the LCD display screen displays a pure white picture.

4. The LCD display screen color correction method according to claim 1, characterized in that: After step S100, a secondary verification of the abnormal display parameters of the correction partition is also included. The triggering condition of the secondary verification is: if the brightness standard deviation of any correction partition exceeds a preset threshold, or the chromaticity coordinates exceed the sRGB color gamut, an automatic re-test process is triggered until the data meets the confidence interval requirements.

5. The LCD display screen color correction method according to claim 1, characterized in that: In step 200, the correction partition chromatic aberration compensation matrix C is constructed. i,j ,include: S201, determining the color difference ΔE of each correction partition i,j , the color difference of each correction partition is calculated and determined by CIEDE2000 formula; S202: For each calibration partition (i, j), establish an RGB drive signal (R i,j ,G i,j ,B i,j ) and color difference ΔE i,j The mapping model is expressed as: In expression (2), a1, a2, a3, b1, b2, b3, c represent the parameters to be fitted; S203, using the least square method to solve the parameters to be fitted in the model in step S202, obtain the linear compensation coefficients of the three channels of RGB, and construct a correction partition chromatic aberration compensation matrix, the expression of which is: In expression (3), α i,j , γ i,j Indicates the gain coefficient of the channel, which is used to adjust the amplification ratio of the input corresponding signal, β i,j , δ i,j Represents the offset of the channel, which is used to correct the static deviation of the corresponding component, κ i,j Represents the white balance compensation factor, which is used to adjust the color temperature consistency of the channel.

6. The method for color correction of an LCD display screen according to claim 5, characterized in that: In step S300, a bilinear interpolation algorithm is used to smooth the compensation matrices of adjacent correction partitions, including: S301, obtain any pixel point (x, y) in any correction partition screen of the LCD display screen, and determine the compensation matrix C of the four adjacent partitions to which it belongs i,j ,C i+1,j ,C i,j+1 ,C i+1,j+1 , and according to the relative position of the pixel point (x, y) in the partition, calculate the horizontal interpolation weight and the vertical interpolation weight, and determine the compensation value of the pixel point; S302: If the pixel point is located at the edge of the screen and has no adjacent partition, a mirror filling method is used to expand the compensation matrix; S303 , for areas where there are still sudden gradient changes after interpolation in steps S301 and S302 , a Gaussian filter kernel is superimposed to smooth the color scale until the sudden gradient changes remaining after interpolation are eliminated.

7. The method for color correction of an LCD display screen according to claim 5, characterized in that: In step S400, the temperature of each correction zone is dynamically acquired through a temperature sensor network, and the compensation matrix is ​​corrected based on a thermal expansion coefficient model of a liquid crystal material, including: S401, obtaining the temperature T of each calibration partition i,j , and build a temperature data model of temperature changing with time. The expression of the temperature data model is: In expression (4), T0 represents the initial temperature of the display screen under a stable environment; ΔT k represents the increment of the kth temperature change, τ is the thermal inertia time constant, which represents the decay rate of the temperature change, and t is the time variable, which represents the time interval from the occurrence of the temperature change to the current moment; S402, obtaining a pre-stored liquid crystal material parameter table, and adjusting the compensation matrix, wherein the expression of the adjusted compensation matrix is: In expression (5), C i,j represents the original compensation matrix, obtained by expression (3), ⊙ represents the Hadamard product, ΔT = T i,j -T0 represents the difference between the current temperature and the reference temperature, k R ,k G ,k B Indicates the temperature drift coefficient of the corresponding channel, ΔC LC (T) represents the cross compensation term caused by the change of the refractive index of the liquid crystal.

8. The method for color correction of an LCD display screen according to claim 7, characterized in that: In step 402, the pre-stored liquid crystal material parameters include: The temperature drift coefficient of the RGB channels corresponding to the channels is used to compensate for the decrease in backlight efficiency or the response delay of liquid crystal molecules caused by the increase in temperature; The temperature coefficient of the refractive index of the liquid crystal material is used to correct the changes in the optical properties of the liquid crystal layer caused by temperature changes; And the backlight brightness attenuation factor is used to dynamically adjust the backlight brightness and suppress the brightness drop at high temperatures.

9. A color correction system for an LCD display screen, characterized in that: include: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 8.

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