Method and System for Measuring Maximum Halo of a Mini-LED Zoned Backlight Display Screen

Abstract

The present invention discloses a method and system for measuring the maximum halo of a Mini-LED zoned backlight display screen. Specifically, it includes the following steps: First, build a halo measurement device in a dark environment. Second, use the optimal display white box size optimization method to find the display white box size corresponding to the maximum brightness of the display white box. Then, use the optimal display white box position optimization module to find the display white box position corresponding to the maximum halo width of the display white box. Next, measure the maximum halo effect found in the dark environment. Finally, simulate and reproduce the two-dimensional halo field distribution to obtain the maximum halo brightness and maximum halo width corresponding to the halo effect. After adopting the method of the present invention, the maximum halo situation of any Mini-LED display screen can be found and measured, and at the same time, the static halo is quantitatively analyzed, thereby effectively improving the precision and accuracy of the halo effect test of the Mini-LED display screen.

Description

Technical Field

[0001] The present invention relates to the technical field of display screen detection, and specifically to a method and system for measuring the maximum halo of a Mini-LED zoned backlight display screen. Background Art

[0002] Display technology is one of the important means for us to express and obtain information. With the continuous development and progress of display technology in recent years, consumers' pursuit of display quality has become higher and higher, and Mini-LED backlight technology has become a research hotspot in the current display field. With its size advantage, smaller and denser LED beads are used to replace the traditional backlight source, enabling thousands of zoned dimming, and it can also be combined with quantum dot technology to greatly improve the performance of the display screen such as contrast and color gamut. At the same time, Mini-LED backlight technology has been widely commercialized in many fields such as televisions, laptop computers, and in-vehicle displays. Zoned dimming divides the backlight area into multiple independent dimming segments to achieve independent brightness and extinction for each local dimming area. This method can better match the brightness required for the displayed image in each area, thereby achieving HDR display, while also effectively reducing power consumption and extending the display life of the monitor.

[0003] However, there are still some problems in further improving the local dimming performance of Mini-LED display screens. The halo phenomenon is a major problem that reduces the image display quality of Mini-LEDs. Therefore, in order to be able to specifically measure and quantify the most severe degree of halo that will exist when different display screens display images, a method for measuring the maximum static halo of Mini-LED display screens urgently needs to be developed. Summary of the Invention

[0004] Object of the Invention: Aiming at the above problems, the first object of the present invention is to provide a method for measuring the maximum halo of a Mini-LED zoned backlight display screen, which can find the most severe situation of the halo effect of the display screen and measure the halo effect, and has good versatility.

[0005] The second object of the present invention is to provide a system for measuring the maximum halo of a Mini-LED zoned backlight display screen.

[0006] Technical Solution: To achieve the above objects, the present invention discloses a method for measuring the maximum halo of a Mini-LED zoned backlight display screen, specifically including the following steps:

[0007] (1) Build a halo measurement device in a dark environment;

[0008] (2) Measure the brightness of the white box area displayed on the Mini-LED zoned backlight display screen in the darkroom environment, and iteratively measure the brightness corresponding to different-sized display white boxes to finally obtain the size of the display white box corresponding to the maximum display white box brightness.

[0009] (3) After determining the size of the display white box, perform pixel-level movement on the white box with the determined size and measure the halo situation. Measure the halos of white boxes at different positions on the Mini-LED zoned backlight display screen in a darkroom environment, and determine the position of the white box corresponding to the maximum halo width;

[0010] (4) After determining the size and position of the display white box, perform masking on the display white box area and use an imaging luminance meter to take pictures and measure to obtain the halo brightness distribution in a darkroom environment;

[0011] (5) According to the obtained halo brightness data in the darkroom environment, simulate and reproduce the halo to obtain the two-dimensional field distribution formula of the halo, and inversely deduce the maximum halo brightness parameter and the maximum halo width parameter through the formula to complete the maximum halo measurement.

[0012] Among them, step (1) specifically includes the following steps:

[0013] (1.1) Construction of the darkroom environment. Since the brightness value of the halo is very small, in order to avoid the influence of stray light, the halo measurement experiment needs to be carried out in a darkroom environment, and at the same time, it is necessary to ensure that the surface brightness of objects in the darkroom environment is less than 0.001 cd / m 2 , and except for the Mini-LED backlight display screen, the rest of the light-emitting bodies need to be blocked with light-impermeable and non-reflective black cloth;

[0014] (1.2) Construction of the halo measurement device. The halo measurement device includes a test platform with sufficient length and width, a Mini-LED zoned backlight display screen, a host for transmitting the image source to the Mini-LED zoned backlight display screen, an imaging luminance meter for measuring the zoned backlight display screen and related fixing devices, and a host for outputting the halo brightness distribution data. Among them, place the Mini-LED zoned backlight display screen to be measured at one end of the test platform, fix the imaging luminance meter on the cloud platform and place it at the other end of the platform, and place it in a suitable position so that the Mini-LED zoned backlight display screen to be measured appears completely and clearly in the field of view captured by the imaging luminance meter;

[0015] (1.3) Ensure the display state of the screen to be measured. The Mini-LED zoned backlight display screen needs to turn on the zoned backlight setting and the HDR mode, and at the same time, the brightness and contrast parameters need to be set to Max to ensure that the Mini-LED zoned backlight display screen can reach the maximum halo state. At the same time, the device to be measured needs to be preheated for 30 minutes before measurement, and a white screen with the maximum brightness is used to preheat the Mini-LED zoned backlight display screen to be measured during the preheating period;

[0016] (1.4) Assurance of test equipment performance. The resolution of the imaging luminance meter used in the test should be greater than the resolution of the display area to be measured, so as to ensure that the luminance of each pixel can be accurately measured. The resolution of the imaging luminance meter is greater than the resolution of the display screen to be measured, so as to ensure that the luminance of each pixel point on the display screen to be measured can be accurately measured. If the resolution of the imaging luminance meter is less than the resolution of the display screen to be measured, the luminance difference between different pixel points cannot be measured;

[0017] (1.5) Focus the imaging luminance meter on the Mini-LED zoned backlight display screen to be measured. Manually adjust the focus ring of the imaging luminance meter until the image of the Mini-LED zoned backlight display screen to be measured can be clearly presented in the image of the imaging luminance meter, then the focusing is completed.

[0018] Preferably, step (2) specifically includes the following steps:

[0019] (2.1) It is known that the maximum luminance of the white box displayed on the Mini-LED zoned backlight display screen shows a trend of first increasing and then decreasing as the ratio of the side length of the white box to the size of the display screen increases. This also means that there is a maximum luminance when the white box on the screen occupies a certain proportion of the corresponding light-emitting area, and the maximum luminance of the light-emitting area also corresponds to the maximum luminance of the halo. Therefore, a method for finding the maximum luminance of the white box displayed on the screen is designed: Let the resolution of the Mini-LED zoned backlight display screen to be measured be W Max and H Max , set the initial sizes W0 and H0 of the white box to be W Max / 100 and H Max / 100 respectively; set the growth steps ΔW and ΔH of the length and width of the white box to be W Max / 100 and H Max / 100 respectively; the initial display position of the white box is the center position of the display screen, the gray level of the white box is full gray level, and the gray level of other areas of the display screen is 0; set the initial value of the iteration number T to 0;

[0020] (2.2) The imaging luminance meter measures the luminance values of all pixel points on the Mini-LED zoned backlight display screen when the white box with the initial size is displayed in a dark room environment. Process the luminance values of all pixel points on the display screen, and extract the luminance values of all pixel points in the area where the white box is displayed on the display screen. There are glare and halos around the area where the white box is displayed, obtain the luminance distribution of the backlight display screen when the light-emitting area of the Mini-LED zoned backlight display screen is not blocked, and record the maximum luminance as L 0_Max , and at the same time, increment the iteration number T by one. At this time, it is regarded as completing the first measurement;

[0021] (2.3) After completing the first measurement, the control program changes the display white box size on the display screen. At this time, the size of the display white box is W1 and H1, where the values of W1 and H1 are W0 + ΔW and H0 + ΔH respectively; and repeat the same measurement steps as in step (2.2), and obtain the maximum brightness L corresponding to the white box sizes of W1 and H1 1_Max , and this is regarded as completing the second measurement; at this time, make a judgment: if L 1_Max > L 0_Max , then continue to execute the iteration and conduct the test; if L 1_Max < L 0_Max , then stop the iteration, and L 0_Max is the maximum brightness of the corresponding display screen, and W0 and H0 are the corresponding sizes of the display white box;

[0022] (2.4) Continuously execute the iteration and judgment. When the nth measurement occurs, where L 0_Max < L 1_Max < L 2_Max < L 3_Max <... < L n_Max < L n+1_Max < L n+2_Max <..., then stop the iteration, and L n_Max is the maximum brightness of the corresponding display screen, and W n and H n are the corresponding sizes of the display white box, where W n and H n are W0 + n·ΔW and H0 + n·ΔH respectively.

[0023] Preferably, step (3) specifically includes the following steps:

[0024] (3.1)Based on the white box with the same size being displayed, the halo effect depends on the position of the white box relative to the backlight zone unit (BLU). When the white box coincides with the backlight zone unit, the halo effect is the best at this time, that is, the halo is the least obvious; when the white box just lights up a certain backlight zone unit, the halo effect is the worst at this time, and it also corresponds to the maximum halo width on one side in a certain direction. Then when the white box moves on the display screen, when the white box just moves to a new zone, the backlight of this zone is lit, and at this time the halo width on this side in this direction will increase sharply. At this time, it corresponds to the halo width in the worst case of the halo effect on this side in this direction. As the white box continues to move in this direction, the halo width is limited by the edge of the white box to the boundary of this zone and the halo width gradually decreases. Therefore, the halo effect of the display screen needs to be measured under the worst case of the halo effect. Therefore, a method for finding the maximum halo of the screen display white box is designed: assume that the size of the backlight zone of the Mini-LED zone backlight display screen is a pixel points, and it is set that the white box moves first in the horizontal X direction. Let the initial position of the white box be the center position of the display screen, and the coordinates (x0, y0) of its upper left pixel are (W Max / 2 - W n , H Max / 2 - H n ). Set the movement step sizes of the white box as Δx and Δy to be a / 10; the gray level of the white box is full gray level, and the gray level of other areas of the display screen is 0; set the number of iterations T x The initial value is 0;

[0025] (3.2) The imaging luminance meter measures the luminance values of all pixel points on the screen when the coordinates of the upper left pixel of the white box on the Mini-LED zone backlight display screen are in the situation of (x0, y0) in a dark room environment, processes the luminance values of all pixel points on the display screen, extracts the luminance values of the halo around the area of the white box on the display screen, and extracts the luminance values in a single direction of the halo to obtain the luminance distribution in a single direction of the halo, and calculates that the pixel distance between the point with the maximum halo luminance value and the 0.001 cd / m 2 luminance value point is the halo width denoted as D x_0 , and at the same time the number of iterations T x is incremented by one. At this time, it is regarded as completing the first measurement;

