Brightness compensation method and device of display panel, display equipment and storage medium

Abstract

The invention relates to a brightness compensation method and device of a display panel, display equipment and a storage medium. The method comprises the following steps: acquiring a to-be-displayed image and a gray-brightness curve corresponding to each pixel in the display panel; segmenting the gray-brightness curve corresponding to each pixel to obtain N curve segments of each pixel, and performing linear fitting on the N curve segments of each pixel to obtain N linear functions of each pixel, the N curve segments of each pixel corresponding to N gray intervals of each pixel, and N being an integer greater than 1; obtaining the position information of each pixel, and adjusting the slopes of the N linear functions of each pixel according to the position information of each pixel; and based on the N linear functions after slope adjustment of each pixel, compensating the gray level of each pixel in the to-be-displayed image to obtain a compensated image, and displaying the compensated image. Therefore, the uniformity of the brightness of the display panel is improved, and the display effect of the display panel is further improved.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a brightness compensation method, apparatus, display device, and storage medium for a display panel. Background Technology

[0002] Organic Light Emitting Display (OLED) is widely used as a display panel in mobile phones, televisions, augmented reality (AR) devices, and virtual reality (VR) devices due to its advantages such as self-illumination, high contrast, and fast response. However, OLEDs suffer from inherent defects such as static area aging (e.g., continuous high brightness emission in fixed areas like status bars and icons leads to accelerated degradation of organic materials) and uneven edge brightness (e.g., current transmission losses in the display cause edge pixels to have 15%-25% lower current than the center, forming a "dark edge"). These defects result in poor display quality and a tendency for uneven brightness. Figure 1 As shown, therefore, how to improve the uniformity of brightness of the display panel has become an urgent technical problem to be solved. Summary of the Invention

[0003] This application provides a brightness compensation method, apparatus, display device, and storage medium for a display panel to solve the problem of uneven brightness in existing display panels.

[0004] In a first aspect, embodiments of this application provide a brightness compensation method for a display panel, the method comprising:

[0005] The image to be displayed is obtained, as well as the grayscale-brightness curves corresponding to each pixel in the display panel, which is used to display the image to be displayed;

[0006] The gray-scale-brightness curve corresponding to each pixel is segmented to obtain N curve segments for each pixel. Then, the N curve segments for each pixel are linearly fitted to obtain N linear functions for each pixel. The N curve segments for each pixel correspond to the N gray-scale intervals of each pixel, and N is an integer greater than 1.

[0007] Obtain the position information of each pixel, and adjust the slope of N linear functions for each pixel based on the position information of each pixel;

[0008] Based on N linear functions adjusted by the slope of each pixel, the grayscale of each pixel in the image to be displayed is compensated to obtain a compensated image, and the compensated image is then displayed.

[0009] Optionally, the step of linearly fitting the N curve segments of each pixel to obtain N linear functions for each pixel includes:

[0010] The least squares method is used to perform linear fitting on N curve segments of each pixel to determine the fitting parameters of N curve segments of each pixel. The fitting parameters include a first parameter for characterizing the slope of N linear functions of each pixel and a second parameter for characterizing the intercept of N linear functions of each pixel.

[0011] Based on the first parameter and the second parameter, N linear functions for each pixel are obtained.

[0012] Optionally, the step of obtaining the position information of each pixel and adjusting the slope of the N linear functions of each pixel based on the position information of each pixel includes:

[0013] Obtain the position information of each pixel, and calculate the distance from each pixel to the center of the display panel based on the position information of each pixel;

[0014] Calculate the ratio of the distance to the diagonal length of the display panel;

[0015] Based on the ratio, the slopes of the N linear functions for each pixel are adjusted, wherein the adjustment amount of the slopes of the N linear functions for each pixel is positively correlated with the ratio.

[0016] Optionally, the slopes of the N linear functions for each pixel are adjusted according to the following formula:

[0017] a i ′=a i ·(1+k·dn(x,y));

[0018] Among them, a i ′ represents the slope of pixel (x,y) adjusted by i linear functions, a i The slope of pixel (x,y) before adjustment by the i linear functions is represented, k represents the preset coefficient, and dn(x,y) represents the ratio of the distance from pixel (x,y) to the center of the display panel to the length of the diagonal of the display panel.

[0019] Optionally, the step of compensating the grayscale of each pixel in the image to be displayed based on N linear functions adjusted for the slope of each pixel to obtain a compensated image includes:

[0020] Obtain the actual grayscale and target brightness of each pixel in the image to be displayed;

[0021] Based on the actual gray level of each pixel, a target linear function for each pixel is determined, wherein the gray level range corresponding to the target linear function includes the actual gray level of the corresponding pixel;

[0022] The grayscale value of each pixel after compensation is calculated using the target linear function and the target brightness of each pixel.

