A low-latency Mini LED backlight control method and system

Abstract

The application discloses a low-delay Mini LED backlight control method and system, and belongs to the technical field of LED backlight, and comprises the following steps: obtaining each low-gray-scale luminance region; obtaining a low-gray-scale luminance distortion judgment result and each low-gray-scale luminance distortion region; obtaining a PWM duty cycle correction factor of each low-gray-scale luminance distortion region, thereby performing PWM duty cycle iterative adjustment, obtaining a PWM duty cycle iterative adjustment judgment result, and if the PWM duty cycle iterative adjustment judgment result is qualified, the processing is completed, otherwise, exposure duration adjustment is performed; obtaining a halo judgment result, if the halo judgment result is qualified, halo improvement processing is not performed, otherwise, halo improvement processing is performed; the Mini LED backlight restores the luminance distortion and halo influence in the low-gray-scale scene accurately, and solves the problems of low-gray-scale luminance distortion and halo caused by the edge mutation of the partition due to insufficient control precision in the prior art.

Description

Technical Field

[0001] This invention relates to the field of LED backlight technology, and in particular to a low-latency Mini LED backlight control method and system. Background Technology

[0002] Existing Mini LED backlight control systems acquire image RGB data, process the color components, extract brightness data, correct and map the backlight values ​​to generate driving data, and then output the data to the LCD panel and backlight to achieve driving and brightness control of the Mini LED backlight.

[0003] For example, Chinese invention patent CN114495842B discloses a liquid crystal display device and driving method based on a Mini LED backlight and local dimming, including: acquiring an image RBG data stream; processing each color component of the image RBG data stream; performing an RBG-to-YCbCr conversion operation on the image RBG data stream to extract the image brightness data stream; correcting the backlight values; mapping the 8-bit backlight values ​​to obtain 12-bit driving values; and outputting the processed image RBG data stream to the display section of the liquid crystal display device. The driving values ​​are also output to the backlight panel.

[0004] For example, Chinese invention patent CN116453471A discloses a channel current control device and method for a mini LED backlight, comprising: a control unit for providing a corresponding reference voltage signal, a pulse width modulation signal, and a digital current setting signal to each mini LED channel in the mini LED backlight; and for each mini LED channel, the channel current control device includes: a constant current control unit, a high-voltage transistor, and a low-voltage transistor, wherein the high-voltage transistor is connected in series between multiple LEDs and the low-voltage transistor in the mini LED channel, and the gate of the high-voltage transistor receives the pulse width modulation signal; the input terminal of the constant current control unit receives the reference voltage signal, the pulse width modulation signal, and the digital current setting signal, and the output terminal of the constant current control unit is connected to the low-voltage transistor, so as to realize current regulation and constant current control of the mini LED channel.

[0005] However, in the process of implementing the inventive technical solution in the embodiments of this application, it was found that the above-mentioned technology has at least the following technical problems:

[0006] In existing technologies, when controlling Mini LED backlights, the focus is usually only on mapping and adjusting the overall image brightness. However, low grayscale brightness areas are not sensitive to current response and have low adjustment precision, making them prone to brightness distortion that deviates from the target value. At the same time, if there is a large brightness change between adjacent light-controlled areas, it is easy to form a halo effect, which seriously affects the uniformity of display and the image quality experience. Therefore, there are problems of low grayscale brightness distortion and halo caused by sudden changes at the edge of the partition due to insufficient control precision. Summary of the Invention

[0007] To address the problems of low grayscale brightness distortion and halo effects caused by abrupt changes in partition edges due to insufficient control precision in existing technologies, this invention provides a low-latency Mini LED backlight control method and system. The technical solution is as follows:

[0008] On the one hand, a low-latency Mini LED backlight control method is provided. This method includes: a Mini LED central processing unit retrieving the current image frame and dividing the light control area to obtain each light control area; filtering the brightness of each light control area to obtain each low grayscale brightness area; acquiring the actual brightness value of each low grayscale brightness area and comparing it with the target brightness value to obtain a low grayscale brightness distortion judgment result and each low grayscale brightness distortion area; acquiring the brightness distortion influence parameters of each low grayscale brightness distortion area, analyzing the PWM duty cycle correction factor of each low grayscale brightness distortion area, and performing iterative adjustment of the PWM duty cycle to obtain a PWM duty cycle iterative adjustment judgment result; if the PWM duty cycle iterative adjustment judgment result is qualified, the processing is completed; otherwise, the exposure time is adjusted; acquiring the brightness difference between adjacent low grayscale brightness distortion areas after distortion improvement adjustment, and analyzing the halo judgment result; if the halo judgment result is qualified, halo improvement processing is not performed; otherwise, halo improvement processing is performed; the distortion improvement adjustment includes PWM duty cycle iterative adjustment and exposure time adjustment.

[0009] On the other hand, a low-latency Mini LED backlight control system is provided, which includes: a low grayscale brightness area determination module, a low grayscale brightness distortion area screening module, a distortion improvement adjustment module, and a halo improvement processing module; wherein, the low grayscale brightness area determination module is used for Mini The LED central processing unit retrieves the current image frame and divides the light control area to obtain each light control area. Each light control area is then filtered for brightness to obtain low grayscale brightness areas. A low grayscale brightness distortion area filtering module obtains the actual brightness value of each low grayscale brightness area and compares it with the target brightness value to obtain the low grayscale brightness distortion judgment result and each low grayscale brightness distortion area. A distortion improvement and adjustment module obtains the brightness distortion influence parameters of each low grayscale brightness distortion area, analyzes and obtains the PWM duty cycle correction factor for each low grayscale brightness distortion area, and performs iterative adjustment of the PWM duty cycle to obtain the PWM duty cycle iterative adjustment judgment result. If the PWM duty cycle iterative adjustment judgment result is qualified, the processing is completed; otherwise, the exposure time is adjusted. A halo improvement processing module obtains the brightness difference between adjacent low grayscale brightness distortion areas after distortion improvement and analysis to obtain the halo judgment result. If the halo judgment result is qualified, halo improvement processing is not performed; otherwise, halo improvement processing is performed. Distortion improvement and adjustment includes PWM duty cycle iterative adjustment and exposure time adjustment.

[0010] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following:

[0011] 1. The low-latency Mini LED backlight control method provided by this invention achieves accurate identification and graded adjustment of low grayscale brightness distortion and halo problems by dividing the light control area, identifying low grayscale brightness areas, determining brightness distortion, and analyzing halo based on image frames. This enables accurate restoration of the brightness distortion and halo effects of Mini LED backlight in low grayscale scenarios, effectively solving the problem of low grayscale brightness distortion and halo caused by abrupt changes in partition edges due to insufficient control precision in the prior art.

[0012] 2. This invention obtains the brightness distortion influence value by analyzing the brightness distortion influence parameters, and then obtains the PWM duty cycle correction factor based on the brightness distortion influence value and the database. This enables differentiated adjustment for different distortion regions, effectively improving the accuracy and consistency of low grayscale brightness control.

[0013] 3. This invention obtains the halo adjustment influence value by analyzing the halo adjustment influence parameters of adjacent low grayscale light control areas, and determines the brightness adjustment influence factor by combining the brightness difference change trend, thereby obtaining the actual width of edge blending, and thus realizing dynamic correction control of the boundary halo intensity, thereby effectively improving the halo transition problem between light control areas and improving the naturalness and uniformity of the image edge display.