[0026] (3.3) After completing the first measurement, control the white box on the screen to move one step in the horizontal direction. At this time, the coordinates of the upper left pixel of the white box are (x1, y0), where the values of x1 and y0 are x0 + Δx and y0 respectively; and repeat the same measurement steps as in step (3.2), and obtain the corresponding halo width D x_1 on this side when the upper left coordinates of the white box are (x1, y0). At this time, it is regarded as completing the second measurement; at this time, a judgment is made: if Dx_1 <D x_0 , continue to perform iteration and conduct tests; if D x_1 >D x_0 and there is a sharp increase in the halo width on this side, stop the iteration, D x_1 is the maximum halo width of the corresponding display screen, and (x1, y0) is the pixel coordinates of the upper left corner corresponding to the display white box;

[0027] (3.4) Continuously perform iteration and judgment. When the nth measurement occurs, where D x_0 >D x_1 >D x_2 >D x_3 >……>D x_n-1 <D x_n >D x_n+1 >D x_n+2 >……, at the nth measurement, if there is a sharp increase in the halo width on this side, stop the iteration, D x_n is the maximum halo width of the corresponding display screen, (x n , y0) is the pixel coordinates of the upper left corner corresponding to the display white box, where x n and y0 are x0 + n·Δx and y0 respectively; at this time, it is regarded as finding the maximum width halo on one side in the horizontal X direction;

[0028] (3.5) After finding the maximum width halo on one side in the horizontal X direction, ensure that the horizontal position remains unchanged, that is, the pixel coordinates x n of the upper left corner point remain unchanged. Switch the display white box to move in the vertical Y direction through the key, and repeat the same measurement steps as in steps (3.2), (3.3), and (3.4) to find the maximum width halo D y_m in the horizontal Y direction. At this time, the display white box finds the maximum width halos D x_n and D y_m on one side in the horizontal and vertical directions respectively. At this time, the pixel coordinates of the upper left corner point corresponding to the display white box are (x n , y m ), where x n and y m are x0 + n·Δx and y0 + n·Δy respectively.

[0029] Preferably, step (4) specifically includes the following steps:

[0030] (4.1) Make an opaque and non-reflective mask. Use this mask to cover the light-emitting area of the backlight display white box to eliminate the influence of the glare generated by the light-emitting area of the display white box on the halo brightness value; due to the existence of a certain diffusion angle in the LED backlight emission, the size of the mask needs to completely cover the light-emitting area of the display white box and be 1 - 2 pixel points larger than the area around the light-emitting area;

[0031] (4.2) Measure the brightness values of all pixel points on the Mini-LED zone backlight display screen when displaying a white box in a dark room environment using an imaging luminance meter. Repeat the measurement at least five times, remove the maximum and minimum data, and take the average of the remaining data; export the halo brightness distribution data of the Mini-LED zone backlight display screen in a dark room environment.

[0032] Preferably, step (5) specifically includes the following steps:

[0033] (5.1) Extract the one-dimensional brightness distribution data of the halo brightness distribution data of the Mini-LED zone backlight display screen in a dark room environment horizontally and vertically respectively, and use the medfilt1 function in Matlab to perform median filtering on the extracted one-dimensional brightness distribution data to filter out stray light noise, where the filtering parameter is set to 50. The extracted halo data follows a Gaussian distribution in the horizontal and vertical directions respectively. By using the Matlab fitting toolbox to fit the filtered horizontal and vertical pixel one-dimensional data to a Gaussian distribution, the specific fitting expression is as follows:

[0034]

[0035] Furthermore, use the fitting toolbox to automatically fit the optimal parameters a1 and σ1, and the one-dimensional Gaussian distribution formulas of the halo in the horizontal and vertical pixels can be obtained; where a1 represents the peak brightness of the halo in a single direction, σ1 determines the area or size of the halo, and σ1 represents the Mini-LED backlight zone situation;

[0036] (5.2) Furthermore, combine the one-dimensional Gaussian distribution formulas of the horizontal and vertical pixels to construct the two-dimensional field distribution expression of the halo of the Mini-LED zone backlight display screen in a dark room environment:

[0037]

[0038] where Lhalo Max represents the maximum brightness value of the halo, where dy = min(|i - up|, |j - down|), dx = min(|i - left|, |j - right|), up, down, left, and right are the upper, lower, left, and right boundary coordinates of the white box respectively, where dxc is the distance from the pixel point to the center of the white box in the horizontal direction, dyc is the distance from the pixel point to the center of the white box in the vertical direction, where σ1 represents the depth distribution width of the halo, where σ2 represents the horizontal distribution width of the halo, and σ1 and σ2 determine the area or size of the halo, where Figure 11 (Left) is the halo simulation diagram reproduced by simulating the two-dimensional field distribution expression of the halo;

[0039] (5.3) According to the two-dimensional field distribution expression of the halo of the Mini-LED zoned backlight display screen deduced from the fitting, the halo of the Mini-LED zoned backlight display screen is simulated and reproduced, and the one-dimensional luminance distribution data Data_x and Data_y of the unilateral simulated halo are extracted respectively in the horizontal and vertical directions through the central symmetry point;

[0040] (5.4) From the one-dimensional luminance distribution data Data_x of the extracted unilateral simulated halo, find the pixel point Lhalo with the maximum halo luminance value Lhalo (nits); Max and the pixel point Lhalo at the edge of the halo with a luminance value of 0.001 cd / m 2 ; where the pixel point Lhalo with the maximum halo luminance 0.001 corresponds to the i-th data in the distribution data Data_x, and the pixel point Lhalo at the edge of the halo Max corresponds to the j-th data in the distribution data Data_x, then determine the number of pixels between the two points of the pixel point with the maximum halo luminance and the pixel point at the edge of the halo as W 0.001 , whose value is |j - i| (Pixels), and then convert the number of pixels to a distance as the width of the halo in the horizontal direction. The specific conversion formula is: Halo_Pixels W

[0041] W Halo_mm = W Halo_Pixels / Width Box_Pixels *Width Box_mm

[0042] where, W Halo_mm is the maximum width value of the halo to be obtained (mm), W Halo_Pixels is the maximum width of the halo photographed by the luminance meter (Pixels), Width Box_Pixels is the maximum width of the halo photographed by the luminance meter (Pixels), Width Box_mm is the maximum width of the halo on the display screen under test (mm);

[0043] (5.5) Similarly, repeat the same measurement steps in step (5.4) to obtain the width of the halo in the vertical direction. Finally, the maximum luminance of the halo of the Mini-LED zoned backlight display screen is Lhalo Max , and the maximum width is Whalo Max , whose value corresponds to the larger of the widths in the horizontal and vertical directions, and the measurement of the maximum halo situation is completed.

[0044] The present invention discloses a maximum halo measurement system for a Mini-LED zoned backlight display screen, including:

[0045] The module for building the halo measurement device in a dark environment is used for building a darkroom environment, building a measurement device, and performing related preparations before measurement;

[0046] The module for optimizing the size of the optimal display white box is used to measure the brightness of the display white box area of the Mini-LED zoned backlight display screen in a darkroom environment, and iteratively measure the brightness corresponding to different sizes of the display white box to finally obtain the size of the display white box corresponding to the maximum display white box brightness;

[0047] The module for optimizing the position of the optimal display white box is used to perform pixel-level movement on the white box of a determined size and measure the halo situation, measure the halo of white boxes at different positions on the Mini-LED zoned backlight display screen in a darkroom environment, and determine the position of the white box corresponding to the maximum halo width;

[0048] The maximum halo measurement module is used to, after determining the size and position of the display white box, perform masking processing on the display white box area and take measurements with an imaging luminance meter to obtain the halo brightness distribution in a darkroom environment;

[0049] The two-dimensional halo field distribution simulation and reproduction module is used to measure the obtained halo brightness data in a darkroom environment, simulate and reproduce the halo to obtain the two-dimensional field distribution formula of the halo, and inversely deduce the maximum halo brightness parameter and halo width parameter through the formula;

[0050] Among them, in the module for building the halo measurement device in a dark environment, a darkroom environment is first built. Since the brightness value of the halo is very small, in order to avoid the influence of stray light, the halo measurement experiment needs to be carried out in a darkroom environment, and at the same time, it is necessary to ensure that the surface brightness of the objects in the darkroom environment is less than 0.001 cd / m 2 , and except for the Mini-LED backlight display screen, the rest of the light-emitting bodies need to be blocked with non-transparent and non-reflective black cloth;

[0051] Build a halo measurement device. The halo measurement device includes a test platform with sufficient length and width, a Mini-LED zoned backlight display screen, a host for transmitting an image source to the Mini-LED zoned backlight display screen, an imaging luminance meter for measuring the zoned backlight display screen and related fixing devices, and a host for outputting halo brightness distribution data. Among them, place the Mini-LED zoned backlight display screen to be measured at one end of the test platform, fix the imaging luminance meter on the cloud platform and place it at the other end of the platform, and place it in a suitable position so that the Mini-LED zoned backlight display screen to be measured appears completely and clearly in the field of view captured by the imaging luminance meter;

[0052] Set the display state of the screen under test. For the Mini-LED zone-backlight display screen, turn on the zone-backlight setting and HDR mode, and at the same time, set the brightness and contrast parameters to Max to ensure that the Mini-LED zone-backlight display screen can reach the maximum halo state. At the same time, provide a 30-minute warm-up time for the device under test before measurement. In addition, the screen saver of the device under test should be disabled at this time so that the display is active during the 30 minutes before the test. To ensure the consistency of the test, a white screen with maximum brightness should be used to warm up the Mini-LED zone-backlight display screen under test during this 30-minute warm-up period;

[0053] Focus the imaging luminance meter on the Mini-LED zone-backlight display screen under test. Manually adjust the focus ring of the imaging luminance meter until the image of the Mini-LED zone-backlight display screen under test can be clearly presented in the image of the imaging luminance meter, then the focusing is completed;

[0054] Preferably, a Python program is written and applied in the optimal display white box size optimization module. The code has the following functions: read the resolution of the Mini-LED zone-backlight display screen under test; achieve pixel-level display control of the Mini-LED zone-backlight display screen under test; achieve button input to control the change of the white box size of the Mini-LED zone-backlight display screen;

[0055] It is known that the maximum brightness of the display white box of the Mini-LED zone-backlight display screen shows a trend of first increasing and then decreasing as the ratio of the side length of the display white box to the size of the display screen increases. This also means that there is a maximum brightness when the display white box of the screen occupies a certain proportion of the corresponding light-emitting area, and the maximum brightness of the light-emitting area also corresponds to the maximum brightness of the halo; Therefore, a method for finding the maximum brightness of the display white box of the screen is designed: Let the resolution of the Mini-LED zone-backlight display screen under test be W Max and H Max , set the initial sizes W0 and H0 of the display white box to be W Max / 100 and H Max / 100 respectively; set the growth steps ΔW and ΔH of the length and width of the white box to be W Max / 100 and H Max / 100 respectively; the initial display position of the white box is the center position of the display screen, the gray level of the white box is full gray level, and the gray level of other areas of the display screen is 0; set the initial value of the iteration number T to 0;