[0023] The actual gray level of each pixel is compensated according to the gray level of each pixel after compensation, to obtain the compensated image.

[0024] Optionally, the step of calculating the compensated grayscale of each pixel using the target linear function and the target brightness of each pixel includes:

[0025] Calculate the difference between the target brightness of the target pixel and the intercept of the target linear function of the target pixel, wherein the target pixel is any pixel in the display panel;

[0026] Calculate the ratio between the difference and the slope of the target linear function of the target pixel;

[0027] The ratio is determined as the grayscale value of the target pixel after compensation.

[0028] Optionally, the formula for calculating the grayscale of the target pixel after compensation is as follows:

[0029] G(x,y)=(Target_L-b j ) / a j ′;

[0030] Where G(x,y) represents the grayscale of the target pixel after compensation, Target_L represents the target brightness of the target pixel, and b j a represents the intercept of the target linear function of the target pixel. j ′ represents the slope of the target linear function of the target pixel.

[0031] Secondly, embodiments of this application also provide a brightness compensation device for a display panel, the device comprising:

[0032] An acquisition module is used to acquire an image to be displayed and the grayscale-brightness curves corresponding to each pixel in the display panel, wherein the display panel is used to display the image to be displayed;

[0033] The segmentation and fitting module is used to segment the gray-level-brightness curve corresponding to each pixel to obtain N curve segments for each pixel, and to perform linear fitting on the N curve segments for each pixel to obtain N linear functions for each pixel. Here, the N curve segments for each pixel correspond to the N gray-level intervals for each pixel, and N is an integer greater than 1.

[0034] The adjustment module is used to obtain the position information of each pixel and adjust the slope of N linear functions of each pixel according to the position information of each pixel;

[0035] The compensation module is used to compensate the grayscale of each pixel in the image to be displayed based on N linear functions adjusted by the slope of each pixel, to obtain a compensated image, and to display the compensated image.

[0036] Thirdly, embodiments of this application also provide a display device, the display device comprising: a display panel and the brightness compensation device of the display panel described in the second aspect;

[0037] The display panel and the brightness compensation device of the display panel are electrically connected.

[0038] Fourthly, embodiments of this application also provide a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the brightness compensation method for the display panel described in the first aspect.

[0039] Compared with the prior art, the technical solution provided in this application has the following advantages: The method provided in this application acquires an image to be displayed and grayscale-brightness curves corresponding to each pixel in a display panel, wherein the display panel is used to display the image to be displayed; the grayscale-brightness curves corresponding to each pixel are segmented to obtain N curve segments for each pixel, and the N curve segments for each pixel are linearly fitted to obtain N linear functions for each pixel, wherein the N curve segments for each pixel correspond to N grayscale intervals for each pixel, and N is an integer greater than 1; the position information of each pixel is acquired, and the slope of the N linear functions for each pixel is adjusted according to the position information of each pixel; based on the N linear functions after the slope adjustment of each pixel, the grayscale of each pixel in the image to be displayed is compensated to obtain a compensated image, and the compensated image is displayed. By using the above method, the grayscale-brightness curve corresponding to each pixel can be segmented and then linearly fitted to obtain N linear functions for each pixel. This results in the non-linear relationship of the grayscale-brightness curve for each pixel, effectively avoiding inaccurate compensation caused by uniform compensation for static and non-static pixels. Furthermore, the slope of the N linear functions for each pixel can be adaptively adjusted based on the position information of each pixel, further eliminating the problem of low brightness in edge pixels. This improves the uniformity of brightness of the display panel and thus enhances the display effect of the display panel. Attached Figure Description

[0040] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0043] Figure 1 This is a schematic diagram illustrating uneven brightness in a display panel in the prior art.

[0044] Figure 2 A schematic flowchart illustrating a brightness compensation method for a display panel provided in an embodiment of this application;

[0045] Figure 3 A schematic flowchart illustrating another brightness compensation method for a display panel provided in an embodiment of this application;

[0046] Figure 4 A schematic diagram of the structure of a brightness compensation device for a display panel provided in an embodiment of this application;

[0047] Figure 5 This is a schematic diagram of the structure of a display device provided in an embodiment of this application. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0049] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0050] See Figure 2 , Figure 2This is a schematic flowchart illustrating a brightness compensation method for a display panel provided in an embodiment of this application. Figure 2 As shown, the brightness compensation method for this display panel may include the following steps:

[0051] Step S201: Obtain the image to be displayed and the grayscale-brightness curves corresponding to each pixel in the display panel. The display panel is used to display the image to be displayed.