[0014] 4. This invention identifies low grayscale brightness areas by setting a minimum controllable brightness threshold and comparing and filtering the target brightness values ​​of each light-controlled area. Then, it obtains the distortion area through difference analysis and brightness difference threshold determination, and further subdivides it into overly bright and overly dark distortion areas. This provides a basic zoning basis for subsequent targeted adjustments, avoiding large-scale misadjustment or error spread in areas with insufficient brightness accuracy, and improving the adjustment efficiency and stability of the Mini LED backlight system under low grayscale brightness control. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A flowchart of a low-latency Mini LED backlight control method provided in this application embodiment;

[0017] Figure 2 A macroscopic flowchart of a low-latency Mini LED backlight control method provided in an embodiment of this application;

[0018] Figure 3 A flowchart illustrating the exposure duration adjustment of a low-latency Mini LED backlight control method provided in this application embodiment;

[0019] Figure 4 A schematic diagram of a low-latency Mini LED backlight control system provided in this application embodiment;

[0020] Figure 5 A schematic diagram of low grayscale region analysis of a low-latency Mini LED backlight control system provided in an embodiment of this application;

[0021] Figure 6 A magnified schematic diagram of the low grayscale distortion detection result of a low-latency Mini LED backlight control system provided in an embodiment of this application;

[0022] Figure 7 A schematic diagram of the low grayscale distortion area position display of a low-latency Mini LED backlight control system provided in an embodiment of this application;

[0023] Figure 8This is a comparative schematic diagram showing the correction and adjustment effect of the low grayscale distortion area in a low-latency Mini LED backlight control system provided in an embodiment of this application. Detailed Implementation

[0024] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0025] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0026] In the embodiments of this invention, the terms "image" and "picture" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning. Similarly, the terms "of," "corresponding (relevant)," and "corresponding" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning.

[0027] In this embodiment of the invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meaning they express is the same.

[0028] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0029] like Figure 1The diagram shows a flowchart of a low-latency Mini LED backlight control method provided in this application embodiment. The method includes the following steps: The Mini LED central processing unit retrieves the current image frame and divides the light control area to obtain each light control area. The brightness of each light control area is filtered to obtain each low grayscale brightness area. The actual brightness value of each low grayscale brightness area is obtained and compared with the target brightness value to obtain the low grayscale brightness distortion judgment result and each low grayscale brightness distortion area. The brightness distortion influence parameters of each low grayscale brightness distortion area are obtained, and the PWM duty cycle correction factor of each low grayscale brightness distortion area is analyzed. The PWM duty cycle is iteratively adjusted to obtain the PWM duty cycle iterative adjustment judgment result. If the PWM duty cycle iterative adjustment judgment result is qualified, the processing is completed; otherwise, the exposure time is adjusted. The brightness difference between each adjacent low grayscale brightness distortion area after distortion improvement adjustment is obtained and analyzed to obtain the halo judgment result. If the halo judgment result is qualified, halo improvement processing is not performed; otherwise, halo improvement processing is performed. The distortion improvement adjustment includes PWM duty cycle iterative adjustment and exposure time adjustment.

[0030] In this embodiment, it should be noted that all differences obtained by the difference processing are positive values.

[0031] like Figure 2 As shown, Figure 2 This is a macroscopic flowchart of a low-latency Mini LED backlight control method provided in an embodiment of this application. The Mini LED central processing unit retrieves the current image frame and analyzes it to obtain each light control area. The brightness of each light control area is filtered to obtain each low grayscale brightness area. Distortion judgment is performed on each low grayscale brightness area to obtain the low grayscale brightness distortion judgment result and each low grayscale brightness distortion area. The brightness distortion influence parameters of each low grayscale brightness distortion area are obtained. The PWM duty cycle correction factor of each low grayscale brightness distortion area is analyzed to obtain the PWM duty cycle iterative adjustment. The PWM duty cycle iterative adjustment judgment result is obtained. If the PWM duty cycle iterative adjustment judgment result is qualified, the processing is completed; otherwise, the exposure time is adjusted, and the halo judgment result is obtained after processing. If the halo judgment result is qualified, halo improvement processing is not performed; if the halo judgment result is unqualified, halo improvement processing is performed, thus completing the process.

[0032] It should be noted that PWM is an abbreviation for Pulse Width Modulation, specifically referring to a dimming method used to control the brightness output of Mini LED backlights. During the image quality inspection process before LCD TVs leave the factory, in low grayscale scenes (such as night scenes, rainy night scenes, and other dark detail images), the Mini LED backlight often suffers from image distortion due to insufficient control precision under low brightness drive. This manifests as overexposure or underexposure in low grayscale levels. The main causes of this distortion include: insufficient PWM duty cycle adjustment resolution at low grayscale levels, resulting in excessively high or low brightness output; insufficient initial drive current or excessively large minimum current step size, causing some areas of LEDs to be ineffectively driven; and large brightness differences between adjacent zones and poor edge blending, further leading to halo interference and abrupt brightness changes between areas. To address the aforementioned issues, this solution introduces a method for determining and correcting low grayscale brightness distortion regions. By analyzing parameters such as brightness difference, target grayscale, initial drive current, and PWM duty cycle, the distortion type and region range are determined. Based on the actual width of edge blending, the brightness is progressively adjusted to obtain a reasonable PWM duty cycle correction factor. This achieves compensation and adjustment of the distortion region, effectively improving the brightness control accuracy of Mini LED in low grayscale image scenarios, ensuring image detail and display consistency, and avoiding display anomalies such as halos, whitening, and black blocking.

[0033] The Mini LED central processing unit retrieves the current image frame and divides it into light control areas to obtain each light control area. The specific method is as follows: The Mini LED central processing unit retrieves the current image frame and obtains the resolution of the current image frame (e.g., 1920×1080 resolution). It matches the resolution of the current image frame with the preset resolution in the database. If the resolution of the current image frame is the same as the preset resolution in the database, it obtains the partition layout (e.g., 32×18 partitions) corresponding to that resolution and divides it to obtain each light control area.

[0034] like Figure 5 , Figure 6 , Figure 7 As shown, Figure 5 A schematic diagram of low grayscale region analysis for a low-latency Mini LED backlight control system provided in this application embodiment. Figure 6 A magnified schematic diagram of the low grayscale distortion detection results of a low-latency Mini LED backlight control system provided in this application embodiment.

[0035] Figure 7This application provides a schematic diagram of a low-grayscale distortion area location display for a low-latency Mini LED backlight control system. As shown in the diagram, by dividing the image displayed on the Mini LED screen into several regions (e.g., 32×18 zones) and analyzing them, the brightness value of each region, the distortion type corresponding to each grayscale distortion region, and the location coordinates of the distortion region corresponding to each distortion type can be obtained. The diagram also shows the model name of the device used for distortion detection and its corresponding resolution.

[0036] Furthermore, the low grayscale brightness regions are obtained by: obtaining the target brightness value of each light-controlled region; obtaining the preset minimum controllable brightness threshold in the database and comparing it with the target brightness value of each light-controlled region; if the target brightness value of a certain light-controlled region is less than the minimum controllable brightness threshold, then the light-controlled region is marked as a low grayscale brightness region, thereby statistically obtaining each low grayscale brightness region.

[0037] In this embodiment, it should be noted that the target brightness value of the light-controlling area is the ideal display brightness value of the corresponding image frame to be displayed, and each light-controlling area has a corresponding target brightness value. The minimum controllable brightness refers to the lower limit of the minimum brightness value that the system can stably control and output in a Mini LED backlight system.

[0038] In the process of fine-tuning Mini LED backlight, low grayscale brightness areas are prone to brightness distortion because their target brightness values ​​are close to the system's minimum controllable brightness and are affected by factors such as driving accuracy, current control step size, and system response errors. Therefore, this solution compares the target brightness values ​​of each light-controlled area with the preset minimum controllable brightness threshold to identify and delineate low grayscale brightness areas with potential brightness output risks in advance. On the one hand, this allows subsequent complex adjustment logics such as brightness distortion analysis, PWM duty cycle adjustment, and exposure correction to focus on areas with real potential problems, avoiding performance waste and misjudgment caused by uniform processing of the entire area, thereby improving processing efficiency and response speed. On the other hand, by structurally marking low grayscale brightness areas, a clear target area basis can be provided for subsequent distortion adjustment and halo improvement, which is conducive to targeted adjustment, enhancing the stability and consistency of brightness control under low grayscale conditions, and suppressing distortion propagation and visual abnormalities at the source.