[0056] The imaging luminance meter measures the luminance values of all pixel points on the Mini-LED zoned backlight display screen when displaying the initial size white box in a dark room environment, processes the luminance values of all pixel points on the display screen, and extracts the luminance values of all pixel points in the white box area displayed on the display screen. There is glare and halo around the white box area displayed, and the luminance distribution of the backlight display screen when the light-emitting area of the Mini-LED zoned backlight display screen is not blocked is obtained, and the maximum luminance is denoted as L 0_Max , and at the same time, the iteration count T is incremented by one. At this time, it is regarded as the completion of the first measurement;

[0057] After the first measurement is completed, the size of the white box displayed on the display screen is changed by pressing the keyboard control program. At this time, the size of the white box is W1 and H1, where the values of W1 and H1 are W0 + ΔW and H0 + ΔH respectively; and the same measurement steps are repeated, and the maximum luminance L corresponding to the white box sizes of W1 and H1 is obtained 1_Max , and at this time, it is regarded as the completion of the second measurement; at this time, a judgment is made: if L 1_Max >L 0_Max , then continue to execute the iteration and conduct the test; if L 1_Max <L 0_Max , then stop the iteration, and L 0_Max is the maximum luminance of the corresponding display screen, and W0 and H0 are the sizes corresponding to the white box displayed

[0058] Continuously execute the iteration and judgment. When the nth measurement occurs, where L 0_Max <L 1_Max <L 2_Max <L 3_Max <……<L n_Max <L n+1_Max <L n+2_Max <……, then stop the iteration, and L n_Max is the maximum luminance of the corresponding display screen, and W n and H n are the sizes corresponding to the white box displayed, where W n and H n are W0 + n·ΔW and H0 + n·ΔH respectively.

[0059] Preferably, in the optimal white box position optimization module, based on the Python program written in the optimal white box size optimization module, the following functions are added: realizing the movement of the white box on the Mini-LED zoned backlight display screen according to the set movement step length and set direction; realizing the key input to control the setting of the movement step length and movement direction of the white box on the Mini-LED zoned backlight display screen; realizing the recording of the movement, direction, and the coordinates of the upper left pixel point of the white box on the Mini-LED zoned backlight display screen by key control

[0060] Based on the white box displayed with the same size, the halo effect depends on the position of the white box relative to the backlight zone unit (BLU). When the white box coincides with the backlight zone unit, the halo effect is the best at this time, that is, the halo is the least obvious; when the white box just lights up a certain backlight zone unit, the halo effect is the worst at this time, and it also corresponds to the maximum halo width on one side in a certain direction. Then when the white box moves on the display screen, when the white box just moves to a new zone, the backlight of this zone is lit, and at this time, the halo width on this side in this direction will increase sharply, which corresponds to the halo width in the worst case of the halo effect on this side in this direction. As the white box continues to move in this direction, the halo width is limited by the edge of the white box to the boundary of this zone and the halo width gradually decreases. Therefore, the halo effect of the display screen needs to be measured under the worst case of the halo effect. So a method for finding the maximum halo of the screen display white box is designed: Assume that the size of the backlight zone of the Mini-LED zone backlight display screen is a pixel points. Set the white box to move first in the horizontal X direction. Assume that the initial position of the white box is the center position of the display screen, and the coordinates (x0, y0) of its upper left pixel are (W Max / 2 - W n , H Max / 2 - H n ). Set the movement step sizes of the white box as Δx and Δy to be a / 10; the gray level of the white box is full gray level, and the gray level of other areas of the display screen is 0; set the number of iterations T x The initial value is 0;

[0061] The imaging luminance meter measures the luminance values of all pixel points on the Mini-LED zone backlight display screen when the coordinates of the upper left pixel of the white box are in the position (x0, y0) in the dark room environment. Process the luminance values of all pixel points on the display screen, extract the luminance values of the halo around the white box area on the display screen, and extract the luminance values in a single direction of the halo to obtain the single-direction luminance distribution of the halo, and calculate the pixel distance between the maximum luminance value point of the halo and the 0.001 cd / m 2 luminance value point, which is the halo width denoted as D x_0 . At the same time, the number of iterations T x is incremented by one, and this is regarded as completing the first measurement;

[0062] After completing the first measurement, control the white box on the screen to move one step in the horizontal direction by pressing the keyboard. At this time, the coordinates of the upper left pixel of the white box are (x1, y0), where the values of x1 and y0 are x0 + Δx and y0 respectively; and repeat the same measurement steps, and obtain the halo width D x_1 on this side corresponding to the upper left coordinates (x1, y0) of the white box. At this time, it is regarded as completing the second measurement; at this time, a judgment is made: if D x_1 <Dx_0 , continue to perform iteration and testing; if D x_1 > D x_0 and there is a sharp increase in the halo width on this side, stop the iteration, D x_1 is the maximum halo width of the corresponding display screen, and (x1, y0) is the pixel coordinate of the upper left corner corresponding to the display white box;

[0063] Keep performing iteration and judgment. When the nth measurement occurs, where D x_0 > D x_1 > D x_2 > D x_3 > …… > D x_n-1 < D x_n > D x_n+1 > D x_n+2 > ……, at the nth measurement, there is a sharp increase in the halo width on this side, stop the iteration, D x_n is the maximum halo width of the corresponding display screen, (x n , y0) is the pixel coordinate of the upper left corner corresponding to the display white box, where x n and y0 are x0 + n·Δx and y0 respectively; at this time, it is regarded as finding the maximum width halo on one side in the horizontal X direction;

[0064] After finding the maximum width halo on one side in the horizontal X direction, ensure that the horizontal position remains unchanged, that is, the pixel point coordinate x n remains unchanged. Switch the display white box to move in the vertical Y direction through the key, and repeat the same measurement steps to find the maximum width halo D y_m in the horizontal Y direction. At this time, the display white box finds the maximum width halos D x_n and D y_m on one side in the horizontal and vertical directions respectively. At this time, the pixel coordinate of the upper left corner corresponding to the display white box is (x n , y m ), where x n and y m are x0 + n·Δx and y0 + n·Δy respectively.

[0065] Preferably, in the maximum halo measurement module, make an opaque and non-reflective mask, use this mask to block the light-emitting area of the backlight display white box, and eliminate the influence of the glare generated by the light-emitting area of the display white box on the halo brightness value; due to the existence of a certain diffusion angle in the LED backlight emission, the size of the mask needs to completely cover the light-emitting area of the display white box and be 1 - 2 pixel points larger than the surrounding of the light-emitting area;

[0066] Measure the brightness values of all pixel points on the Mini-LED zone-backlight display screen when showing a white box in a dark room environment using an imaging luminance meter. Repeat the measurement at least five times, remove the maximum and minimum data, and take the average of the remaining data; export the halo brightness distribution data of the Mini-LED zone-backlight display screen in the dark room environment.

[0067] Preferably, in the two-dimensional halo field distribution simulation and reproduction module, extract the one-dimensional brightness distribution data in the horizontal and vertical directions respectively from the exported halo brightness distribution data of the Mini-LED zone-backlight display screen in the dark room environment, and apply the medfilt1 function in Matlab to perform median filtering on the extracted one-dimensional brightness distribution data to filter out stray light noise, where the filtering parameter is set to 50. The extracted halo data follows a Gaussian distribution in the horizontal and vertical directions respectively. By using the Matlab fitting toolbox to fit the filtered one-dimensional data of horizontal and vertical pixels to a Gaussian distribution, the one-dimensional Gaussian distribution formulas of the halo in the horizontal and vertical pixels can be obtained;

[0068] Furthermore, combine the one-dimensional Gaussian distribution formulas of the horizontal and vertical pixels to construct an expression for the two-dimensional field distribution of the halo of the Mini-LED zone-backlight display screen in the dark room environment:

[0069] According to the expression for the two-dimensional field distribution of the halo of the Mini-LED zone-backlight display screen derived from the fitting, simulate and reproduce the halo of the Mini-LED zone-backlight display screen, and extract the one-dimensional brightness distribution data Data_x and Data_y of the unilateral simulated halo in the horizontal and vertical directions respectively through the central symmetry point;

[0070] From the extracted one-dimensional brightness distribution data Data_x of the unilateral simulated halo, find the pixel point Lhalo with the maximum halo brightness value Lhalo(nits) Max and the pixel point Lhalo at the edge of the halo with a brightness value of 0.001 cd / m 2 , where the pixel point Lhalo of the maximum halo brightness 0.001 corresponds to the i-th data in the distribution data Data_x, and the pixel point Lhalo at the edge of the halo Max corresponds to the j-th data in the distribution data Data_x, then determine the number of pixels between the two points of the pixel point of the maximum halo brightness and the pixel point at the edge of the halo as W 0.001 , whose value is |j - i| (Pixels), and then convert the number of pixels to a distance as the width of the halo in the horizontal direction; Halo_Pixels

[0071] ​Similarly, repeat the same measurement steps to get the width of the halo in the vertical direction. Finally, the maximum brightness of the halo of the Mini-LED partition backlight display screen is Lhalo Max , the maximum width is Whalo Max , its value corresponds to the larger of the horizontal and vertical widths, at which point the measurement of the maximum halo of the Mini-LED partition backlight display screen is completed.

[0072] Beneficial effects: Compared with the existing technology, the present invention has the following significant advantages: First, the present invention builds a halo measurement device in a dark environment, and then uses the optimal display white box size optimization method to find the display white box size corresponding to when the display white box obtains maximum brightness, and then uses the optimal display white box position optimization module to find the display white box position corresponding to when the display white box obtains maximum halo width, and then measures the maximum halo effect found in a dark environment, and finally simulates and reproduces the two-dimensional halo field distribution to obtain the maximum halo brightness and maximum halo width corresponding to the halo effect. After adopting the method of the present invention, the maximum halo situation can be found and measured for any Mini-LED display screen, and the static halo can be quantitatively analyzed, thereby effectively improving the precision and accuracy of the halo effect test of the Mini-LED display screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 Schematic diagram of the structure of the halo measurement device in the present invention;

[0074] Figure 2 Schematic diagram of the overall flow of the measurement steps in the present invention;

[0075] Figure 3 Schematic diagram of the process of the method for finding the optimal display white box size in the present invention;

[0076] Figure 4 Schematic diagram of the method for finding the white box size of the maximum brightness of the halo in the present invention;

[0077] Figure 5 Schematic diagram of the process of the method for finding the optimal display white box position in the present invention;

[0078] Figure 6 Schematic diagram of the method for finding the position of the white box with the maximum halo width in the X direction in the present invention;

[0079] Figure 7 This is a photo of the halo of the present invention;

[0080] Figure 8 Processing three-dimensional images of the photographed data of the present invention;

[0081] Figure 9 Four horizontal pixel data distribution diagrams taken for the present invention;

[0082] Figure 10 Vertical pixel data distribution diagram obtained for the present invention;

[0083] Figure 11 Two-dimensional distribution formula simulation diagram (a) and simulation pseudo-color diagram (b) in the present invention;