[0052] Specifically, the image to be displayed can be any frame of an image, such as a mobile phone interface or video footage. This image can be a color image or a grayscale image. If it is a color image, it needs to be converted to grayscale to obtain the grayscale value of each pixel. Taking an 8-bit display panel as an example, the grayscale range of each pixel in the image to be displayed is 0–255. The grayscale-brightness curve described above is used to characterize the trend of brightness change of each pixel as its grayscale value changes. In practical applications, this grayscale-brightness curve is usually non-linear. The grayscale-brightness curve of each pixel can be obtained by statistical analysis using a high-resolution luminance meter / camera. Specifically, the display panel can be controlled to sequentially display full-screen images of each grayscale level: for example, starting from grayscale G=0 (complete black), displaying G=0,1,2,...,255 frame by frame (pausing at each grayscale level for a period of time to ensure the camera captures stable brightness); then, using a high-resolution luminance meter / camera to capture each frame image, extracting the brightness value L of each pixel at that grayscale level (for example, when G=0, the brightness of pixel (x,y) is L0; when G=1, the brightness of pixel (x,y) is L1, and so on); finally, sorting the 256 data points of each pixel (G=0→L0, G=1→L1,..., G=255→L255) according to their grayscale values ​​to form the grayscale-brightness curve of that pixel (the horizontal axis is grayscale G, and the vertical axis is brightness L).

[0053] Step S202: Divide the gray-scale-brightness curve corresponding to each pixel into segments to obtain N curve segments for each pixel, and perform linear fitting on the N curve segments for each pixel to obtain N linear functions for each pixel. The N curve segments for each pixel correspond to the N gray-scale intervals for each pixel, and N is an integer greater than 1.

[0054] Specifically, the value of N can be any integer greater than 1, and can be set according to actual needs. Since the grayscale-brightness curve of each pixel is usually non-linear, for example, suppose a pixel's brightness increases slowly in the low grayscale range (0-63) (e.g., L=0 when G=0, L=50cd / ㎡ when G=32), increases faster in the medium grayscale range (64-191) (e.g., L=300cd / ㎡ when G=128), and flattens out in the high grayscale range (192-255) (e.g., L=500cd / ㎡ when G=255). If a single linear function is used to fit the pixel across the entire 0-255 grayscale range, it will lead to overcompensation at low grayscale levels and undercompensation at high grayscale levels (because a single linear function cannot capture non-linear characteristics). Therefore, it is necessary to divide the non-linear curve into multiple segments, and fit each segment with a linear function to reduce the overall error of the non-linear curve.

[0055] To better fit the grayscale-luminance curve of each pixel, the grayscale-luminance curve corresponding to each pixel can be segmented to obtain N curve segments for each pixel. Then, linear fitting is performed on these N curve segments to obtain N linear functions for each pixel. As an optional implementation, the value of N can be 8, thus dividing the grayscale-luminance curve of each pixel into 8 grayscale intervals, each corresponding to a curve segment. Each grayscale interval can contain 32 grayscale levels; for example, the grayscale range of the first grayscale interval is 0-31, the grayscale range of the second grayscale interval is 32-63, and so on, with the grayscale range of the eighth grayscale interval being 224-255. Thus, linear fitting on each curve segment yields a linear function for each curve segment. The linear function here can be represented by L0. i =a i *G i +b i Let L represent this, where L i G represents brightness. i Indicates grayscale, a i b represents the slope. i denoted as the intercept, and i represents the i-th grayscale interval.

[0056] Step S203: Obtain the position information of each pixel, and adjust the slope of the N linear functions of each pixel according to the position information of each pixel.

[0057] Specifically, the aforementioned location information can be understood as the position coordinate information of each pixel. Due to the IR drop effect, the edge pixels of the display panel are prone to low brightness. Therefore, based on the position information of each pixel, the slope of the N linear functions of each pixel can be adjusted, that is, the slope of the edge pixels can be increased to improve the brightness of the edge pixels.

[0058] Step S204: Based on the N linear functions after adjusting the slope of each pixel, compensate for the grayscale of each pixel in the image to be displayed to obtain the compensated image, and then display the compensated image.

[0059] After obtaining N linear functions with adjusted slopes for each pixel, the grayscale of each pixel in the image to be displayed can be compensated based on the slope and intercept of the N linear functions with adjusted slopes for each pixel, thus obtaining the compensated image, and finally the compensated image is displayed.

[0060] By using the above method, the grayscale-brightness curve corresponding to each pixel can be segmented and then linearly fitted to obtain N linear functions for each pixel. This results in the non-linear relationship of the grayscale-brightness curve for each pixel, effectively avoiding inaccurate compensation caused by uniform compensation for static and non-static pixels. Furthermore, the slope of the N linear functions for each pixel can be adaptively adjusted based on the position information of each pixel, further eliminating the problem of low brightness in edge pixels. This improves the uniformity of brightness of the display panel and thus enhances the display effect of the display panel.