[0039] Furthermore, the low grayscale brightness distortion judgment results and each low grayscale brightness distortion region are obtained. The specific method is as follows: the actual brightness value of each low grayscale brightness region is obtained and the absolute difference is processed with the target brightness value to obtain the target brightness difference value of each low grayscale brightness region; the preset brightness difference threshold in the database is obtained and compared with the target brightness difference value of each low grayscale brightness region to obtain the low grayscale brightness distortion judgment result. If the target brightness difference value of a certain low grayscale brightness region is less than the brightness difference threshold, the low grayscale brightness distortion judgment result of that low grayscale brightness region is normal; otherwise, the low grayscale brightness distortion judgment result of that low grayscale brightness region is abnormal, and the low grayscale brightness region with the abnormal low grayscale brightness distortion judgment result is marked as a low grayscale brightness distortion region. Thus, each low grayscale brightness distortion region is statistically obtained; the brightness value of each low grayscale brightness distortion region is compared with the target brightness value, and the low grayscale brightness distortion region with a brightness value greater than the target brightness value is marked as a brighter distortion region, and the low grayscale brightness distortion region with a brightness value less than the target brightness value is marked as a darker distortion region.

[0040] In this embodiment, the actual brightness value of each low grayscale brightness area refers to the brightness value of each low grayscale brightness area that is actually displayed.

[0041] By performing absolute difference processing (taking the absolute value of the difference) between the actual brightness values ​​of each low grayscale brightness region and the target brightness value, and introducing a preset brightness difference threshold to determine whether brightness distortion exists, the deviation in brightness output can be effectively identified, thereby accurately dividing the low grayscale brightness distortion regions with display errors. By identifying these low grayscale brightness distortion regions, targeted adjustments can be made to these distorted regions, avoiding over-processing of distortion-free areas and improving overall efficiency. Further analysis of these low grayscale brightness distortion regions, subdividing them into overly bright and overly dark distortion regions, clarifies the direction and magnitude of subsequent adjustments. For overly bright regions, driving parameters can be appropriately reduced, while for overly dark regions, the light-emitting driving capability needs to be enhanced. This avoids blind adjustments, effectively improving the ability to restore low-brightness details and enhancing the sense of layering and consistency in the dark areas of the image.

[0042] Furthermore, the PWM duty cycle correction factor for each low grayscale brightness distortion region is determined as follows: Brightness distortion influence parameters for each low grayscale brightness distortion region are obtained, including the initial drive current, minimum current step size, system refresh frequency, and grayscale adjustment step size. A preset brightness distortion influence baseline set is obtained from the database and compared with the brightness distortion influence parameters for each low grayscale brightness distortion region to obtain the comparison analysis results. Based on the comparison analysis results, corresponding weighting factors are introduced for coupling processing to obtain the brightness distortion influence value for each low grayscale brightness distortion region. The brightness distortion influence value for each low grayscale brightness distortion region is matched with the database to obtain the PWM duty cycle correction factor for each low grayscale brightness distortion region. The brightness distortion influence baseline set includes the baseline values ​​of the initial drive current, minimum current step size, system refresh frequency, and grayscale adjustment step size.

[0043] In this embodiment, the initial drive current is the minimum current value used when driving the initial brightness of the control light-emitting area. The minimum current step size refers to the smallest unit of current change, which determines the fineness of brightness adjustment. The system refresh frequency refers to the frequency at which the backlight drive updates; the higher the frequency, the more timely the dimming response. The grayscale adjustment step size represents the precision of grayscale adjustment of the PWM signal; the smaller the step size, the finer the control. The initial drive current and the minimum current step size can be obtained by adjusting the registers of the Mini LED driver chip. The system refresh frequency can be read from the background of the control system, and the grayscale adjustment step size can be queried in the controller software configuration interface.

[0044] The method for obtaining the brightness distortion influence values ​​of each low grayscale brightness distortion region is as follows:

[0045] ;

[0046] In the formula, H Yi This represents the luminance distortion effect value of the i-th low grayscale luminance distortion region, where i represents the number of the low grayscale luminance distortion region, i=1,2,3,...,i max i max QI represents the total number of low-grayscale brightness distortion areas. i HQ represents the starting drive current of the i-th low grayscale brightness distortion region, and BI represents the baseline value of the starting drive current. i HB represents the minimum current step size for the i-th low grayscale brightness distortion region, and PI represents the baseline value of the minimum current step size. i The system refresh rate represents the i-th low grayscale brightness distortion region, HP represents the baseline value of the system refresh rate, and TI represents the system refresh rate. iHT represents the grayscale adjustment step size of the i-th low grayscale brightness distortion region, μ1 represents the starting drive current weighting factor, μ2 represents the minimum current step size weighting factor, μ3 represents the system refresh frequency weighting factor, and μ4 represents the grayscale adjustment step size weighting factor.

[0047] By analyzing the parameters affecting brightness distortion, including the initial drive current, minimum current step size, system refresh frequency, and grayscale adjustment step size, the brightness distortion impact values ​​of each low grayscale brightness distortion region are obtained. This is because the interrelationships between these parameters are taken into account. For example, the smaller the initial drive current, the lower the starting point of response to low grayscale signals, but the easier it is for insufficient current drive to lead to brightness loss; the larger the minimum current step size, the worse the dimming accuracy, which is prone to brightness jumps and exacerbates low grayscale errors; the lower the refresh frequency, the lower the time resolution of PWM dimming at low grayscale, resulting in reduced grayscale adjustment stability; the larger the grayscale adjustment step size, the coarser the brightness adjustment range, making it difficult to achieve linear transition at low grayscale.

[0048] The initial drive current weighting factor, minimum current step size weighting factor, system refresh frequency weighting factor, and grayscale adjustment step size weighting factor can be obtained from the database. For example, the initial drive current weighting factor can be obtained by analyzing the historical initial drive current set stored in the database. The difference between each historical initial drive current in the historical initial drive current set and the actual initial drive current is processed (the absolute value of the difference is taken) to obtain the difference between each historical initial drive current. A preset threshold range for the initial drive current difference in the database is obtained and compared with each historical initial drive current difference. If a historical initial drive current difference falls within the threshold range, the corresponding historical initial drive current is obtained and marked as the historical control initial drive current, thus obtaining each historical control initial drive current. The extreme values ​​of each historical control initial drive current are removed (maximum and minimum values ​​are removed), and the standard deviation is taken to obtain the standard deviation of the historical control initial drive current. The system retrieves preset historical reference starting drive current weighting factors, historical control starting drive current standard deviation benchmarks, historical starting drive current control standard deviation difference gradients, and single-level adjustment amounts of the starting drive current weighting factors from the database. It then performs difference processing between the historical control starting drive current standard deviation and the historical control starting drive current benchmark value to obtain the historical control starting drive current standard deviation difference value. Finally, it performs a multiple analysis on the historical control starting drive current standard deviation difference value and the historical starting drive current control standard deviation difference gradient (dividing the historical control starting drive current standard deviation difference value by the historical starting drive current control standard deviation difference gradient value) to obtain the historical starting drive current control standard deviation difference gradient multiple. The initial drive current weighting factor is obtained by multiplying the gradient multiple of the historical reference standard deviation difference by the single-level adjustment of the initial drive current weighting factor. This yields the comprehensive adjustment of the initial drive current weighting factor. The initial drive current standard deviation is compared to a historical reference standard deviation benchmark. If the historical reference standard deviation is greater than the benchmark, the historical reference initial drive current weighting factor is added to the comprehensive adjustment of the initial drive current weighting factor to obtain the final initial drive current weighting factor. Otherwise, the historical reference initial drive current weighting factor is subtracted from the comprehensive adjustment of the initial drive current weighting factor to obtain the final initial drive current weighting factor. The single-level adjustment of the initial drive current weighting factor refers to the adjustment required for each increase in the historical initial drive current reference standard deviation difference gradient. The historical initial drive current reference standard deviation difference gradient refers to the difference between the minimum values ​​of two adjacent gradient intervals. Other weighting factors, such as the minimum current step size weighting factor, system refresh rate weighting factor, and grayscale adjustment step size weighting factor, are obtained in the same way as the initial drive current weighting factor.

[0049] By comparing and analyzing the brightness distortion influence parameters with a preset baseline set, and by introducing a weighting factor to calculate the PWM duty cycle correction factor, the PWM duty cycle can be precisely adjusted according to the specific control characteristics of different distortion regions, thereby achieving more refined brightness control.