[0084] Figure 12 One-dimensional luminance distribution data obtained by simulating halos in the horizontal and vertical directions in the present invention. Detailed implementation manners

[0085] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0086] Embodiment 1

[0087] A method for measuring the maximum halo of a Mini-LED zoned backlight display screen in the present invention. The overall process of the measurement steps is as Figure 2 shown, and specifically includes the following steps:

[0088] (1) Set up a halo measurement device in a dark environment;

[0089] Among them, step (1) specifically includes the following steps:

[0090] (1.1) Set up a darkroom environment. Since the luminance value of the halo is very small, in order to avoid the influence of stray light, the halo measurement experiment needs to be carried out in a darkroom environment, and at the same time, it is necessary to ensure that the surface luminance of the objects in the darkroom environment is less than 0.001 cd / m 2 , and all light-emitting bodies except the Mini-LED backlight display screen need to be covered with non-transparent and non-reflective black cloth;

[0091] (1.2) Set up a halo measurement device, as Figure 1As shown in the figure, the halo measurement device specifically includes a test operation table 101, an imaging luminance meter 201 for measuring the imaging luminance of a zoned backlight display screen, a host A 202 for outputting halo luminance distribution data, a pan-tilt head 203, a measured Mini-LED zoned backlight display screen 301, and a host B 302 for transmitting an image source to the Mini-LED zoned backlight display screen; the test operation table 101 is placed in a dark environment laboratory for placing relevant test equipment, and the operation table needs to ensure a length greater than 3 meters to meet the distance requirements for shooting; the measured screen 301 and the host B 302 are placed at one end of the test platform. The host B 302 can support the output of a high-dynamic range HDR video source. The host A 202 and the imaging luminance meter 201 are fixed on the pan-tilt head 203 and placed at the other end of the platform. They are placed in a suitable position so that the measured Mini-LED zoned backlight display screen appears completely and clearly in the field of view captured by the imaging luminance meter. The host A 202 is used to control the surface luminance meter to take pictures and record the captured data. To ensure the darkroom environment, the host A 202 should be covered with an opaque and non-reflective black cloth during shooting;

[0092] (1.3) Assurance of the display state of the measured screen. The Mini-LED zoned backlight display screen should turn on the zoned backlight setting and HDR mode, and at the same time, the brightness and contrast parameters should be set to Max to ensure that the Mini-LED zoned backlight display screen can reach the maximum halo state. At the same time, the measured device needs to be preheated for 30 minutes before measurement. In addition, the screen saver of the measured device should be disabled at this time so that the display is active during the 30 minutes before the test. To ensure the consistency of the test, a white screen with the maximum brightness should be used to preheat the measured Mini-LED zoned backlight display screen during this 30-minute preheating period;

[0093] (1.4) Assurance of the performance of the test equipment. The resolution of the imaging luminance meter used in the test needs to be greater than the resolution of the measured display area, so that the brightness of each pixel can be accurately measured. The resolution of the imaging luminance meter is greater than the resolution of the measured display screen, so that the brightness of each pixel point of the measured display screen can be accurately measured. If the resolution of the imaging luminance meter is less than the resolution of the measured display screen, the brightness difference between different pixel points cannot be measured;

[0094] (1.5) Perform focusing processing on the imaging luminance meter and the measured Mini-LED zoned backlight display screen. Manually adjust the focusing ring of the imaging luminance meter until the image of the measured Mini-LED zoned backlight display screen can be clearly presented in the image of the imaging luminance meter, then the focusing is completed.

[0095] (2) Measure the brightness of the white box area of the Mini-LED zoned backlight display screen in a dark room environment, and iteratively measure the brightness corresponding to different sizes of the white box to finally obtain the size of the white box corresponding to the maximum brightness of the white box during display.

[0096] The optimization method process for the optimal white box size is as Figure 3 shown, and specifically includes the following steps:

[0097] (2.1) Apply the written Python program, and the code has the following functions:

[0098] (2.1.1) Read the resolution of the measured Mini-LED zoned backlight display screen;

[0099] (2.1.2) Implement pixel-level display control of the measured Mini-LED zoned backlight display screen;

[0100] (2.1.3) Implement key input to control the change of the white box size of the Mini-LED zoned backlight display screen;

[0101] (2.2) It is known that the maximum brightness of the white box of the Mini-LED zoned backlight display screen shows a trend as Figure 4 . As the ratio of the side length of the white box to the size of the display screen increases, the maximum brightness value of the white box first increases and then decreases. For example, in Figure 4 , the ratio of the side length of the white box in Box1 to the size of the display screen is 0.2, and at this time, the maximum brightness of the white box only reaches 50% of the maximum brightness that the display screen can achieve; as the ratio of the side length of the white box to the size of the display screen increases, when the ratio of the side length of the white box to the size of the display screen reaches approximately 0.35, that is, at the position of Box2, the maximum brightness of the white box can reach the maximum brightness that the display screen can achieve; but as the ratio of the side length of the white box to the size of the display screen continues to increase, the maximum brightness of the white box slowly decreases, such as Box3. This also means that there is a maximum brightness for the white box at a certain corresponding size, and the maximum brightness of the light-emitting area also corresponds to the maximum brightness of the halo;

[0102] Therefore, design a method for finding the maximum brightness of the white box on the screen: Let the resolution of the measured Mini-LED zoned backlight display screen be W Max and H Max , and set the initial sizes W0 and H0 of the white box to be W Max / 100 and H Max / 100 respectively; set the growth step sizes ΔW and ΔH of the length and width of the white box to be W Max / 100 and H Max / 100; The initial display position of the white box is the center position of the display screen. The gray level of the white box is full gray level, and the gray level of other areas of the display screen is 0; Set the initial value of the iteration count T to 0;

[0103] (2.3) The imaging luminance meter measures the luminance values of all pixel points on the display screen when the white box of the initial size of the Mini-LED zoned backlight display screen is shown in the darkroom environment. Process the luminance values of all pixel points on the display screen, and extract the luminance values of all pixel points in the area where the white box is shown on the display screen. There is glare and halo around the area where the white box is shown, and obtain the luminance distribution of the backlight display screen when the light-emitting area of the Mini-LED zoned backlight display screen is not blocked, and record the maximum luminance as L 0_Max , and at the same time, increment the iteration count T by one. At this time, it is regarded as completing the first measurement;

[0104] (2.4) After completing the first measurement, change the size of the white box shown on the display screen by pressing the keyboard control program. At this time, the size of the white box is W1 and H1, where the values of W1 and H1 are W0 + ΔW and H0 + ΔH respectively; and repeat the same measurement steps as in step (2.3), and obtain the maximum luminance L corresponding to the white box sizes of W1 and H1 1_Max , and at this time, it is regarded as completing the second measurement; At this time, make a judgment: If L 1_Max > L 0_Max , then continue to execute the iteration and conduct the test; If L 1_Max < L 0_Max , then stop the iteration, and L 0_Max is the maximum luminance of the corresponding display screen, and W0 and H0 are the sizes corresponding to the white box shown;

[0105] (2.5) Continuously execute the iteration and judgment. When the nth measurement occurs, where L 0_Max < L 1_Max < L 2_Max < L 3_Max <... < L n_Max < L n+1_Max < L n+2_Max <... < L n_Max is the maximum luminance of the corresponding display screen, and W n and H n are the sizes corresponding to the white box shown, where W n and H n are W0 + n·ΔW and H0 + n·ΔH respectively.

[0106] (3) After determining the size of the white box shown, measure the halo situation by performing pixel-level movement on the white box of the determined size, measure the halo of the white box at different positions on the Mini-LED zoned backlight display screen in the darkroom environment, and determine the position of the white box corresponding to the maximum halo width;

[0107] The optimization method for the optimal display white box position is as follows Figure 5 shown, specifically including the following steps:

[0108] (3.1) Based on the Python program written in step (2), add code to make it have the following functions:

[0109] (3.1.1) Implement the movement of the white box on the Mini-LED zone-backlight display screen according to the set movement step size and direction;

[0110] (3.1.2) Implement key input to control the setting of the movement step size and direction of the white box on the Mini-LED zone-backlight display screen;

[0111] (3.1.3) Implement key control to record the movement, direction, and the coordinates of the top-left pixel point of the white box on the Mini-LED zone-backlight display screen;

[0112] (3.2) On the basis of the display white box with the same size, the halo effect is as follows Figure 6 shown and depends on the position of the display white box relative to the backlight zone unit (BLU). When the position of the display white box such as Figure 6 Box1 in coincides with the backlight zone unit, the halo effect is the best at this time, that is, the halo is the least obvious; when the display white box is at the position of Box3 in Figure 6 and just lights up a certain backlight zone unit, the halo effect is the worst at this time, and it also corresponds to the maximum halo width on one side in a certain direction. Then when the display white box moves on the display screen, when the display white box just moves to a new zone, the backlight of this zone is lit, and at this time, the halo width on this side in this direction will increase sharply, and at this time, it corresponds to the halo width in the worst case of the halo effect on this side in this direction. As the display white box continues to move in this direction, the halo width is limited by the edge of the display white box to the boundary of this zone and the halo width gradually decreases. Therefore, the halo effect of the display screen needs to be measured under the worst case of the halo effect.

[0113] Therefore, design a method for finding the maximum halo of the screen display white box: Assume that the size of the backlight zone of the Mini-LED zone-backlight display screen is a pixel points, set the display white box to move first in the horizontal X direction, set the initial position of the display white box to the center position of the display screen, and the coordinates (x0, y0) of its top-left pixel are (W Max / 2 - W n , H Max / 2 - H n ), set the movement step sizes of the white box Δx and Δy to a / 10; the gray level of the white box is full gray level, and the gray level of other areas of the display screen is 0; set the number of iterations T xThe initial value is 0;

[0114] (3.3) The imaging luminance meter measures the luminance values of all pixel points on the Mini-LED zoned backlight display screen in a dark room environment when the pixel position coordinates of the upper left corner of the white box displayed are (x0, y0). Process the luminance values of all pixel points on the display screen, extract the luminance values of the halo around the white box area on the display screen, and extract the luminance values in a single direction of the halo to obtain the luminance distribution in a single direction of the halo, and calculate the pixel distance between the point with the maximum halo luminance value and the 0.001 cd / m 2 The luminance value point is the halo width, denoted as D x_0 , and at the same time, the iteration count T x is incremented by one, and at this time, it is regarded as completing the first measurement;

[0115] (3.4) After completing the first measurement, press the keyboard to control the white box displayed on the screen to move one step in the horizontal direction. At this time, the pixel coordinates of the upper left corner of the white box are (x1, y0), where the values of x1 and y0 are x0 + Δx and y0 respectively; and repeat the same measurement steps as in step (3.3), and obtain the corresponding halo width D on this side when the upper left corner coordinates of the white box are (x1, y0) x_1 , and at this time, it is regarded as completing the second measurement; at this time, make a judgment: if D x_1 <D x_0 , then continue to execute the iteration and conduct the test; if D x_1 >D x_0 and there is a steep increase in the halo width on this side, then stop the iteration, and D x_1 is the maximum halo width of the corresponding display screen, and (x1, y0) is the pixel coordinates of the upper left corner corresponding to the white box;

[0116] (3.5) Continuously execute the iteration and judgment. When the nth measurement occurs, where D x_0 >D x_1 >D x_2 >D x_3 >……>D x_n-1 <D x_n >D x_n+1 >D x_n+2 >……, at the nth measurement, if there is a steep increase in the halo width on this side, then stop the iteration, and D x_n is the maximum halo width of the corresponding display screen, and (x n , y0) is the pixel coordinates of the upper left corner corresponding to the white box, where x n and y0 are x0 + n·Δx and y0 respectively; at this time, it is regarded as finding the maximum-width halo on the single side in the horizontal X direction, that is, as in Figure 6 the position of Box3;

[0117] (3.6) After finding the maximum-width halo on one side in the horizontal X direction, ensure that the horizontal position remains unchanged, that is, the x coordinate of the upper-left pixel point n remains unchanged. By pressing the button, switch to display the white box moving in the vertical Y direction, and repeat the same measurement steps as in step (3.3), step (3.4), and step (3.5) to find the maximum-width halo D on one side in the horizontal Y direction y_m , that is, such as Figure 6 the position of Box3; at this time, display that the white box finds the maximum-width halos D x_n and D y_m on one side in the horizontal and vertical directions respectively. At this time, the coordinates of the upper-left pixel point corresponding to the displayed white box are (x n , y m ), where x n and y m are x0 + n·Δx and y0 + n·Δy respectively.