[0061] In an optional embodiment, step S202, which involves linearly fitting the N curve segments of each pixel to obtain N linear functions for each pixel, includes:

[0062] The least squares method is used to perform linear fitting on the N curve segments of each pixel to determine the fitting parameters of the N curve segments of each pixel. The fitting parameters include a first parameter used to characterize the slope of the N linear functions of each pixel and a second parameter used to characterize the intercept of the N linear functions of each pixel.

[0063] Based on the first and second parameters, N linear functions for each pixel are obtained.

[0064] Specifically, when performing linear fitting on the N curve segments of each pixel, the least squares method can be used to perform linear fitting on the N curve segments of each pixel, thereby determining the fitting parameters for the N curve segments of each pixel. These fitting parameters can include a first parameter characterizing the slope of the N linear functions for each pixel and a second parameter characterizing the intercept of the N linear functions for each pixel. Then, based on the first and second parameters, the N linear functions for each pixel can be obtained.

[0065] For example, the gray-level-luminance curve L = f(G) corresponding to each pixel is divided into 8 gray-level intervals. Let's assume that a certain gray-level interval is represented by [G]. min G max If we use the least squares method, we can obtain the slope of the linear function for this grayscale range as follows: The intercept of the linear function in this grayscale range is in, Let be the average gray value of gray range i. Let be the average brightness value of grayscale interval i.

[0066] By employing the above method, piecewise linear fitting of N curve segments for each pixel allows for the estimation of the non-linear relationship between the grayscale and brightness curves of each pixel. This effectively avoids the inaccuracy caused by uniform compensation for both static and non-static pixels, thus effectively solving the problem of inaccurate low / high grayscale compensation resulting from the assumption of a linear grayscale-brightness curve in traditional methods. Furthermore, the computational cost of piecewise linear fitting is far less than that of polynomial fitting (only N linear functions need to be calculated for each pixel), supporting a high refresh rate of 120Hz.

[0067] In an optional embodiment, step S203, obtaining the position information of each pixel and adjusting the slope of the N linear functions of each pixel based on the position information of each pixel, includes:

[0068] Obtain the position information of each pixel, and calculate the distance from each pixel to the center of the display panel based on the position information of each pixel;

[0069] Calculate the ratio of the distance to the diagonal length of the display panel;

[0070] Based on the ratio, the slopes of N linear functions for each pixel are adjusted, where the adjustment amount of the slopes of the N linear functions for each pixel is positively correlated with the ratio.

[0071] Specifically, when adjusting the slopes of the N linear functions for each pixel, the position information of each pixel can be obtained, and the distance from each pixel to the center of the display panel can be calculated based on the position information of each pixel. This can be achieved using the following formula:

[0072]

[0073] Where d(x,y) represents the distance from pixel (x,y) to the center of the display panel, W represents the total width of the display panel, and H represents the total height of the display panel. This represents the coordinates of the center of the display panel. In one optional implementation, W = 1920, H = 1080.

[0074] Then calculate the ratio of this distance to the diagonal length of the display panel, which can be achieved using the following formula:

[0075] dn(x,y)=d(x,y) / dmax;

[0076] Where dn(x,y) represents the ratio of the distance from pixel (x,y) to the center of the display panel to the length of the diagonal of the display panel, d(x,y) represents the distance from pixel (x,y) to the center of the display panel, and dmax represents the length of the diagonal of the display panel.

[0077] Next, the slopes of the N linear functions for each pixel can be adjusted based on this ratio.

[0078] This allows for a larger slope for pixels near the edge of the display panel, and a smaller slope for pixels near the center. Through spatial adaptive gain adjustment, the problem of low brightness in edge pixels caused by the IR drop effect is solved, and the edge mura reduction rate is improved by 20%.

[0079] In an optional embodiment, the slopes of the N linear functions for each pixel are adjusted according to the following formula:

[0080] a i ′=a i ·(1+k·dn(x,y));

[0081] Among them, a i ′ represents the slope of pixel (x,y) adjusted by i linear functions, a i dn(x,y) represents the slope of the i linear functions of pixel (x,y) before adjustment, k represents the preset coefficient, and dn(x,y) represents the ratio of the distance from pixel (x,y) to the center of the display panel to the length of the diagonal of the display panel.

[0082] Specifically, according to the formula above, the preset coefficient k is usually a positive number, which can be 0.1 or other values. When k = 0.1, it means that for every unit increase in the length of the ratio dn(x,y), the slope of the edge pixel increases by 10%, thereby increasing the brightness of the edge pixel.

[0083] In this way, the slope of the N linear functions of each pixel can be adaptively adjusted according to the position information of each pixel, further solving the problem of low brightness of edge pixels caused by IR Drop effect, thus improving the uniformity of brightness of the display panel and thus improving the display effect of the display panel.