[0050] Furthermore, the PWM duty cycle is iteratively adjusted to obtain the PWM duty cycle iterative adjustment judgment result. Specifically, the PWM duty cycle is adjusted for each low grayscale brightness distortion region based on its PWM duty cycle correction factor. If a low grayscale brightness distortion region is a brighter distortion region, the PWM duty cycle is reduced based on the PWM duty cycle correction factor corresponding to that region. If a low grayscale brightness distortion region is a darker distortion region, the PWM duty cycle is reduced based on the PWM duty cycle correction factor corresponding to that region. The PWM duty cycle correction factor is used to adjust the PWM duty cycle upwards. The adjusted brightness values ​​of each low-grayscale brightness distortion region are obtained and compared with the target brightness value. If the adjusted brightness value of a low-grayscale brightness distortion region equals the target brightness value, then the PWM duty cycle adjustment for that region is completed. If the adjusted brightness value of a low-grayscale brightness distortion region is less than the target brightness value, then the PWM duty cycle adjustment for that region continues, and that region is marked... The iterative execution region is denoted as the iterative execution region, thus obtaining each iterative execution region. The brightness value after two consecutive PWM duty cycle iterations in each iterative execution region is obtained, and the degree of difference is analyzed to obtain the degree of brightness difference between adjacent iterations in each iterative execution region. A preset threshold for the degree of brightness difference in iterative adjustment is obtained from the database and compared with the degree of brightness difference between adjacent iterations in each iterative execution region to obtain the PWM duty cycle iterative adjustment judgment result. If the degree of brightness difference between adjacent iterations in an iterative execution region is below the threshold, the PWM duty cycle iterative adjustment judgment result for that iterative execution region is qualified. If the degree of brightness difference between adjacent iterations in an iterative execution region is greater than the threshold, the PWM duty cycle iterative adjustment judgment result for that iterative execution region is unqualified, and that iterative execution region is marked as an exposure adjustment execution region, thus obtaining each exposure adjustment execution region. In this embodiment, the PWM duty cycle is reduced and adjusted based on the PWM duty cycle correction factor corresponding to the low grayscale brightness distortion region. The specific method is as follows: In the formula, PZ1 represents the PWM duty cycle after the PWM duty cycle reduction adjustment, PZ0 represents the initial PWM duty cycle, and r1 represents the PWM duty cycle correction factor corresponding to the low grayscale brightness distortion region.

[0051] The PWM duty cycle is increased based on the PWM duty cycle correction factor corresponding to the low grayscale brightness distortion region. The specific method is as follows: In the formula, PZ1 represents the PWM duty cycle after the PWM duty cycle reduction adjustment, PZ0 represents the initial PWM duty cycle, and r1 represents the PWM duty cycle correction factor corresponding to the low grayscale brightness distortion region.

[0052] It should be noted that if the brightness value of a certain low grayscale brightness distortion area after PWM duty cycle iterative adjustment is less than the target brightness value, the PWM duty cycle adjustment will continue to be performed on that low grayscale brightness distortion area. This is because the current PWM duty cycle adjustment has not achieved the target brightness value for that low grayscale brightness distortion area, so iterative adjustment is needed to gradually bring the brightness value of that low grayscale brightness distortion area closer to the target brightness value.

[0053] By obtaining the brightness values ​​after two adjacent PWM duty cycle iterations in each iteration execution region and analyzing the degree of difference, the brightness difference value between adjacent iterations in each iteration execution region is obtained. This is because the brightness change value adjusted by only PWM duty cycle iteration is limited. If the brightness difference value between adjacent iterations in the iteration execution region is below the threshold of brightness difference, it means that the brightness value has reached the best effect by adjusting the PWM duty cycle. If the obtained brightness value is still less than the target brightness value, the exposure time needs to be adjusted to achieve the brightness value adjustment.

[0054] In the exposure adjustment execution area where brightness distortion still exists after PWM duty cycle adjustment, the light energy can be further finely controlled by introducing exposure duration adjustment. This is because the exposure duration directly determines the effective light emission duration of each frame within the visual perception time. Therefore, with a fixed PWM duty cycle, the light flux output per unit time can be effectively adjusted by appropriately extending or shortening the exposure duration, thereby increasing or decreasing the brightness. Compared to PWM adjustment, which only controls the duty cycle, exposure duration adjustment provides another means of controlling brightness from the time dimension, which can compensate for the brightness distortion problem caused by the limited accuracy of PWM adjustment in the low grayscale region.

[0055] Further, the exposure duration is adjusted as follows: The actual brightness value of each exposure adjustment execution area after PWM duty cycle adjustment is obtained and marked as the second brightness value of each exposure adjustment execution area; the actual brightness value of each exposure adjustment execution area before PWM duty cycle adjustment is obtained and marked as the first brightness value of each exposure adjustment execution area; the difference between the second brightness value and the target brightness of each exposure adjustment execution area is analyzed to obtain the first brightness difference value of each exposure adjustment execution area; the first brightness difference value of each exposure adjustment execution area is matched with the database to obtain the first exposure adjustment coefficient of each exposure adjustment execution area; the difference between the first brightness value and the second brightness value of each exposure adjustment execution area is analyzed to obtain the second brightness difference value of each exposure adjustment execution area; the second brightness difference value of each exposure adjustment execution area is matched with the database to obtain the second exposure adjustment coefficient of each exposure adjustment execution area; the exposure duration is adjusted for each exposure adjustment execution area based on the first and second exposure adjustment coefficients.

[0056] In this embodiment, as Figure 3 As shown, Figure 3 This application provides a flowchart of an exposure duration adjustment method for a low-latency Mini LED backlight control. The process involves obtaining the PWM duty cycle iterative adjustment judgment result. If the PWM duty cycle iterative adjustment judgment result is unqualified, exposure duration adjustment is performed. The method obtains the second brightness value, the first brightness value, and the target brightness value for each exposure adjustment execution area. Based on the analysis of the second brightness value and the target brightness of each exposure adjustment execution area, the method obtains the first brightness difference value for each exposure adjustment execution area. Based on the first brightness difference value of each exposure adjustment execution area, the method matches it with a database to obtain the first exposure adjustment coefficient for each exposure adjustment execution area. Based on the analysis of the first brightness value and the second brightness value of each exposure adjustment execution area, the method obtains the second brightness difference value for each exposure adjustment execution area. Based on the second brightness difference value, the method obtains the second exposure adjustment coefficient for each exposure adjustment execution area. Finally, the exposure duration is adjusted based on the first and second exposure adjustment coefficients of each exposure adjustment execution area, thus completing the exposure duration adjustment.

[0057] For each exposure adjustment execution area, the brightness difference before and after PWM adjustment is analyzed to calculate the first and second exposure adjustment coefficients. The exposure time is then adjusted accordingly, making the brightness output value of that area closer to the target brightness value. This process not only improves the accuracy of low grayscale brightness control but also effectively shortens the iteration convergence time, reduces overall control latency, and enhances the performance stability and visual consistency of the Mini LED backlight in low-brightness areas.

[0058] Based on the difference between the second brightness value and the target brightness of each exposure adjustment execution area, the first brightness difference value of each exposure adjustment execution area is obtained. The specific method is as follows: ;Formula CD j LT represents the first brightness difference value of the j-th exposure adjustment execution area. j This represents the second brightness value of the j-th exposure adjustment execution area, where HD represents the target brightness value, and j represents the number of the exposure adjustment execution area, j=1,2,...,j max ,j max This indicates the total number of areas where the exposure adjustment was implemented.