[0118] (4) After determining the size and position of the displayed white box, perform masking on the displayed white box area and use an imaging luminance meter to take pictures and measure to obtain the halo luminance distribution in the darkroom environment;

[0119] Among them, step (4) specifically includes the following steps:

[0120] (4.1) Make an opaque and non-reflective mask, use this mask to cover the light-emitting area of the backlight display showing the white box, and eliminate the influence of the glare generated by the light-emitting area of the displayed white box on the halo luminance value; due to the existence of a certain diffusion angle in the LED backlight emission, the size of the mask needs to completely cover the light-emitting area of the displayed white box and be 1-2 pixel points larger than the surrounding of the light-emitting area;

[0121] (4.2) Use an imaging luminance meter to measure the luminance values of all pixel points on the Mini-LED partition backlight display screen when showing the white box in the darkroom environment, repeat the measurement at least five times, remove the maximum and minimum data, and take the average of the remaining data; the specific halo shooting effect is as Figure 7 shown, export the halo luminance distribution data of the Mini-LED partition backlight display screen in the darkroom environment, and the pseudo-color map of the halo distribution is as Figure 8 shown.

[0122] (5) According to the obtained halo luminance data in the darkroom environment, simulate and reproduce the halo to obtain the two-dimensional field distribution formula of the halo, and inversely deduce the maximum luminance parameter and the halo width parameter of the halo through the formula.

[0123] Among them, step (5) specifically includes the following steps:

[0124] (5.1) Arrange the exported halo luminance distribution data of the Mini-LED partition backlight display screen in the darkroom environment asFigure 8 The one-dimensional luminance distribution data is extracted horizontally and vertically by dashed lines. The one-dimensional luminance distribution data with different Y values extracted horizontally is as Figure 9 shown, and the one-dimensional luminance distribution data extracted vertically is as Figure 10 shown; after the extraction is completed, the medfilt1 function in Matlab is used to perform median filtering on the extracted one-dimensional luminance distribution data to filter out stray light noise, and the filtering parameter is set to 50. It can be found from the picture that the extracted halo data follows a Gaussian distribution in both the horizontal and vertical directions. By using the Matlab fitting toolbox to fit the filtered one-dimensional data of horizontal and vertical pixels to a Gaussian distribution, the fitting curve of the one-dimensional vertical distribution data is as Figure 10 shown by the solid line in, and the specific fitting expression is as follows:

[0125]

[0126] Furthermore, by using the fitting toolbox to automatically fit the optimal parameters a1 and σ1, the one-dimensional Gaussian distribution formulas of the halo in the horizontal and vertical pixels can be obtained; where a1 represents the peak luminance of the halo in a single direction, σ1 determines the area or size of the halo, and σ1 represents the Mini-LED backlight partition situation;

[0127] (5.2) Furthermore, by combining the one-dimensional Gaussian distribution formulas of the horizontal and vertical pixels, the two-dimensional field distribution expression of the halo of the Mini-LED partition backlight display screen in a dark room environment is constructed:

[0128]

[0129] where Lhalo Max represents the maximum luminance value of the halo, where dy = min(|i - up|, |j - down|), dx = min(|i - left|, |j - right|), up, down, left, and right are the upper, lower, left, and right boundary coordinates of the white box, where dxc is the distance from the pixel point to the center of the white box in the horizontal direction, dyc is the distance from the pixel point to the center of the white box in the vertical direction, where σ1 represents the depth distribution width of the halo, where σ2 represents the horizontal distribution width of the halo, and σ1 and σ2 determine the area or size of the halo, where Figure 11 (left) is the halo simulation diagram reproduced by simulating the two-dimensional field distribution expression of the halo;

[0130] (5.3) According to the two-dimensional field distribution expression of the halo of the Mini-LED partition backlight display screen derived from the fitting, the halo of the Mini-LED partition backlight display screen is simulated and reproduced as Figure 11As shown in the figure on the right (right), extract the one-dimensional luminance distribution data Data_x and Data_y of the unilateral simulated halo in the horizontal and vertical directions respectively through the central symmetry point. The specific one-dimensional data distribution is as follows Figure 12 shown, where the left figure is the Data_x data graph extracted in the horizontal direction, and the right figure is the Data_y data graph extracted in the vertical direction;

[0131] (5.4) In Figure 12 the one-dimensional luminance distribution data Data_x of the unilateral simulated halo in the left figure, find the pixel point Lhalo with the maximum halo luminance value Lhalo (nits) Max and the pixel point Lhalo at the edge of the halo with a luminance value of 0.001 cd / m 2 where the pixel point Lhalo with the maximum halo luminance 0.001 corresponds to the i-th data in the distribution data Data_x, and the pixel point Lhalo at the edge of the halo Max corresponds to the j-th data in the distribution data Data_x. Then, determine that the number of pixels between the pixel point with the maximum halo luminance and the pixel point at the edge of the halo is W 0.001 , whose value is |j - i| (Pixels). Then, convert the number of pixels to a distance as the width of the halo in the horizontal direction. The specific conversion formula is: Halo_Pixels

[0132] W Halo_mm = W Halo_Pixels / Width Box_Pixels *Width Box_mm

[0133] where W Halo_mm is the maximum width value of the halo to be obtained (mm), W Halo_Pixels is the maximum width of the halo captured by the luminance meter (Pixels), Width Box_Pixels is the maximum width of the halo captured by the luminance meter (Pixels), Width Bo _mm x is the maximum width of the halo on the display screen under test (mm);

[0134] (5.5) Similarly, repeat the same measurement steps as in step (5.4) to obtain the width of the halo in the vertical direction. Finally, the maximum luminance of the halo of the Mini-LED zoned backlight display screen is Lhalo (5.5) Similarly, repeat the same measurement steps as in step (5.4) to obtain the width of the halo in the vertical direction. Finally, the maximum luminance of the halo of the Mini-LED zoned backlight display screen is Lhalo Max , and the maximum width is Whalo Max , and the value of Whalo Max corresponds to the larger value of the halo widths in the horizontal and vertical directions, completing the measurement of the halo.

[0135] Example 2

[0136] The present invention discloses a maximum halo measurement system for a Mini-LED zoned backlight display screen, comprising:

[0137] A halo measurement device building module in a dark environment, which is used for building a darkroom environment, building a measurement device, and performing related pre-measurement preparations;

[0138] Among them, in the halo measurement device building module in a dark environment, a darkroom environment is first built. Since the brightness value of the halo is very small, in order to avoid the influence of stray light, the halo measurement experiment needs to be carried out in a darkroom environment, and at the same time, it is necessary to ensure that the surface brightness of the objects in the darkroom environment is less than 0.001 cd / m 2 , and except for the Mini-LED backlight display screen, the rest of the light-emitting bodies need to be blocked with non-transparent and non-reflective black cloth;

[0139] Build a halo measurement device, as Figure 1 shown. The halo measurement device specifically includes a test operation table 101, an imaging luminance meter 201 for measuring the zoned backlight display screen, a host A 202 for outputting halo brightness distribution data, a pan-tilt 203, a measured Mini-LED zoned backlight display screen 301, and a host B 302 for transmitting an image source to the Mini-LED zoned backlight display screen; the test operation table 101 is placed in a dark environment laboratory for placing relevant test equipment, and the operation table needs to ensure a length greater than 3 meters to meet the shooting distance requirements; the measured screen 301 and the host B 302 are placed at one end of the test platform. The host B 302 can support the output of a high-dynamic range HDR video source. The host A 202 and the imaging luminance meter 201 are fixed on the pan-tilt 203 and placed at the other end of the platform, and placed in a suitable position so that the measured Mini-LED zoned backlight display screen appears completely and clearly in the field of view captured by the imaging luminance meter. The host A 202 is used to control the surface luminance meter to take pictures and record the captured data. To ensure the darkroom environment, the host A 202 should be blocked with non-transparent and non-reflective black cloth during shooting;

[0140] Set the display state of the measured screen. The Mini-LED zoned backlight display screen needs to turn on the zoned backlight setting and HDR mode, and at the same time, the brightness and contrast parameters need to be set to Max to ensure that the Mini-LED zoned backlight display screen can reach the maximum halo state. At the same time, before measuring the device to be measured, the device to be measured needs to be preheated for 30 minutes, and a white screen with the maximum brightness is used to preheat the measured Mini-LED zoned backlight display screen during the preheating period;

[0141] The imaging luminance meter is focused on the Mini-LED zoned backlight display screen to be measured. By manually adjusting the focus ring of the imaging luminance meter until the image of the Mini-LED zoned backlight display screen to be measured can be clearly presented in the image of the imaging luminance meter, the focusing is completed;

[0142] Preferably, a Python program is written and applied in the optimal display white box size optimization module. The code has the following functions: reading the resolution of the Mini-LED zoned backlight display screen to be measured; realizing pixel-level display control of the Mini-LED zoned backlight display screen to be measured; realizing button input to control the change of the white box size of the Mini-LED zoned backlight display screen;

[0143] The maximum brightness of the display white box of the known Mini-LED zoned backlight display screen is presented as Figure 4 the trend that as the ratio of the side length of the display white box to the size of the display screen increases, the maximum brightness value of the display white box first increases and then decreases, as shown in Figure 4 in which the ratio of the side length of the Box1 display white box to the size of the display screen is 0.2, and at this time the maximum brightness of the display white box only reaches 50% of the maximum brightness that the display screen can reach; as the ratio of the side length of the display white box to the size of the display screen increases, when the ratio of the side length of the display white box to the size of the display screen reaches about 0.35, that is, at the Box2 position, at this time the maximum brightness of the display white box can reach the maximum brightness that the display screen can reach; but as the ratio of the side length of the display white box to the size of the display screen continues to increase, the maximum brightness of the display white box slowly decreases, such as Box3. This also means that there is a maximum brightness for the display white box under a certain corresponding size, and the maximum brightness of the light-emitting area also corresponds to the maximum brightness of the halo;