[0084] In an optional embodiment, step S204, which involves compensating the grayscale of each pixel in the image to be displayed based on N linear functions adjusted for the slope of each pixel to obtain a compensated image, includes:

[0085] Obtain the actual grayscale and target brightness of each pixel in the image to be displayed;

[0086] Based on the actual gray level of each pixel, determine the target linear function for each pixel, where the gray level range corresponding to the target linear function includes the actual gray level of the corresponding pixel;

[0087] The grayscale value of each pixel after compensation is calculated using the target linear function and the target brightness of each pixel.

[0088] The actual gray level of each pixel is compensated according to the gray level of each pixel after compensation, and the compensated image is obtained.

[0089] Specifically, when compensating for the grayscale of each pixel in the image to be displayed, the actual grayscale and target brightness of each pixel in the image can be obtained. The target brightness can be understood as the brightness required for the display panel to uniformly display the image, such as the average brightness of the display panel, like 200 cd / m². 2 Then, based on the actual gray level of each pixel, the target linear function of each pixel can be determined. Next, using the target linear function and target brightness of each pixel, the compensated gray level of each pixel can be calculated. Finally, the actual gray level of each pixel is compensated according to the compensated gray level of each pixel to obtain the compensated image.

[0090] For example, suppose the grayscale-luminance curve L = f(G) of a certain pixel is as follows: when G = 0, L = 0 cd / m²; when G = 31, L = 50 cd / m²; when G = 63, L = 150 cd / m²; when G = 95, L = 300 cd / m²; when G = 127, L = 450 cd / m²; when G = 159, L = 550 cd / m²; when G = 191, L = 600 cd / m²; when G = 223, L = 630 cd / m²; when G = 255, L = 650 cd / m². After piecewise linear fitting, the results are as follows: Interval 1 (0-31): L = 1.613G + 0 (a1 = 1.613, b1 = 0); Interval 2 (32-63): L = 3.125G - 50 (a2 = 3.125, b2 = -50); Interval 3 (64-95): L = 4.6875G - 150 (a3 = 4.6875, b3 = -150); Subsequent intervals are similar.

[0091] The final compensation effect is as follows: Assuming the target brightness of the pixel is 300 cd / m², and the actual grayscale G = 95, it belongs to the 3rd interval, the calculation is as follows: Therefore, by increasing the grayscale of this pixel from 95 to 96, the brightness of this pixel can reach the target brightness of 300 cd / m², consistent with the brightness of other pixels. In this way, the target linear function of each pixel can be determined based on its actual grayscale, that is, the slope and intercept corresponding to each pixel, thereby achieving precise compensation for each grayscale level pixel and improving the uniformity of brightness.

[0092] In an optional embodiment, the above steps, including calculating the compensated grayscale of each pixel using the target linear function and the target brightness of each pixel, include:

[0093] Calculate the difference between the target brightness of the target pixel and the intercept of the target linear function of the target pixel, where the target pixel is any pixel in the display panel;

[0094] Calculate the ratio between the difference and the slope of the target linear function for the target pixel;

[0095] The ratio is determined as the grayscale value after compensation for the target pixel.

[0096] Specifically, when calculating the grayscale of a target pixel after compensation using the target linear function and target brightness of the target pixel, the difference between the target brightness of the target pixel and the intercept of the target linear function of the target pixel can be calculated first. Then, the ratio between the difference and the slope of the target linear function of the target pixel can be calculated, and the ratio can be determined as the grayscale of the target pixel after compensation.

[0097] Using the above method, the grayscale of each pixel after compensation can be accurately calculated, thereby obtaining a compensated image with uniform brightness.

[0098] In an optional embodiment, the formula for calculating the grayscale of the target pixel after compensation is as follows:

[0099] G(x,y)=(Target_L-b j ) / a j ′;

[0100] Where G(x,y) represents the grayscale value of the target pixel after compensation, Target_L represents the target brightness of the target pixel, and b j a represents the intercept of the linear function of the target pixel. j ′ represents the slope of the target linear function for the target pixel.

[0101] Specifically, the above formula G(x,y)=(Target_L-b) can be used to express the following: j ) / a j Transformed into the formula G(x,y)=clip((Target_L-b) j ) / a j ′,0,255), where the clip function is used to limit the result to an 8-bit range of 0-255.

[0102] For example, suppose the parameters of the linear function for a pixel in grayscale range 4 (i.e., grayscale levels 96-127) are: a4 = 2.5 (original slope), b4 = 10 (original intercept). Because this pixel is located at the edge of the screen, a4′ is adjusted to a4 × 1.1 = 2.75 (to compensate for the slope attenuation caused by IR drop), the average panel brightness TargetL = 300 cd / m², and the actual grayscale level of this pixel G = 100 (belonging to range 4). The processing procedure is as follows:

[0103] Define the range: grayscale 100 belongs to grayscale range 4 (96≤100<128);

[0104] Extracted parameters: a4′=2.75, b4=10;

[0105] Calculate G(x,y):

[0106] Limitation range: clip(105.45,0,255) = 105 (rounded down). Using the above method, the grayscale of each pixel after compensation can be accurately calculated, thus obtaining a compensated image with uniform brightness.