[0059] The first brightness difference value of each exposure adjustment execution area is matched with the database to obtain the first exposure adjustment coefficient for each exposure adjustment execution area. Specifically, the following method is used: The database is used to obtain a preset historical first brightness difference benchmark value, the exposure adjustment benchmark coefficient corresponding to the historical first brightness difference benchmark value, the historical first brightness difference gradient, and the brightness adjustment amplification coefficient corresponding to a single-level first brightness difference gradient. A difference is calculated between the first brightness difference value of the exposure adjustment execution area and the preset historical first brightness difference benchmark value in the database to obtain the first brightness difference difference value (the historical first brightness difference benchmark value is less than the first brightness difference value of the exposure adjustment execution area). A multiplier analysis is performed between the first brightness difference difference value and the preset historical first brightness difference benchmark value in the database (dividing the first brightness difference difference value by the historical first brightness difference benchmark value) to obtain the first brightness difference multiplier. Multiplying the first brightness difference multiplier by the brightness adjustment amplification coefficient corresponding to a single-level first brightness difference gradient yields the brightness adjustment amplification reference coefficient. Adding the brightness adjustment amplification reference coefficient to the exposure adjustment benchmark coefficient corresponding to the historical first brightness difference benchmark value yields the first exposure adjustment coefficient. Thus, the first exposure adjustment coefficient for each exposure adjustment execution area is obtained. Among them, the single-level first brightness difference gradient refers to the difference between the minimum values ​​of two adjacent first brightness difference gradient intervals.

[0060] Based on the difference between the first and second brightness values ​​of each exposure adjustment execution area, the difference value of the second brightness of each exposure adjustment execution area is obtained. The specific method is as follows: In the formula, CT j LT represents the second brightness difference value of the j-th exposure adjustment execution area. j L0 represents the second brightness value of the j-th exposure adjustment execution area. j This represents the first brightness value of the j-th exposure adjustment execution area.

[0061] The second brightness difference value of each exposure adjustment execution area is matched with the database to obtain the second exposure adjustment coefficient for each area. Specifically, the following method is used: The database is used to obtain a preset historical second brightness difference benchmark value, the corresponding exposure adjustment benchmark coefficient, the historical second brightness difference gradient, and the brightness adjustment amplification coefficient corresponding to a single-level second brightness difference gradient. The difference between the second brightness difference value of the exposure adjustment execution area and the preset historical second brightness difference benchmark value in the database is processed to obtain the second brightness difference difference (the historical second brightness difference benchmark value is less than the second brightness difference value of the exposure adjustment execution area). A multiplier analysis is then performed between the second brightness difference difference and the preset historical second brightness difference benchmark value in the database (dividing the second brightness difference difference by the historical second brightness difference benchmark value) to obtain the second brightness difference multiplier. Multiplying the second brightness difference multiplier by the brightness adjustment amplification coefficient corresponding to a single-level second brightness difference gradient yields the brightness adjustment amplification reference coefficient. Finally, adding the brightness adjustment amplification reference coefficient to the exposure adjustment benchmark coefficient corresponding to the historical second brightness difference benchmark value yields the second exposure adjustment coefficient. This analysis yields the second exposure adjustment coefficient for each exposure adjustment execution area. Among them, the single-level second brightness difference gradient refers to the difference between the minimum values ​​of two adjacent second brightness difference gradient intervals.

[0062] Based on the first and second exposure adjustment coefficients for each exposure adjustment region, the exposure duration is adjusted for each region. If the exposure adjustment region is a bright, distorted area, the adjustment method is to reduce the exposure duration for that region. Specifically: In the formula, B G1 B represents the adjusted exposure time. G0 Indicates the exposure time before adjustment, r b1 This indicates the first factor for exposure adjustment, r. b2 This represents the second exposure adjustment factor. If the area to be adjusted for exposure is a dark and distorted region, the adjustment method is to increase the exposure time in that area, specifically: In the formula, B G1 B represents the adjusted exposure time. G0 Indicates the exposure time before adjustment, r b1 This indicates the first factor for exposure adjustment, r. b2 This indicates the second factor for exposure adjustment.

[0063] Furthermore, the halo determination result is obtained by the following method: obtaining the adjacent brightness difference value of each adjacent low grayscale control area after distortion improvement and adjustment; obtaining the preset adjacent brightness difference threshold in the database and comparing it with the adjacent brightness difference value of each adjacent low grayscale control area to obtain the halo determination result. If the adjacent brightness difference value of a certain adjacent low grayscale control area is above the adjacent brightness difference threshold, the halo determination result is abnormal; otherwise, the halo determination result is normal.

[0064] In this embodiment, it should be noted that the brightness difference between adjacent low grayscale control areas after distortion improvement refers to the actual light output intensity (unit: cd / m²) displayed by the low grayscale control area, not the pixel grayscale or signal intensity. Therefore, the brightness difference between adjacent low grayscale control areas after distortion improvement is the difference between the adjacent brightness (actual light output intensity) of each adjacent low grayscale control area. The brightness difference between adjacent low grayscale control areas after distortion improvement can be obtained by capturing the entire Mini LED panel or a designated area with a brightness camera (also known as a brightness imaging colorimeter).

[0065] Further, halo improvement processing is performed. The specific method is as follows: Based on the adjacent brightness differences of each adjacent low-grayscale control area, the database is matched to obtain the first brightness adjustment influencing factor for each adjacent low-grayscale control area; the adjacent brightness differences of the adjacent low-grayscale control areas before distortion improvement are obtained and marked as the first brightness difference; the adjacent brightness differences of the adjacent low-grayscale control areas after distortion improvement are obtained and marked as the second brightness difference; the degree of difference is analyzed based on the first and second brightness differences to obtain the distortion adjustment brightness difference value; the distortion adjustment brightness difference value is matched with the database to obtain the second brightness adjustment influencing factor. From this, the brightness difference of each adjacent low-grayscale control area is statistically analyzed. The system employs several methods: 1) adjusting the brightness of the low-grayscale controlled light region using a second influencing factor; 2) obtaining the halo adjustment influence parameters of each adjacent low-grayscale controlled light region and analyzing them to obtain the halo adjustment influence value of each adjacent low-grayscale controlled light region; 3) matching the halo adjustment influence value of each adjacent low-grayscale controlled light region with the database to obtain the edge blending width of each adjacent low-grayscale controlled light region; 4) correcting the edge blending width of each adjacent low-grayscale controlled light region based on the brightness adjustment first and second influencing factors to obtain the actual edge blending width of each adjacent low-grayscale controlled light region; and 5) performing halo improvement processing on each adjacent low-grayscale controlled light region based on the actual edge blending width of each adjacent low-grayscale controlled light region.

[0066] In this embodiment, the brightness adjustment first influencing factor of each adjacent low grayscale control region is obtained by matching the adjacent brightness difference of each adjacent low grayscale control region with the database. The specific method is as follows: obtain the preset adjacent brightness difference threshold, the brightness adjustment benchmark correction factor corresponding to the adjacent brightness difference threshold, the single-level adjacent brightness difference gradient, and the brightness adjustment amplification correction coefficient corresponding to the single-level adjacent brightness difference gradient in the database. Subtract the preset adjacent brightness difference threshold in the database from the adjacent brightness difference (the adjacent brightness difference threshold is a very small value, which is less than the adjacent brightness difference) to obtain the adjacent brightness threshold difference. Perform a multiple analysis on the adjacent brightness threshold difference and the single-level adjacent brightness difference gradient (specifically, divide the adjacent brightness threshold difference by the single-level adjacent brightness difference gradient) to obtain the adjacent brightness threshold difference multiple. Multiply the adjacent brightness threshold difference multiple by the brightness adjustment amplification correction coefficient corresponding to the single-level adjacent brightness difference gradient and add it to the brightness adjustment benchmark correction factor corresponding to the adjacent brightness difference threshold to obtain the brightness adjustment first influencing factor. Thus, the brightness adjustment first influencing factor of each adjacent low grayscale control region is obtained. The single-level adjacent brightness difference gradient refers to the difference between the minimum values ​​of two adjacent brightness difference gradient intervals.

[0067] The degree of difference is analyzed based on the first brightness difference and the second brightness difference to obtain the value of the difference in brightness for distortion adjustment. The specific method is as follows: subtract the first brightness difference from the second brightness difference and take the absolute value to obtain the brightness difference adjustment value. Divide the brightness difference adjustment value by the first brightness difference to obtain the value of the difference in brightness for distortion adjustment.