[0144] Therefore, a method for finding the maximum brightness of the screen display white box is designed: Let the resolution of the Mini-LED zoned backlight display screen to be measured be W Max and H Max , set the initial sizes W0 and H0 of the display white box to be W Max / 100 and H Max / 100 respectively; set the growth step sizes ΔW and ΔH of the length and width of the white box to be W Max / 100 and H Max / 100 respectively; the initial display position of the white box is the center position of the display screen, the gray level of the white box is full gray level, and the gray level of other areas of the display screen is 0; set the initial value of the iteration number T to 0;

[0145] The imaging luminance meter measures the luminance values of all pixel points on the Mini-LED zoned backlight display screen when displaying a white box with the initial size in a dark room environment, processes the luminance values of all pixel points on the display screen, and extracts the luminance values of all pixel points in the white box area displayed on the display screen. There is glare and halo around the white box area displayed, and the luminance distribution of the backlight display screen when the light-emitting area of the Mini-LED zoned backlight display screen is not blocked is obtained, and the maximum luminance is denoted as L 0_Max , and at the same time, the iteration count T is incremented by one. At this time, it is regarded as completing the first measurement;

[0146] After completing the first measurement, the size of the white box displayed on the display screen is changed by pressing the keyboard control program. At this time, the size of the white box is W1 and H1, where the values of W1 and H1 are W0 + ΔW and H0 + ΔH respectively; and the same measurement steps are repeated, and the maximum luminance L corresponding to the white box sizes of W1 and H1 is obtained 1_Max , and at this time, it is regarded as completing the second measurement; at this time, a judgment is made: if L 1_Max > L 0_Max , then continue to execute the iteration and conduct the test; if L 1_Max < L 0_Max , then stop the iteration, and L 0_Max is the maximum luminance of the corresponding display screen, and W0 and H0 are the sizes corresponding to the white box

[0147] Keep executing the iteration and judgment. When the nth measurement occurs, where L 0_Max < L 1_Max < L 2_Max < L 3_Max <...... < L n_Max < L n+1_Max < L n+2_Max <......, then stop the iteration, and L n_Max is the maximum luminance of the corresponding display screen, and W n and H n are the sizes corresponding to the white box, where, W n and H n are W0 + n·ΔW and H0 + n·ΔH respectively

[0148] Preferably, in the optimal white box position optimization module, based on the Python program written in the optimal white box size optimization module, the following functions are added: realizing the movement of the white box on the Mini-LED zoned backlight display screen according to the set movement step length and set direction; realizing the key input to control the setting of the movement step length and movement direction of the white box on the Mini-LED zoned backlight display screen; realizing the recording of the movement, direction, and the coordinates of the upper left pixel point of the white box on the Mini-LED zoned backlight display screen by key control

[0149] Based on the white box being displayed in the same size, the halo effect is as Figure 6 shown and depends on the position of the display white box relative to the backlight partition unit (BLU). When the position of the display white box such as Figure 6 Box1 in coincides with the backlight partition unit, the halo effect is the best at this time, that is, the halo is the least obvious; when the position of the display white box such as Figure 6 Box3 in just lights up a certain backlight partition unit, the halo effect is the worst at this time, and it also corresponds to the maximum halo width on one side in a certain direction. Then when the display white box moves on the display screen, when the display white box just moves to a new partition and the backlight of this partition is lit, the halo width on this side in this direction will suddenly increase. At this time, it corresponds to the halo width in the worst case of the halo effect on this side in this direction. As the display white box continues to move in this direction, the halo width is limited by the edge of the display white box to the boundary of this partition and the halo width gradually decreases. Therefore, the halo effect of the display screen needs to be measured under the worst case of the halo effect.

[0150] Therefore, a method for finding the maximum halo of the screen display white box is designed: assume that the size of the backlight partition of the Mini-LED partition backlight display screen is a pixel points, and it is set that the display white box first moves in the horizontal X direction. Assume that the initial position of the display white box is the center position of the display screen, and the coordinates (x0, y0) of its upper left corner pixel are (W Max / 2 - W n , H Max / 2 - H n ). Set the movement step sizes of the white box as Δx and Δy to be a / 10; the gray level of the white box is full gray level, and the gray level of other areas of the display screen is 0; set the initial value of the iteration number T x to be 0;

[0151] The imaging luminance meter measures the luminance values of all pixel points on the Mini-LED partition backlight display screen when the coordinates of the upper left corner pixel of the display white box are in (x0, y0) in a dark room environment, processes the luminance values of all pixel points on the display screen, extracts the luminance values of the halo around the area of the display white box on the display screen, extracts the luminance values in a single direction of the halo, obtains the single-direction luminance distribution of the halo, and calculates that the pixel distance between the maximum luminance value point of the halo and the 0.001 cd / m 2 luminance value point is the halo width denoted as D x_0 , and at the same time, the iteration number T x is incremented by one, and this is regarded as completing the first measurement;

[0152] After the first measurement is completed, press the keyboard to control the white box on the screen to move one step horizontally. At this time, the pixel coordinates of the upper left corner of the white box are (x1, y0), where the values of x1 and y0 are x0 + Δx and y0 respectively; and repeat the same measurement steps, and obtain the width D of the halo on this side corresponding to the upper left corner coordinates of the white box at (x1, y0). x_1 , which is regarded as the completion of the second measurement at this time; make a judgment at this time: if D x_1 < D x_0 , then continue to execute the iteration and conduct the test; if D x_1 > D x_0 and there is a steep increase in the width of the halo on this side, then stop the iteration, D x_1 is the maximum halo width of the corresponding display screen, and (x1, y0) is the pixel coordinates of the upper left corner corresponding to the display white box;

[0153] Continuously execute the iteration and judgment. When the nth measurement occurs, where D x_0 > D x_1 > D x_2 > D x_3 >... > D x_n-1 < D x_n > D x_n+1 > D x_n+2 >...,. At the nth measurement, if there is a steep increase in the width of the halo on this side, then stop the iteration, D x_n is the maximum halo width of the corresponding display screen, (x n , y0) is the pixel coordinates of the upper left corner corresponding to the display white box, where x n and y0 are x0 + n·Δx and y0 respectively; at this time, it is regarded as finding the maximum-width halo on one side in the horizontal X direction, that is, the position of Box3 in Figure 6 ;

[0154] After finding the maximum-width halo on one side in the horizontal X direction, ensure that the horizontal position remains unchanged, that is, the pixel point coordinate x n remains unchanged. Press the key to switch the display white box to move in the vertical Y direction, and repeat the above same measurement steps to find the maximum-width halo D y_m on one side in the horizontal Y direction, that is, the position of Box3 in Figure 6 ; at this time, the display white box finds the maximum-width halos D x_n and D y_m on one side in the horizontal and vertical directions respectively. At this time, the pixel coordinates of the upper left corner corresponding to the display white box are (x n , y m ), where x n and y m are x0 + n·Δx and y0 + n·Δy respectively.

[0155] Preferably, in the maximum halo measurement module, an opaque and non-reflective mask is fabricated. The mask is used to block the light-emitting area of the white box displayed on the backlight display, eliminating the influence of the glare generated by the light-emitting area of the white box on the halo brightness value. Since there is a certain diffusion angle in the LED backlight emission, the size of the mask needs to completely cover the light-emitting area of the white box and be 1-2 pixel points larger than the area around the light-emitting area.

[0156] Use an imaging luminance meter to measure the brightness values of all pixel points on the Mini-LED zoned backlight display screen when displaying the white box in a dark room environment. Measure at least five times, remove the maximum and minimum data, and take the average of the remaining data. Export the halo brightness distribution data of the Mini-LED zoned backlight display screen in a dark room environment.

[0157] Preferably, in the two-dimensional halo field distribution simulation and reproduction module, the exported halo brightness distribution data of the Mini-LED zoned backlight display screen in a dark room environment is extracted into one-dimensional brightness distribution data horizontally and vertically as shown by the dotted lines. Among them, the one-dimensional brightness distribution data of different Y values extracted horizontally is as shown in Figure 8 and the one-dimensional brightness distribution data extracted vertically is as shown in Figure 9 . After extraction, use the medfilt1 function in Matlab to perform median filtering on the extracted one-dimensional brightness distribution data to filter out stray light noise, where the filtering parameter is set to 50. It can be found from the picture that the extracted halo data follows a Gaussian distribution in both the horizontal and vertical directions. By using the Matlab fitting toolbox to fit the filtered horizontal and vertical pixel one-dimensional data to a Gaussian distribution, the fitting curve of the vertical one-dimensional distribution data is as shown by the solid line in Figure 10 , and the one-dimensional Gaussian distribution formulas of the halo in the horizontal and vertical pixels are obtained by fitting; Figure 10

[0158] Furthermore, combine the one-dimensional Gaussian distribution formulas of the horizontal and vertical pixels to construct an expression for the two-dimensional halo field distribution of the Mini-LED zoned backlight display screen in a dark room environment, where Figure 11 (left) is the halo simulation diagram reproduced by using the two-dimensional halo field distribution expression;

[0159] According to the expression for the two-dimensional halo field distribution of the Mini-LED zoned backlight display screen in a dark room environment derived by fitting, simulate and reproduce the halo of the Mini-LED zoned backlight display screen as shown in Figure 11 (right). Extract the one-dimensional brightness distribution data Data_x and Data_y of the unilateral simulated halo horizontally and vertically through the central symmetry point. The specific one-dimensional data distribution is as shown in Figure 12 , where the left figure is the Data_x data graph extracted horizontally and the right figure is the Data_y data graph extracted vertically;​

[0160] In Figure 12 the one-dimensional luminance distribution data Data_x of the unilateral simulated halo in the left figure, find the pixel point Lhalo with the maximum halo luminance value Lhalo (nits). Max and the pixel point Lhalo at the edge of the halo with a luminance value of 0.001 cd / m 2 . 0.001 Among them, the pixel point Lhalo with the maximum halo luminance Max corresponds to the i-th data in the distribution data Data_x, and the pixel point Lhalo at the edge of the halo 0.001 corresponds to the j-th data in the distribution data Data_x. Then, determine the number of pixels between the pixel point with the maximum halo luminance and the pixel point at the edge of the halo as W Halo_Pixels , whose value is |j - i| (Pixels). Then, convert the number of pixels to a distance as the width of the halo in the horizontal direction.

[0161] Similarly, repeat the same measurement steps to obtain the width of the halo in the vertical direction. Finally, the maximum luminance of the halo of the Mini-LED zoned backlight display screen is Lhalo Max , and the maximum width is Whalo Max , and the value of Whalo Max corresponds to the larger value of the halo widths in the horizontal and vertical directions. At this time, the measurement of the maximum halo of the Mini-LED zoned backlight display screen is completed.