[0107] In an optional implementation, the brightness compensation method of the display panel provided in this application embodiment can be as follows: Figure 3 As shown, taking an 8-bit display as an example, the specific steps include the following:

[0108] Step S301: Input the image to be displayed.

[0109] Convert the image to be displayed into a grayscale image (8-bit, 0-255).

[0110] Step S302: Gray-scale-brightness curve acquisition.

[0111] The grayscale-luminance curve of each pixel can be measured using a luminance meter or a charge-coupled device (CCD).

[0112] Step S303: Piecewise linear fitting.

[0113] Because the brightness change across the entire grayscale range is non-linear—for example, the brightness change is slow in dark areas (low grayscale) and fast in bright areas (high grayscale)—the grayscale-brightness curve of each pixel can be divided into 8 segments. Each segment's brightness change is closer to a "linear line," making adjustments more precise. Furthermore, dividing the grayscale-brightness curve of each pixel into multiple intervals (e.g., 8 intervals, each corresponding to 32 grayscale levels), and fitting each interval with a linear function, can reduce the computational load.

[0114] Step S304: Spatial adaptive gain calculation.

[0115] The slope of the segmented linear algorithm is adjusted based on the spatial location of the pixels (distance from the center of the screen). The slope of edge pixels is increased (to improve brightness), which solves edge mura caused by IR drop and avoids "overly bright edges" or "halo effect", such as dark spots at the edge of the screen. After adjustment, the edges will not be brighter than the center, making the brightness transition of the entire screen more natural.

[0116] Step S305: Gray-level adaptive compensation.

[0117] Each gray level corresponds to an independent compensation gain, avoiding the nonlinearity problem caused by a single gain in traditional methods.

[0118] Step S306: Output the compensated grayscale image.

[0119] Output the compensated 8-bit grayscale image (8-bit, 0-255).

[0120] For ease of explanation, we will use a 1080P (1920×1080) OLED display panel as an example to simulate Mura, adding block effect Mura (randomly selecting 10 20×20 pixel blocks, reducing brightness by 20%) and edge Mura (15% reduction in brightness of the 100 pixels at the edge).

[0121] Comparison of methods: ① Traditional brightness compensation method (single gain); ② Polynomial fitting compensation method (third-order polynomial);

[0122] Evaluation metrics include: brightness uniformity such as the coefficient of variation (CV, where CV = σ / μ, σ is the standard deviation of brightness, and μ is the mean of brightness; the smaller the CV, the better the brightness uniformity; image sharpness such as peak signal-to-noise ratio (PSNR); and processing efficiency such as processing time per frame.

[0123] The simulation results are shown in the table below:

[0124]

[0125] Therefore, regarding brightness uniformity: the CV of the brightness compensation method for the display panel provided in this application embodiment is 2.8%, which is much lower than the traditional single-gain brightness compensation method (8.1%) and polynomial fitting compensation method (4.5%), indicating that edge mura and block effect mura are effectively eliminated. Regarding image sharpness: the PSNR of the brightness compensation method for the display panel provided in this application embodiment is 48.2dB, which is higher than the traditional single-gain brightness compensation method (42.5dB) and polynomial fitting compensation method (45.1dB), indicating that the compensated image is sharper. Regarding processing efficiency: the calculation time of the brightness compensation method for the display panel provided in this application embodiment is 12.3ms / frame, which is slightly higher than the traditional single-gain brightness compensation method (8.5ms), but much lower than the polynomial fitting compensation method (25.7ms), and supports a 120Hz high refresh rate (each frame requires <8.3ms, which can be accelerated and optimized to <8ms through the graphics processing unit (GPU)). Therefore, the brightness compensation method for the display panel provided in this application has the following beneficial effects:

[0126] (1) Nonlinear correction: By fitting the gray-brightness curve of OLED in a piecewise linear manner, the problem of inaccurate compensation for low gray-scale / high gray-scale caused by ignoring nonlinearity in traditional methods is solved.

[0127] (2) Good real-time performance: The computational cost of piecewise linear fitting is much smaller than that of polynomial fitting (only 8 linear functions need to be calculated for each pixel), and it supports a high refresh rate of 120Hz.

[0128] (3) Spatial uniformity: By adjusting the spatial adaptive gain, the problem of low edge pixel brightness caused by IR Drop is solved, and the edge mura elimination rate is improved by 20%;

[0129] (4) High accuracy: Each gray level corresponds to an independent compensation gain, and the brightness uniformity (coefficient of variation CV) is reduced from 8% in the traditional method to less than 3%.