[0068] The second influencing factor for brightness adjustment is obtained by matching the distortion adjustment brightness difference value with a database. Specifically, the method involves: acquiring a preset distortion adjustment brightness difference gradient and a single-gradient distortion adjustment brightness influence factor from the database; performing a factorial analysis (dividing the distortion adjustment brightness difference value by the preset gradient) to obtain the distortion adjustment brightness difference factor; and multiplying this factorial by the single-gradient distortion adjustment brightness influence factor to obtain the second influencing factor for brightness adjustment. The distortion adjustment brightness difference gradient refers to the difference between the minimum values ​​of two adjacent distortion adjustment brightness difference intervals.

[0069] The edge blending width of each adjacent low-grayscale control region is obtained by matching the halo adjustment influence value of each region with the database. Specifically, the method involves obtaining the preset halo adjustment influence baseline value, the edge blending width corresponding to the baseline value, the halo adjustment influence gradient, and the increase in edge blending width corresponding to a single halo adjustment influence gradient from the database. A difference is calculated between the halo adjustment influence value and the preset baseline value (where the halo adjustment influence value is greater than the baseline value, and the baseline value is a preset minimum value) to obtain the halo adjustment influence difference. This difference is then divided by the halo adjustment influence gradient to obtain the halo adjustment influence multiple. Finally, the edge blending width is obtained by multiplying the halo adjustment influence multiple by the increase in edge blending width corresponding to a single halo adjustment influence gradient and adding this product to the edge blending width corresponding to the baseline value. This gives the edge blending width of each adjacent low-grayscale control region. It should be noted that the halo adjustment influence gradient refers to the difference between the minimum values ​​of two adjacent halo adjustment influence gradient intervals.

[0070] The actual edge blending width of each adjacent low grayscale light control region is obtained using the following method: In the formula, B ka This represents the actual edge blending width of the k-th adjacent low-grayscale light-controlling region, where k represents the number of the adjacent low-grayscale light-controlling region, k=1,2,...,k max ,k max B represents the total number of adjacent low-grayscale light-controlling regions. kb Y represents the edge blending width of the k-th adjacent low grayscale control region. k1 Y represents the first influencing factor for brightness adjustment of the k-th adjacent low grayscale control region. k2 This represents the second influencing factor for adjusting the brightness of the k-th adjacent low grayscale control region.

[0071] The halo improvement process is performed on each adjacent low grayscale light control region based on the actual edge blending width of each adjacent low grayscale light control region. The specific method is as follows: obtain the brightness difference between adjacent grayscale light control regions, divide the brightness difference of the grayscale light control region by the actual edge blending width to obtain the brightness change value corresponding to the unit actual edge blending width, and then perform progressive processing on the brightness value of the adjacent low grayscale light control region based on the brightness change value corresponding to the unit actual edge blending width. The brightness change value corresponding to the unit actual edge blending width is the progressive change amount. For example, if the brightness values ​​of the adjacent low grayscale light control regions where the unit actual edge blending width is located are 4 nits and 6 nits respectively, and the actual edge blending width is 1 pixel width, then the brightness change amount corresponding to the unit width is (6 - 4) / 1 = 2 nits. At this time, it is necessary to continuously transition the brightness between 4 and 6 nits to achieve a smooth brightness transition.

[0072] By comprehensively analyzing and finely matching the edge blending width by considering changes in brightness difference (the first brightness difference and the second brightness difference), brightness adjustment influencing factors, and halo adjustment influencing values, adaptive edge blending can be achieved that varies depending on the region and the degree of distortion. This helps to effectively avoid problems such as image blurring due to excessively large blending widths and halo residue due to excessively small blending widths. Thus, while controlling the halo intensity, it ensures the image edge clarity and the naturalness of brightness transitions between regions, improving the consistency and accuracy of overall image quality.

[0073] Furthermore, the halo adjustment influence value of each adjacent low grayscale light control region is obtained. The specific method is as follows: obtain the halo adjustment influence parameters of each adjacent low grayscale light control region. The halo adjustment influence parameters include grayscale difference, PWM duty cycle difference, edge emission overlap width, and halo peak brightness; obtain the preset halo adjustment influence benchmark set in the database and compare it with the halo adjustment influence parameters of each adjacent low grayscale light control region to obtain the comparison analysis results; based on the comparison analysis results, introduce the corresponding weighting factor for coupling processing to obtain the halo adjustment influence value of each adjacent low grayscale light control region; the halo adjustment influence benchmark set includes grayscale difference benchmark value, PWM duty cycle difference benchmark value, edge emission overlap width benchmark value, and halo peak brightness benchmark value.

[0074] In this embodiment, it should be noted that, as Figure 8 As shown, Figure 8 This is a comparative schematic diagram of the correction and adjustment effect of the low grayscale distortion area in a low-latency Mini LED backlight control system provided in an embodiment of this application. From this, we can obtain the compensation success rate after the distortion area is compensated and adjusted, the specific compensation result, the number of distortion areas, and the details of the compensation effect of each distortion area, such as the brightness before and after adjustment, and whether the compensation is successful.

[0075] All parameters affecting halo adjustment are actual displayed values. Grayscale difference refers to the absolute value of the difference between the actual grayscale levels of two adjacent low-grayscale control areas, reflecting the difference in grayscale level between the two areas in the target brightness output. Grayscale value is the basic unit for brightness gradation in backlight control. A larger grayscale difference indicates a more obvious brightness contrast between the two areas, easily forming visual breaks at the area edges and inducing halo phenomena. PWM duty cycle difference refers to the difference between the duty cycles of the PWM signals corresponding to two adjacent low-grayscale control areas, i.e., the difference in the proportion of LED conduction time between the two areas per unit cycle. Edge emission overlap width refers to the overlap range of the LED backlight emission areas at the boundary of adjacent control areas. Halo peak brightness refers to the maximum value of the brightness peak in the transition area at the boundary of adjacent control areas.

[0076] The halo adjustment influence value of each adjacent low grayscale light control region is obtained by the following method:

[0077] ;

[0078] In the formula, GT k This represents the halo adjustment effect value of the k-th adjacent low-grayscale light-controlling region, where k represents the number of the adjacent low-grayscale light-controlling region, k=1,2,...,k max ,k max GH represents the total number of adjacent low-grayscale light-controlling regions. k This represents the grayscale difference between the k-th adjacent low-grayscale control regions, where TH represents the grayscale difference reference value, and GZ represents the grayscale difference reference value. k TZ represents the PWM duty cycle difference between the k-th adjacent low grayscale control regions, and GB represents the baseline value of the PWM duty cycle difference. k GF represents the edge emission overlap width of the k-th adjacent low grayscale control region, TB represents the baseline value of the edge emission overlap width, and GF represents the baseline value of the edge emission overlap width. k τ1 represents the peak brightness of the halo in the kth adjacent low grayscale light control region, TF represents the reference value of the peak brightness of the halo, τ1 represents the grayscale difference weighting factor, τ2 represents the PWM duty cycle difference weighting factor, τ3 represents the edge emission overlap width weighting factor, and τ4 represents the peak brightness of the halo weighting factor.

[0079] The grayscale difference weighting factor, PWM duty cycle difference weighting factor, edge emission overlap width weighting factor, and halo peak brightness weighting factor can be obtained from a database. For example, the grayscale difference weighting factor can be obtained by analyzing the historical grayscale difference set stored in the database. The difference between each historical grayscale difference in the historical grayscale difference set is processed to obtain the historical grayscale difference value. A preset grayscale difference value threshold range in the database is obtained and compared with each historical grayscale difference value. If a historical grayscale difference value falls within the grayscale difference value threshold range, the corresponding historical grayscale difference value is obtained and marked as the historical control grayscale difference, thus obtaining each historical control grayscale difference. The extreme values ​​of each historical control grayscale difference are removed (maximum and minimum values ​​are removed), and the standard deviation is taken to obtain the standard deviation of the historical control grayscale difference. The system retrieves preset historical reference grayscale difference weighting factors, historical control grayscale difference standard deviation benchmarks, historical grayscale difference control standard deviation difference gradients, and single-level adjustment amounts of the grayscale difference weighting factors from the database. It then performs difference processing between the historical control grayscale difference standard deviations and the historical control grayscale difference benchmark values ​​to obtain the historical control grayscale difference standard deviation difference value. Finally, it performs a fold analysis (dividing the historical control grayscale difference standard deviation difference value by the historical grayscale difference control standard deviation difference gradient value) to obtain the historical grayscale difference control standard deviation difference gradient fold. The gray-scale difference weighting factor is obtained by multiplying the gradient multiple of the historical gray-scale difference standard deviation difference by the single-level adjustment of the gray-scale difference weighting factor. Based on the comparison between the historical gray-scale difference standard deviation and the historical gray-scale difference standard deviation benchmark value, if the historical gray-scale difference standard deviation is greater than the historical gray-scale difference benchmark value, the historical reference gray-scale difference weighting factor is added to the gray-scale difference weighting factor to obtain the gray-scale difference weighting factor; otherwise, the historical reference gray-scale difference weighting factor is subtracted from the gray-scale difference weighting factor to obtain the gray-scale difference weighting factor.