[0162] The present invention discloses a method and system for measuring the maximum halo of a Mini-LED zoned backlight display screen; the present invention first builds a halo measurement device in a dark environment, secondly uses an optimal display white box size optimization method to find the display white box size corresponding to the maximum luminance of the display white box, then uses an optimal display white box position optimization module to find the display white box position corresponding to the maximum halo width of the display white box, then measures the found maximum halo effect situation in a dark environment, and finally simulates and reproduces the two-dimensional halo field distribution to obtain the maximum halo luminance and maximum halo width corresponding to the halo effect. After adopting the method of the present invention, the maximum halo situation of any Mini-LED display screen can be found and measured, and at the same time, the static halo is quantitatively analyzed, so as to effectively improve the precision and accuracy of the halo effect test of the Mini-LED display screen.

Claims

1. A method for measuring the maximum halo of a Mini-LED zoned backlight display screen, characterized in that, It includes the following steps: (1) Set up a halo measurement device in a dark environment; (2) Measure the brightness of display white boxes with different sizes on the Mini-LED zone-backlight display screen in a darkroom environment, and finally obtain the maximum display white box brightness and the corresponding display white box size; (3) Measure the halo conditions by pixel-level moving of the white boxes with the sizes determined in step (2) and measure the halos of white boxes at different positions on the Mini-LED zone-backlight display screen in a darkroom environment, and finally obtain the maximum halo width and the corresponding white box position; (4) After determining the display white box size and position, mask the display white box area and use an imaging luminance meter to take pictures and measure to obtain the halo brightness distribution in a darkroom environment; (5) According to the obtained halo brightness data in a darkroom environment, simulate and reproduce the halo to obtain the two-dimensional field distribution formula of the halo, and inversely deduce the maximum halo brightness parameter and the halo width parameter through the formula to complete the maximum halo measurement; Step (3) includes the following steps: (3.1) Let the backlight partition size of the Mini-LED partition backlight display screen be a pixel points. Set the display white box to move first in the horizontal X direction. Let the initial position of the display white box be the center position of the display screen, and the coordinates (x0, y0) of the upper left corner pixel be (W Max / 2 - W n , H Max / 2 - H n ). Set the motion step sizes of the white box as Δx and Δy to be a / 10; the gray level of the white box is the full gray level, and the gray level of other areas of the display screen is 0; set the number of iterations T x with the initial value of 0; W Max and H Max are the horizontal resolution and vertical resolution of the measured Mini-LED partition backlight display screen respectively, and W n and H n are the horizontal pixels and vertical pixels of the display white box respectively; (3.2) The imaging luminance meter measures the luminance values of all pixel points on the Mini-LED zoned backlight display screen when the coordinate of the pixel position in the upper left corner of the white box is (x0, y0) in a dark room environment. Process the luminance values of all pixel points on the display screen, extract the luminance values of the halo around the white box area on the display screen, and extract the luminance values in a single direction of the halo to obtain the luminance distribution in a single direction of the halo, and calculate the pixel distance between the point with the maximum luminance value of the halo and the 0.001 cd / m 2 luminance value point, which is the halo width denoted as D x_0 , and at the same time, the iteration number T x is incremented by one, and at this time, it is regarded as the completion of the first measurement; After completing the first measurement, control the white box on the screen to move one step horizontally. At this time, the pixel coordinates of the upper left corner of the white box are (x1, y0), where the values of x1 and y0 are x0 + Δx and y0 respectively; and repeat the same measurement steps as in step (3.2), and obtain the halo width D corresponding to the upper left corner coordinates of the white box at (x1, y0). x_1 , which is regarded as the completion of the second measurement at this time; make a judgment at this time: if D x_1 < D x_0 , then continue to execute the iteration and conduct the test; if D x_1 > D x_0 and there is a steep increase in the halo width, then stop the iteration, D x_1 is the maximum halo width of the corresponding display screen, and (x1, y0) is the pixel coordinates of the upper left corner corresponding to the display white box. (3.4) Continuously perform iteration and judgment. When the nth measurement occurs, where D x_0 > D x_1 > D x_2 > D x_3 > …… > D x_n-1 < D x_n > D x_n+1 > D x_n+2 > ……, at the nth measurement, when there is a sudden increase in the halo width, stop the iteration. D x_n is the maximum halo width of the corresponding display screen. (x n , y0) is the pixel coordinate of the upper left corner corresponding to the display white box, where x n and y0 are x0 + n·Δx and y0 respectively; at this time, it is regarded as finding the maximum width halo on one side in the horizontal X direction. After finding the maximum width halo on one side in the horizontal X direction, keep the horizontal position unchanged, that is, the x coordinate of the upper left corner pixel point n remains unchanged. Switch the display of the white box to move in the vertical Y direction by pressing a button, and repeat the same measurement steps as in step (3.2), step (3.3), and step (3.4) to find the maximum width halo D on one side in the horizontal Y direction y_m . At this time, the white box shows that the maximum width halos D are found on one side in the horizontal and vertical directions respectively x_n and D y_m . At this time, the coordinates of the upper left corner pixel point corresponding to the white box are (x n , y m ), where x n and y m are x0 + n·Δx and y0 + n·Δy respectively.

2. The method for measuring the maximum halo of a Mini-LED zoned backlight display screen according to claim 1, characterized in that: In the step (1), the surface brightness of the object in the darkroom environment is less than 0.001 cd / m 2 , and except for the Mini-LED backlight display screen, the rest of the light-emitting bodies are covered with an opaque and non-reflective black cloth; The halo measurement device includes a test platform, a Mini-LED zone-backlight display screen, a host for transmitting an image source to the Mini-LED zone-backlight display screen, an imaging luminance meter for measuring the zone-backlight display screen and related fixing devices, and a host for outputting halo brightness distribution data; among them, place the Mini-LED zone-backlight display screen to be measured at one end of the test platform, fix the imaging luminance meter on the cloud platform and place it at the other end of the platform, and place it in a suitable position so that the Mini-LED zone-backlight display screen to be measured appears completely and clearly in the field of view captured by the imaging luminance meter.

3. The measurement method of the maximum halo of a Mini-LED zoned backlight display screen according to claim 1, characterized in that: Step (2) includes the following steps: (2.1) Set the initial dimensions W0 and H0 of the display white box to W Max / 100 and H Max / 100; set the growth step sizes ΔW and ΔH of the length and width of the white box to W Max / 100 and H Max / 100; the initial display position of the white box is the center position of the display screen, the gray level of the white box is full gray level, and the gray level of other areas of the display screen is 0; set the initial value of the iteration number T to 0; (2.2) The imaging luminance meter measures the luminance values of all pixel points on the Mini-LED zoned backlight display screen when displaying the initial size white box in a dark room environment, processes the luminance values of all pixel points on the display screen, and extracts the luminance values of all pixel points in the white box area displayed on the display screen. There is glare and halo around the white box area displayed, and the luminance distribution of the backlight display screen when the light-emitting area of the Mini-LED zoned backlight display screen is not blocked is obtained, and the maximum luminance is denoted as L 0_Max , and at the same time, the iteration number T is incremented by one. At this time, it is regarded as the completion of the first measurement; After completing the first measurement, change the size of the display white box on the display screen. At this time, the size of the display white box is W1 and H1, where the values of W1 and H1 are W0 + ΔW and H0 + ΔH respectively; and repeat the same measurement steps as in step (2.2), and obtain the maximum brightness L corresponding to the white box sizes of W1 and H1 1_Max , and this is regarded as completing the second measurement; at this time, make a judgment: if L 1_Max > L 0_Max , then continue to execute the iteration and conduct the test; if L 1_Max < L 0_Max , then stop the iteration, and L 0_Max is the maximum brightness of the corresponding display screen, and W0 and H0 are the sizes corresponding to the display white box; (2.4) Continuously perform iteration and judgment. When the nth measurement occurs, where L 0_Max <L 1_Max <L 2_Max <L 3_Max <……<L n_Max <L n+1_Max <L n+2_Max <……, then stop the iteration. L n_Max is the maximum brightness of the corresponding display screen, and W n and H n are W0 + n·ΔW and H0 + n·ΔH respectively.

4. The method for measuring the maximum halo of a Mini-LED zoned backlight display screen according to claim 1, wherein: Step (4) includes the following steps: (4.1) Make an opaque and non-reflective mask, use the mask to block the light-emitting area of the display white box on the backlight display, and eliminate the influence of the glare generated by the light-emitting area of the display white box on the halo brightness value; the size of the mask completely covers the light-emitting area of the display white box and is 1-2 pixel points larger than the surrounding of the light-emitting area; (4.2) Use an imaging luminance meter to measure the brightness values of all pixel points on the Mini-LED zone-backlight display screen when displaying the white box in a darkroom environment, repeat the measurement at least five times, remove the maximum and minimum data, and take the average of the remaining data; export the halo brightness distribution data of the Mini-LED zone-backlight display screen in a darkroom environment.

5. The measuring method for the maximum halo of a Mini-LED zoned backlight display screen according to claim 1, wherein: Step (5) includes the following steps: (5.1) Extract the one-dimensional brightness distribution data horizontally and vertically from the exported halo brightness distribution data of the Mini-LED zone-backlight display screen in a darkroom environment, and perform median filtering on the extracted one-dimensional brightness distribution data to filter out stray light noise; the extracted halo data follows a Gaussian distribution in the horizontal and vertical directions; by fitting the filtered horizontal and vertical pixel one-dimensional data with a Gaussian distribution, the specific fitting expression is as follows: The best-fit parameters a1 and σ1 are obtained to get the one-dimensional Gaussian distribution formulas of the halos in the horizontal and vertical pixels respectively; where a1 represents the peak brightness of the halo in a single direction, σ1 determines the area or size of the halo, and σ1 represents the Mini-LED backlight zoning situation; (5.2) Combine the one-dimensional Gaussian distribution formulas of the horizontal and vertical pixels to construct the two-dimensional field distribution expression of the halo of the Mini-LED zoned backlight display screen in a darkroom environment: where Lhalo Max represents the maximum brightness value of the halo, where dy = min(|i - up|, |j - down|), dx = min(|i - left|, |j - right|), up, down, left, and right are the upper, lower, left, and right boundary coordinates of the white box respectively, where dxc is the distance of the pixel point to the center of the white box in the horizontal direction, dyc is the distance of the pixel point to the center of the white box in the vertical direction, where σ1 represents the depth distribution width of the halo, where σ2 represents the horizontal distribution width of the halo, and σ1 and σ2 determine the area or size of the halo; (5.3) According to the two-dimensional field distribution expression of the halo of the Mini-LED zoned backlight display screen derived by fitting, simulate and reproduce the halo of the Mini-LED zoned backlight display screen, and extract the one-dimensional brightness distribution data Data_x and Data_y of the unilateral simulated halo in the horizontal and vertical directions respectively through the central symmetry point; (5.4) Through the extracted one-dimensional brightness distribution data Data_x of the unilateral simulated halo, find the pixel point Lhalo with the maximum halo brightness value Lhalo Max and brightness value is 0.001cd / m 2 The pixel point Lhalo at the edge of the halo 0.001 , where the pixel with the maximum brightness of the halo is Lhalo Max The corresponding data is the i-th bit in the distribution data Data_x, the halo edge pixel Lhalo 0.001 Corresponding to the j-th bit data in the distribution data Data_x, the number of pixels between the halo maximum brightness pixel and the halo edge pixel is determined to be W Halo_Pixels , whose value is |ji|, and then the number of pixels is converted into distance as the width of the halo in the horizontal direction. The specific conversion formula is: W Halo_mm = W Halo_Pixels / Width Box_Pixels * Width Box_mm Among them, W Halo_mm is the maximum millimeter width of the halo to be obtained, W Halo_Pixels is the maximum pixel width of the halo captured by the luminance meter, Width Box_Pixels is the maximum pixel width of the halo captured by the luminance meter, Width Box_mm is the maximum millimeter width of the halo on the display screen under test; (5.5) Similarly, by repeating the same measurement steps as in step (5.4), the width of the halo in the vertical direction can be obtained; finally, the maximum brightness of the halo of the Mini-LED zoned backlight display screen is Lhalo Max , and the maximum width is Whalo Max , where the value corresponds to the larger of the horizontal and vertical widths, completing the halo measurement.