[0130] See Figure 4 , Figure 4 This is a schematic diagram of the structure of a brightness compensation device for a display panel provided in an embodiment of this application. Figure 4 As shown, the brightness compensation device 400 of the display panel includes:

[0131] The acquisition module 401 is used to acquire the image to be displayed and the grayscale-brightness curves corresponding to each pixel in the display panel. The display panel is used to display the image to be displayed.

[0132] The segmentation and fitting module 402 is used to segment the gray-level-brightness curve corresponding to each pixel to obtain N curve segments of each pixel, and to perform linear fitting on the N curve segments of each pixel to obtain N linear functions of each pixel. Here, the N curve segments of each pixel correspond to the N gray-level intervals of each pixel, and N is an integer greater than 1.

[0133] The adjustment module 403 is used to obtain the position information of each pixel and adjust the slope of the N linear functions of each pixel according to the position information of each pixel;

[0134] The compensation module 404 is used to compensate the grayscale of each pixel in the image to be displayed based on N linear functions after adjusting the slope of each pixel, to obtain the compensated image, and to display the compensated image.

[0135] Furthermore, the segmentation and fitting module 402 includes:

[0136] The linear fitting submodule is used to perform linear fitting on the N curve segments of each pixel using the least squares method, and to determine the fitting parameters of the N curve segments of each pixel. The fitting parameters include a first parameter that characterizes the slope of the N linear functions of each pixel and a second parameter that characterizes the intercept of the N linear functions of each pixel.

[0137] The first determining submodule is used to obtain N linear functions for each pixel based on the first parameter and the second parameter.

[0138] Furthermore, adjustment module 403 includes:

[0139] The first acquisition submodule is used to acquire the position information of each pixel and calculate the distance from each pixel to the center of the display panel based on the position information of each pixel.

[0140] The first calculation submodule is used to calculate the ratio of the distance to the diagonal length of the display panel;

[0141] The adjustment submodule is used to adjust the slope of N linear functions for each pixel based on the ratio, wherein the adjustment amount of the slope of the N linear functions for each pixel is positively correlated with the ratio.

[0142] Furthermore, the slopes of the N linear functions for each pixel are adjusted according to the following formula:

[0143] a i ′=a i ·(1+k·dn(x,y));

[0144] Among them, a i ′ represents the slope of pixel (x,y) adjusted by i linear functions, a idn(x,y) represents the slope of the i linear functions of pixel (x,y) before adjustment, k represents the preset coefficient, and dn(x,y) represents the ratio of the distance from pixel (x,y) to the center of the display panel to the length of the diagonal of the display panel.

[0145] Furthermore, the compensation module 404 includes:

[0146] The second acquisition submodule is used to acquire the actual grayscale and target brightness of each pixel in the image to be displayed;

[0147] The second determining submodule is used to determine the target linear function of each pixel based on the actual gray level of each pixel, wherein the gray level range corresponding to the target linear function includes the actual gray level of the corresponding pixel.

[0148] The second calculation submodule is used to calculate the compensated grayscale of each pixel using the target linear function of each pixel and the target brightness of each pixel.

[0149] The compensation submodule is used to compensate the actual gray level of each pixel according to the gray level of each pixel after compensation, so as to obtain the compensated image.

[0150] Furthermore, the compensation submodule includes:

[0151] The first calculation unit is used to calculate the difference between the target brightness of the target pixel and the intercept of the target linear function of the target pixel, wherein the target pixel is any pixel in the display panel;

[0152] The second calculation unit is used to calculate the ratio between the difference and the slope of the target linear function of the target pixel;

[0153] The determination unit is used to determine the ratio as the grayscale value after compensation for the target pixel.

[0154] Furthermore, the formula for calculating the grayscale value of the target pixel after compensation is as follows:

[0155] G(x,y)=(Target_L-b j ) / a j ′;

[0156] Where G(x,y) represents the grayscale value of the target pixel after compensation, Target_L represents the target brightness of the target pixel, and b j a represents the intercept of the linear function of the target pixel. j ′ represents the slope of the target linear function for the target pixel.

[0157] It should be noted that the brightness compensation device 400 of the display panel can realize the brightness compensation method of the display panel provided in any of the aforementioned method embodiments, and can achieve the same technical effect, which will not be described in detail here.

[0158] See Figure 5 , Figure 5 This is a schematic diagram of the structure of a display device provided in an embodiment of this application, such as... Figure 5 As shown, the display device 500 includes: a display panel 501 and a brightness compensation device 502 for the display panel in the aforementioned embodiment;

[0159] The display panel 501 and the brightness compensation device 502 of the display panel are electrically connected.

[0160] It should be noted that the display device 500 can be any device with a display panel, such as a mobile phone, computer, television, or wearable device, and there are no restrictions on this.

[0161] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the brightness compensation method for a display panel as provided in any of the foregoing method embodiments.