[0080] The single-level adjustment amount of the grayscale difference weighting factor refers to the adjustment amount required for each increase in the historical grayscale difference standard deviation gradient. The historical grayscale difference standard deviation gradient refers to the difference between the minimum values ​​of two adjacent grayscale difference gradient intervals. Other weighting factors, such as the PWM duty cycle difference weighting factor, the edge emission overlap width weighting factor, and the halo peak brightness weighting factor, are obtained in the same way as the grayscale difference weighting factor.

[0081] By analyzing the parameters affecting halo adjustment, including grayscale difference, PWM duty cycle difference, edge emission overlap width, and halo peak brightness, the halo adjustment influence values ​​of each adjacent low grayscale control region were obtained. This analysis takes into account the interrelationships between these parameters. For example, grayscale difference and PWM duty cycle difference are directly related. Grayscale difference reflects the difference in target brightness levels between regions, while PWM duty cycle is the core parameter for controlling grayscale output. A larger grayscale difference indicates that a larger PWM duty cycle difference is needed to achieve the corresponding brightness; therefore, the two are positively correlated. A larger PWM duty cycle difference combined with a smaller overlap width will result in more drastic brightness changes, forming a strong boundary contrast and amplifying the halo phenomenon. Conversely, an appropriate overlap width can alleviate the brightness discontinuity caused by PWM differences. The halo peak brightness is jointly affected by the grayscale difference and the PWM duty cycle adjustment results. In the case of insufficient edge blending, a larger grayscale or PWM difference will lead to a concentration of local peak brightness, resulting in a more significant halo effect.

[0082] like Figure 4 The diagram shown is a structural schematic of a low-latency Mini LED backlight control system provided in an embodiment of this application. The low-latency Mini LED backlight control system provided in this embodiment includes: a low grayscale brightness area determination module, a low grayscale brightness distortion area screening module, a distortion improvement adjustment module, and a halo improvement processing module; wherein, the low grayscale brightness area determination module is used for Mini... The LED central processing unit retrieves the current image frame and divides the light control area to obtain each light control area. Each light control area is then filtered for brightness to obtain low grayscale brightness areas. A low grayscale brightness distortion area filtering module obtains the actual brightness value of each low grayscale brightness area and compares it with the target brightness value to obtain the low grayscale brightness distortion judgment result and each low grayscale brightness distortion area. A distortion improvement and adjustment module obtains the brightness distortion influence parameters of each low grayscale brightness distortion area, analyzes and obtains the PWM duty cycle correction factor for each low grayscale brightness distortion area, and performs iterative adjustment of the PWM duty cycle to obtain the PWM duty cycle iterative adjustment judgment result. If the PWM duty cycle iterative adjustment judgment result is qualified, the processing is completed; otherwise, the exposure time is adjusted. A halo improvement processing module obtains the brightness difference between adjacent low grayscale brightness distortion areas after distortion improvement and analysis to obtain the halo judgment result. If the halo judgment result is qualified, halo improvement processing is not performed; otherwise, halo improvement processing is performed. Distortion improvement and adjustment includes PWM duty cycle iterative adjustment and exposure time adjustment.

[0083] In summary, this embodiment achieves accurate identification and graded adjustment of low grayscale brightness distortion and halo problems by dividing the light control area based on image frames, identifying low grayscale brightness areas, determining brightness distortion, and analyzing halo. This enables accurate restoration of the brightness distortion and halo effects of Mini LED backlights in low grayscale scenarios, effectively solving the problem of low grayscale brightness distortion and halo caused by abrupt changes in partition edges due to insufficient control precision in the prior art.

[0084] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0085] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0086] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0087] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0088] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0089] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A low-latency Mini LED backlight control method, characterized in that, Includes the following steps: The Mini LED central processing unit retrieves the current image frame, divides the light control area, obtains each light control area, and filters the brightness of each light control area to obtain each low grayscale brightness area. The actual brightness value of each low grayscale brightness region is obtained and compared with the target brightness value to obtain the low grayscale brightness distortion judgment result and each low grayscale brightness distortion region. Obtain the brightness distortion influence parameters of each low grayscale brightness distortion region, analyze and obtain the PWM duty cycle correction factor of each low grayscale brightness distortion region, and then perform PWM duty cycle iterative adjustment to obtain the PWM duty cycle iterative adjustment judgment result. If the PWM duty cycle iterative adjustment judgment result is qualified, the processing is completed; otherwise, the exposure time adjustment is performed. After distortion correction, obtain the brightness difference between adjacent low grayscale brightness distortion areas and analyze the halo judgment result. If the halo judgment result is qualified, halo correction is not performed; otherwise, halo correction is performed. The distortion improvement adjustment includes iterative adjustment of PWM duty cycle and exposure duration adjustment; The exposure duration is the effective illumination duration for each frame of the image.

2. The low-latency Mini LED backlight control method as described in claim 1, characterized in that: The specific method for obtaining each low grayscale brightness region is as follows: Obtain the target brightness value of each light-controlled area; Obtain the preset minimum controllable brightness threshold from the database and compare it with the target brightness value of each light control area. If the target brightness value of a certain light control area is less than the minimum controllable brightness threshold, then mark the light control area as a low grayscale brightness area. In this way, the low grayscale brightness areas are statistically obtained.

3. The low-latency Mini LED backlight control method as described in claim 1, characterized in that: The specific method for obtaining the low grayscale brightness distortion determination result and each low grayscale brightness distortion region is as follows: The actual brightness value of each low grayscale brightness area is obtained and the absolute difference is processed with the target brightness value to obtain the target brightness difference of each low grayscale brightness area. The preset brightness difference threshold in the database is obtained and compared with the target brightness difference value of each low grayscale brightness area to obtain the low grayscale brightness distortion judgment result. If the target brightness difference value of a certain low grayscale brightness area is less than the brightness difference threshold, the low grayscale brightness distortion judgment result of the low grayscale brightness area is normal; otherwise, the low grayscale brightness distortion judgment result of the low grayscale brightness area is abnormal. The low grayscale brightness areas with abnormal low grayscale brightness distortion judgment results are marked as low grayscale brightness distortion areas. Thus, each low grayscale brightness distortion area is statistically obtained. The brightness values ​​of each low grayscale brightness distortion region are compared with the target brightness value. Low grayscale brightness distortion regions with brightness values ​​greater than the target brightness value are marked as overly bright distortion regions, and low grayscale brightness distortion regions with brightness values ​​less than the target brightness value are marked as overly dark distortion regions.

4. The low-latency Mini LED backlight control method as described in claim 1, characterized in that: The PWM duty cycle correction factor for each low grayscale brightness distortion region is specifically described using the following method: Obtain the brightness distortion influence parameters of each low grayscale brightness distortion region, including the starting drive current, minimum current step size, system refresh frequency, and grayscale adjustment step size. Obtain the preset baseline set of brightness distortion influence in the database and compare it with the brightness distortion influence parameters of each low grayscale brightness distortion region to obtain the comparison analysis results. Based on the comparison analysis results, introduce the corresponding weighting factor for coupling processing to obtain the brightness distortion influence value of each low grayscale brightness distortion region. Based on the brightness distortion influence value of each low grayscale brightness distortion region and the database, the PWM duty cycle correction factor of each low grayscale brightness distortion region is obtained. The baseline set for brightness distortion effects includes the baseline value of the starting drive current, the baseline value of the minimum current step size, the baseline value of the system refresh frequency, and the baseline value of the grayscale adjustment step size.