6. A measurement system for the maximum halo of a Mini-LED zoned backlight display screen based on the measurement method according to any one of claims 1-5, characterized in that, It includes the following steps: The halo measurement device building module in the dark environment is used for building the darkroom environment, building the measurement device and the relevant preparations before measurement; The optimal display white box size optimization module is used to measure the brightness of the display white box area of the Mini-LED zoned backlight display screen in the darkroom environment, and iteratively measure the brightness corresponding to different sizes of the display white box to finally obtain the size of the display white box corresponding to the maximum display white box brightness; The optimal display white box position optimization module is used to move the white box at the pixel level and measure the halo situation for the determined-size white box, measure the halo of the white box at different positions of the Mini-LED zoned backlight display screen in the darkroom environment, and determine the position of the white box corresponding to the maximum halo width; The maximum halo measurement module is used to, after determining the size and position of the display white box, perform masking processing on the display white box area and take pictures and measurements with an imaging luminance meter to obtain the halo brightness distribution in the darkroom environment; The two-dimensional halo field distribution simulation and reproduction module is used to measure the halo brightness data obtained in the darkroom environment, simulate and reproduce the halo to obtain the two-dimensional field distribution formula of the halo, and inversely deduce the maximum halo brightness parameter and the halo width parameter through the formula.

7. A measurement system for the maximum halo of a Mini-LED zoned backlight display screen according to claim 6, characterized in that: In the optimal display white box size optimization module, a Python program is applied, and the code has the following functions: reading the resolution of the measured Mini-LED zoned backlight display screen; realizing pixel-level display control of the measured Mini-LED zoned backlight display screen; realizing button input to control the change of the white box size of the Mini-LED zoned backlight display screen; Design an optimal display white box size iterative optimization method: Assume the resolution of the Mini-LED zoned backlight display screen under test is W Max and H Max . Set the initial sizes W0 and H0 of the display white box to be W Max / 100 and H Max / 100 respectively; set the growth steps ΔW and ΔH of the white box length and width to be W Max / 100 and H Max / 100 respectively; the initial display position of the white box is the center position of the display screen, the gray level of the white box is full gray level, and the gray level of other areas of the display screen is 0; set the initial value of the iteration number T to be 0; The imaging luminance meter measures the luminance values of all pixel points on the display screen when the Mini-LED zoned backlight display screen shows the initial size white box in a dark room environment, processes the luminance values of all pixel points on the display screen, and extracts the luminance values of all pixel points in the white box area shown on the display screen. There is glare and halo around the white box area shown, and the luminance distribution of the backlight display screen when the light-emitting area of the Mini-LED zoned backlight display screen is not blocked is obtained, and the maximum luminance is denoted as L 0_Max , and at the same time, the iteration number T is incremented by one. At this time, it is regarded as the completion of the first measurement; After completing the first measurement, the display white box size on the display screen is changed by pressing the keyboard control program. At this time, the size of the display white box is W1 and H1, where the values of W1 and H1 are W0 + ΔW and H0 + ΔH respectively; and repeat the same measurement steps, and obtain the maximum brightness L corresponding to the white box sizes of W1 and H1 1_Max , and this is regarded as completing the second measurement; at this time, make a judgment: if L 1_Max > L 0_Max , then continue to execute the iteration and conduct the test; if L 1_Max < L 0_Max , then stop the iteration, and L 0_Max is the maximum brightness of the corresponding display screen, and W0 and H0 are the sizes corresponding to the display white box; Continuously perform iteration and judgment. When the nth measurement occurs, where L 0_Max <L 1_Max <L 2_Max <L 3_Max <……<L n_Max <L n+1_Max <L n+2_Max <……, then stop the iteration. L n_Max is the maximum brightness of the corresponding display screen, and W n and H n are W0 + n·ΔW and H0 + n·ΔH respectively.

8. A measurement system for the maximum halo of a Mini-LED zoned backlight display screen according to claim 7, characterized in that: In the optimal display white box position optimization module, based on the Python program of the optimal display white box size optimization module, the following functions are added: realizing the movement of the white box on the Mini-LED zoned backlight display screen according to the set movement step length and set direction; realizing the button input to control the setting of the movement step length and movement direction of the white box on the Mini-LED zoned backlight display screen; realizing the button control to record the movement, direction and the pixel coordinates of the upper left corner of the white box on the Mini-LED zoned backlight display screen. Optimal display white box position iterative optimization method: Assume that the backlight partition size of the Mini-LED partition backlight display screen is a pixel points. Set the display white box to move first in the horizontal X direction. Assume that the initial position of the display white box is the center position of the display screen, and the coordinates (x0, y0) of its upper left corner pixel are (W Max / 2 - W n , H Max / 2 - H n ). Set the motion step sizes of the white box as Δx and Δy to be a / 10; the gray level of the white box is full gray level, and the gray level of other areas of the display screen is 0; set the initial value of the iteration number T x to be 0; The imaging luminance meter measures the luminance values of all pixel points on the Mini-LED zoned backlight display screen in a dark room environment when the pixel position coordinates at the upper left corner of the white box are (x0, y0). It processes the luminance values of all pixel points on the display screen, extracts the luminance values of the halo around the white box area on the display screen, and extracts the luminance values in a single direction of the halo to obtain the luminance distribution in a single direction of the halo, and calculates the pixel distance between the point with the maximum luminance value of the halo and the 0.001 cd / m 2 The luminance value point is the halo width, denoted as D x_0 , and at the same time, the iteration count T x is incremented by one. At this time, it is regarded as the completion of the first measurement; After completing the first measurement, press the keyboard to control the white box on the screen to move one step horizontally. At this time, the pixel coordinates of the upper left corner of the white box are (x1, y0), where the values of x1 and y0 are x0 + Δx and y0 respectively; and repeat the same measurement steps, and obtain the halo width D corresponding to the upper left corner coordinates of the white box at (x1, y0). x_1 , which is regarded as the completion of the second measurement at this time; make a judgment at this time: if D x_1 < D x_0 , then continue to execute the iteration and conduct the test; if D x_1 > D x_0 and there is a sharp increase in the halo width, then stop the iteration, D x_1 is the maximum halo width of the corresponding display screen, and (x1, y0) is the pixel coordinates of the upper left corner corresponding to the display white box; Continuously perform iteration and judgment. When the nth measurement occurs, where D x_0 > D x_1 > D x_2 > D x_3 > …… > D x_n-1 < D x_n > D x_n+1 > D x_n+2 > ……, at the nth measurement, a sudden increase in the halo width occurs, then stop the iteration. D x_n is the maximum halo width of the corresponding display screen. (x n , y0) is the pixel coordinate of the upper left corner corresponding to the display white box, where x n and y0 are x0 + n·Δx and y0 respectively; at this time, it is regarded as finding the maximum width halo on one side in the horizontal X direction. After finding the maximum-width single-sided halo in the horizontal X direction, ensure that the horizontal position remains unchanged, i.e., the x coordinate of the upper-left pixel point n remains unchanged. By pressing the key to switch the display, the white box moves in the vertical Y direction, and repeat the same measurement steps to find the maximum-width single-sided halo D in the horizontal Y direction y_m . At this time, the white box shows that the maximum-width halos D are found on one side in the horizontal and vertical directions respectively x_n and D y_m . At this time, the coordinates of the upper-left pixel point corresponding to the white box are (x n , y m ), where x n and y m are x0 + n·Δx and y0 + n·Δy respectively.

9. A measurement system for the maximum halo of a Mini-LED zoned backlight display screen according to claim 6, wherein: In the two-dimensional halo field distribution simulation and reproduction module, the exported halo brightness distribution data of the Mini-LED zoned backlight display screen in the darkroom environment is respectively extracted into one-dimensional brightness distribution data in the horizontal and vertical directions, and the extracted one-dimensional brightness distribution data is subjected to median filtering to filter out stray light noise; the extracted halo data follows a Gaussian distribution in the horizontal and vertical directions; by fitting the filtered one-dimensional data of horizontal and vertical pixels with a Gaussian distribution, the one-dimensional Gaussian distribution formulas of the halo in the horizontal and vertical pixels are obtained. The one-dimensional Gaussian distribution formulas of the horizontal and vertical pixels are combined to construct an expression of the two-dimensional field distribution of the halo of the Mini-LED zoned backlight display screen in the darkroom environment. According to the expression of the two-dimensional field distribution of the halo of the Mini-LED zoned backlight display screen derived by fitting, the halo of the Mini-LED zoned backlight display screen is simulated and reproduced, and the one-dimensional brightness distribution data Data_x and Data_y of the unilateral simulated halo are respectively extracted in the horizontal and vertical directions through the central symmetry point. By extracting the one-dimensional brightness distribution data Data_x of the unilateral simulated halo, find the pixel point Lhalo with the largest halo brightness value Lhalo (nits) Max and brightness value is 0.001cd / m 2 The pixel point Lhalo at the edge of the halo 0.001 , where the pixel with the maximum brightness of the halo is Lhalo Max The corresponding data is the i-th bit in the distribution data Data_x, the halo edge pixel Lhalo 0.001 Corresponding to the j-th bit data in the distribution data Data_x, the number of pixels between the halo maximum brightness pixel and the halo edge pixel is determined to be W Halo_Pixels , its value is |ji|(Pixels), and then the number of pixels is converted into distance as the width of the halo in the horizontal direction; Repeat the same measurement steps to obtain the width of the halo in the vertical direction; finally, the maximum brightness of the halo of the Mini-LED zone-backlight display screen is obtained as Lhalo Max , and the maximum width is Whalo Max , and its value corresponds to the larger of the widths in the horizontal and vertical directions. At this time, the measurement of the maximum halo of the Mini-LED zone-backlight display screen is completed.

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