[0162] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0163] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented using software plus a general-purpose hardware platform, or of course, using hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0164] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0165] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A brightness compensation method for a display panel, characterized in that, The method includes: The image to be displayed is obtained, as well as the grayscale-brightness curves corresponding to each pixel in the display panel, which is used to display the image to be displayed; The gray-scale-brightness curve corresponding to each pixel is segmented to obtain N curve segments for each pixel. Then, the N curve segments for each pixel are linearly fitted to obtain N linear functions for each pixel. The N curve segments for each pixel correspond to the N gray-scale intervals of each pixel, and N is an integer greater than 1. Obtain the position information of each pixel, and adjust the slope of N linear functions for each pixel based on the position information of each pixel; Based on N linear functions adjusted by the slope of each pixel, the grayscale of each pixel in the image to be displayed is compensated to obtain a compensated image, and the compensated image is then displayed.

2. The method according to claim 1, characterized in that, The process of linearly fitting N curve segments of each pixel to obtain N linear functions for each pixel includes: The least squares method is used to perform linear fitting on N curve segments of each pixel to determine the fitting parameters of N curve segments of each pixel. The fitting parameters include a first parameter for characterizing the slope of N linear functions of each pixel and a second parameter for characterizing the intercept of N linear functions of each pixel. Based on the first parameter and the second parameter, N linear functions for each pixel are obtained.

3. The method according to claim 1, characterized in that, The step of obtaining the position information of each pixel and adjusting the slope of N linear functions for each pixel based on the position information of each pixel includes: Obtain the position information of each pixel, and calculate the distance from each pixel to the center of the display panel based on the position information of each pixel; Calculate the ratio of the distance to the diagonal length of the display panel; Based on the ratio, the slopes of the N linear functions for each pixel are adjusted, wherein the adjustment amount of the slopes of the N linear functions for each pixel is positively correlated with the ratio.

4. The method according to claim 3, characterized in that, The slopes of the N linear functions for each pixel are adjusted according to the following formula: a i ′=a i ·(1+k·dn(x,y)); Among them, a i ′ represents the slope of pixel (x,y) adjusted by i linear functions, a i The slope of pixel (x,y) before adjustment by the i linear functions is represented, k represents the preset coefficient, and dn(x,y) represents the ratio of the distance from pixel (x,y) to the center of the display panel to the length of the diagonal of the display panel.

5. The method according to claim 1, characterized in that, The grayscale of each pixel in the image to be displayed is compensated using N linear functions adjusted based on the slope of each pixel to obtain a compensated image, including: Obtain the actual grayscale and target brightness of each pixel in the image to be displayed; Based on the actual gray level of each pixel, a target linear function for each pixel is determined, wherein the gray level range corresponding to the target linear function includes the actual gray level of the corresponding pixel; The grayscale value of each pixel after compensation is calculated using the target linear function and the target brightness of each pixel. The actual gray level of each pixel is compensated according to the gray level of each pixel after compensation, to obtain the compensated image.

6. The method according to claim 5, characterized in that, The calculation of the compensated grayscale of each pixel using the target linear function and the target brightness of each pixel includes: Calculate the difference between the target brightness of the target pixel and the intercept of the target linear function of the target pixel, wherein the target pixel is any pixel in the display panel; Calculate the ratio between the difference and the slope of the target linear function of the target pixel; The ratio is determined as the grayscale value of the target pixel after compensation.

7. The method according to claim 5, characterized in that, The formula for calculating the grayscale of the target pixel after compensation is as follows: G(x,y)=(Target_L-b j ) / a j ′; Where G(x,y) represents the grayscale of the target pixel after compensation, Target_L represents the target brightness of the target pixel, and b j a represents the intercept of the target linear function of the target pixel. j ′ represents the slope of the target linear function of the target pixel.

8. A brightness compensation device for a display panel, characterized in that, The device includes: An acquisition module is used to acquire an image to be displayed and the grayscale-brightness curves corresponding to each pixel in the display panel, wherein the display panel is used to display the image to be displayed; The segmentation and fitting module is used to segment the gray-level-brightness curve corresponding to each pixel to obtain N curve segments for each pixel, and to perform linear fitting on the N curve segments for each pixel to obtain N linear functions for each pixel. Here, the N curve segments for each pixel correspond to the N gray-level intervals for each pixel, and N is an integer greater than 1. The adjustment module is used to obtain the position information of each pixel and adjust the slope of N linear functions of each pixel according to the position information of each pixel; The compensation module is used to compensate the grayscale of each pixel in the image to be displayed based on N linear functions adjusted by the slope of each pixel, to obtain a compensated image, and to display the compensated image.

9. A display device, characterized in that, The display device includes: a display panel and a brightness compensation device for the display panel as described in claim 8; The display panel and the brightness compensation device of the display panel are electrically connected.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the brightness compensation method for the display panel according to any one of claims 1-7.

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