5. The low-latency Mini LED backlight control method as described in claim 1, characterized in that: The method for performing iterative adjustment of the PWM duty cycle to obtain the PWM duty cycle iterative adjustment determination result is as follows: The PWM duty cycle of each low grayscale brightness distortion region is adjusted based on the PWM duty cycle correction factor of each low grayscale brightness distortion region. If a low grayscale brightness distortion region is a bright distortion region, the PWM duty cycle is reduced based on the PWM duty cycle correction factor corresponding to that low grayscale brightness distortion region. If a low grayscale brightness distortion region is a dark distortion region, the PWM duty cycle is increased based on the PWM duty cycle correction factor corresponding to that low grayscale brightness distortion region. The brightness value after PWM duty cycle adjustment in each low grayscale brightness distortion region is obtained and compared with the target brightness value. If the brightness value after PWM duty cycle adjustment in a certain low grayscale brightness distortion region is equal to the target brightness value, then the PWM duty cycle adjustment of that low grayscale brightness distortion region is completed. If the brightness value after PWM duty cycle adjustment in a certain low grayscale brightness distortion region is less than the target brightness value, then the PWM duty cycle adjustment of that low grayscale brightness distortion region continues, and that region is marked as the iterative execution region, thus obtaining each iterative execution region. Obtain the brightness values ​​after two adjacent PWM duty cycle iterations in each iteration execution region, and perform a difference analysis to obtain the brightness difference values ​​between adjacent iterations in each iteration execution region. The preset threshold for the degree of brightness difference in iterative adjustment is obtained from the database and compared with the degree of brightness difference between adjacent iterative adjustment regions in each iterative execution region to obtain the PWM duty cycle iterative adjustment judgment result. If the degree of brightness difference between adjacent iterative adjustment regions in a certain iterative execution region is below the threshold, the PWM duty cycle iterative adjustment judgment result for that iterative execution region is qualified. If the degree of brightness difference between adjacent iterative adjustment regions in a certain iterative execution region is greater than the threshold, the PWM duty cycle iterative adjustment judgment result for that iterative execution region is unqualified, and that iterative execution region is marked as the exposure adjustment execution region, thus obtaining each exposure adjustment execution region.

6. The low-latency Mini LED backlight control method as described in claim 1, characterized in that: The specific method for adjusting the exposure duration is as follows: Obtain the actual brightness value of each exposure adjustment execution area after PWM duty cycle adjustment, and mark it as the second brightness value of each exposure adjustment execution area; Obtain the actual brightness value of each exposure adjustment execution area before PWM duty cycle adjustment, and mark it as the first brightness value of each exposure adjustment execution area; Based on the difference between the second brightness value and the target brightness of each exposure adjustment execution area, the first brightness difference value of each exposure adjustment execution area is obtained. Based on the first brightness difference value of each exposure adjustment execution area, the database is matched to obtain the first exposure adjustment coefficient of each exposure adjustment execution area. Based on the difference between the first brightness value and the second brightness value of each exposure adjustment execution area, the second brightness difference value of each exposure adjustment execution area is obtained. Based on the second brightness difference value of each exposure adjustment execution area, the database is matched to obtain the second exposure adjustment coefficient of each exposure adjustment execution area. The exposure duration is adjusted for each exposure adjustment execution area based on the first exposure adjustment coefficient and the second exposure adjustment coefficient.

7. The low-latency Mini LED backlight control method as described in claim 1, characterized in that: The specific method for obtaining the halo determination result is as follows: Obtain the adjacent brightness difference values ​​of each adjacent low grayscale light control area after distortion improvement adjustment; Obtain the preset adjacent brightness difference threshold from the database and compare it with the adjacent brightness difference value of each adjacent low grayscale control area to obtain the halo judgment result. If the adjacent brightness difference value of an adjacent low grayscale control area is above the adjacent brightness difference threshold, the halo judgment result is abnormal; otherwise, the halo judgment result is normal.

8. The low-latency Mini LED backlight control method as described in claim 7, characterized in that: The specific method for performing halo improvement processing is as follows: Based on the adjacent brightness difference of each adjacent low grayscale control area, the first influencing factor of brightness adjustment of each adjacent low grayscale control area is obtained by matching with the database. Obtain the adjacent brightness difference values ​​of adjacent low grayscale light control areas before distortion improvement adjustment, and mark them as the first brightness difference value; After distortion improvement adjustment, obtain the adjacent brightness difference values ​​of adjacent low grayscale light control areas and mark them as the second brightness difference value; Based on the first brightness difference and the second brightness difference, the degree of difference is analyzed to obtain the value of the difference in brightness adjustment due to distortion. Based on the value of the difference in brightness adjustment due to distortion, it is matched with the database to obtain the second influence factor of brightness adjustment. Thus, the second influence factor of brightness adjustment for each adjacent low grayscale control area is statistically obtained. Obtain the halo adjustment influence parameters of each adjacent low grayscale light control region, and analyze them to obtain the halo adjustment influence value of each adjacent low grayscale light control region; The edge blending width of each adjacent low grayscale light control region is obtained by matching the halo adjustment influence value of each adjacent low grayscale light control region with the database. Based on the first and second influence factors of brightness adjustment of each adjacent low grayscale control area, the edge blending width of each adjacent low grayscale control area is corrected to obtain the actual edge blending width of each adjacent low grayscale control area. The halo effect of each adjacent low grayscale light control region is improved based on the actual width of the edge blending of each adjacent low grayscale light control region.

9. The low-latency Mini LED backlight control method as described in claim 8, characterized in that: The method for obtaining the halo adjustment influence value of each adjacent low grayscale light control region is as follows: Obtain the halo adjustment influence parameters of each adjacent low grayscale light control region. The halo adjustment influence parameters include grayscale difference, PWM duty cycle difference, edge emission overlap width and halo peak brightness. Obtain the preset halo adjustment influence benchmark set in the database and compare it with the halo adjustment influence parameters of each adjacent low grayscale control area to obtain the comparison analysis results. Based on the comparison analysis results, introduce the corresponding weighting factor for coupling processing to obtain the halo adjustment influence value of each adjacent low grayscale control area. The halo adjustment influence reference set includes grayscale difference reference value, PWM duty cycle difference reference value, edge emission overlap width reference value, and halo peak brightness reference value.

10. A low-latency Mini LED backlight control system, employing the low-latency Mini LED backlight control method as described in any one of claims 1-9, characterized in that, include: Low grayscale brightness area determination module, low grayscale brightness distortion area screening module, distortion improvement and adjustment module, and halo improvement processing module; The low grayscale brightness area determination module is used by the Mini LED central processing unit to retrieve the current image frame, divide the light control area, obtain each light control area, and filter the brightness of each light control area to obtain each low grayscale brightness area. The low grayscale brightness distortion region filtering module is used to obtain the actual brightness value of each low grayscale brightness region and compare it with the target brightness value to obtain the low grayscale brightness distortion judgment result and each low grayscale brightness distortion region. The distortion improvement and adjustment module is used to obtain the brightness distortion influence parameters of each low grayscale brightness distortion region, analyze and obtain the PWM duty cycle correction factor of each low grayscale brightness distortion region, and then perform PWM duty cycle iterative adjustment to obtain the PWM duty cycle iterative adjustment judgment result. If the PWM duty cycle iterative adjustment judgment result is qualified, the processing is completed; otherwise, the exposure time adjustment is performed. The halo improvement processing module is used to obtain the brightness difference between adjacent low grayscale brightness distortion areas after distortion improvement and adjustment, and analyze the halo judgment result. If the halo judgment result is qualified, halo improvement processing is not performed; otherwise, halo improvement processing is performed. The distortion improvement adjustment includes iterative adjustment of PWM duty cycle and adjustment of exposure time.

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