Brightness compensation method, electronic device, storage medium and computer program product

Abstract

The present disclosure provides a brightness compensation method, an electronic device, a storage medium and a computer program product. The brightness compensation method comprises: obtaining a gray value of a first image frame and a second image frame, the second image frame being a to-be-displayed image frame, and the first image frame being a previous frame of the to-be-displayed image frame; the gray value of the first image frame is denoted as a first gray value, and the gray value of the second image frame is denoted as a second gray value; searching for a voltage compensation parameter corresponding to the first gray value and the second gray value from a lookup table according to the first gray value and the second gray value, the lookup table comprising a plurality of voltage compensation parameters, each voltage compensation parameter corresponding to a third gray value and a fourth gray value; obtaining a data voltage of the second image frame, compensating the data voltage by using the voltage compensation parameter, and driving a display panel to display the second image frame by using the compensated data voltage.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of display. More particularly, it relates to a brightness compensation method, an electronic device, a storage medium and a computer program product. BACKGROUND

[0002] AMOLED (Active Matrix Organic Light Emitting Diode) display screens have been widely used in high-end display devices due to their excellent color performance, high contrast and low power consumption. However, in the process of switching black and white pictures of the AMOLED display screen, due to the influence of the driving circuit and the device structure, a problem will be caused: the brightness of the first frame of white picture is often lower than the final determined white brightness value, that is, the first frame brightness is insufficient. For the more sensitive human eyes, the phenomenon is that the first frame after switching pictures will appear trailing, which is usually represented by FFR (First Frame Ratio). The lower the FFR value, the more obvious the trailing. SUMMARY

[0003] The purpose of the present disclosure is to provide a brightness compensation method, an electronic device, a storage medium and a computer program product to solve the technical problem of insufficient first frame brightness when switching display pictures in the related art.

[0004] To achieve the above purpose, the present disclosure adopts the following technical solution:

[0005] The first aspect of the present disclosure provides a brightness compensation method, comprising the following steps:

[0006] obtaining the gray values of a first image frame and a second image frame, the second image frame being a to-be-displayed image frame, the first image frame being a previous frame of the to-be-displayed image frame, the gray value of the first image frame being denoted as a first gray value, and the gray value of the second image frame being denoted as a second gray value;

[0007] looking up a voltage compensation parameter corresponding to the first gray value and the second gray value from a pre-stored lookup table according to the first gray value and the second gray value, the lookup table including a plurality of voltage compensation parameters, each voltage compensation parameter corresponding to a third gray value and a fourth gray value, and the voltage compensation parameter representing a compensation parameter that satisfies a first frame brightness ratio greater than a preset value when the display panel switches from a display picture of the third gray value to a display picture of the fourth gray value;

[0008] obtaining a data voltage of the second image frame, compensating the data voltage by using the voltage compensation parameter, and driving the display panel to display the second image frame by using the compensated data voltage.

[0009] Optionally, the voltage compensation parameter is a voltage compensation value; compensating the data voltage by the voltage compensation parameter comprises:

[0010] adding the voltage compensation value and the data voltage to obtain the compensated data voltage.

[0011] Optionally, the voltage compensation parameter is a voltage compensation coefficient; compensating the data voltage by the voltage compensation parameter comprises:

[0012] multiplying the voltage compensation coefficient and the data voltage to obtain the compensated data voltage.

[0013] Optionally, the brightness compensation method further comprises:

[0014] obtaining a voltage compensation parameter when the display panel is switched from a first test picture to a second test picture, the first test picture having a third gray value, the second test picture having a fourth gray value, the third gray value, the fourth gray value and the voltage compensation parameter constituting a group of reference data;

[0015] obtaining a plurality of groups of the reference data, and establishing a lookup table according to the plurality of groups of the reference data, wherein the third gray value corresponding to each group of the reference data is different and / or the fourth gray value corresponding to each group of the reference data is different.

[0016] Optionally, the second test picture comprises a plurality of frames, and the step of obtaining the voltage compensation parameter when the display panel is switched from the first test picture to the second test picture, the first frame having a brightness ratio greater than a preset value, comprises:

[0017] setting a plurality of voltage compensation parameters;

[0018] for any voltage compensation parameter, obtaining a brightness of the display panel when displaying the first test picture as an original brightness, a brightness of the display panel when displaying a first frame of the second test picture as a first brightness, a brightness of the display panel when displaying a second frame of the second test picture as a second brightness, and calculating a first frame brightness ratio corresponding to the voltage compensation parameter according to the original brightness, the first brightness and the second brightness;

[0019] obtaining the voltage compensation parameter from the plurality of voltage compensation parameters corresponding to the first frame brightness ratio, the first frame brightness ratio being greater than a preset value.

[0020] Optionally, the step of searching for the voltage compensation parameter corresponding to the first gray value and the second gray value from the pre-stored lookup table according to the first gray value and the second gray value comprises:

[0021] searching for a third gray value closest to the first gray value and a fourth gray value closest to the second gray value from the pre-stored lookup table.

[0022] The voltage compensation parameter corresponding to the third and fourth gray scale values is taken as the voltage compensation parameter corresponding to the first and second gray scale values.

[0023] Optionally, the lookup table comprises a plurality of sub-tables, each sub-table corresponding to a brightness level; and the step of searching the voltage compensation parameter corresponding to the first and second gray scale values from the pre-stored lookup table comprises:

[0024] A brightness level currently set by the display panel is taken as a first brightness level;

[0025] The voltage compensation parameter corresponding to the first and second gray scale values is searched from the sub-table corresponding to the first brightness level.

[0026] Optionally, the step of obtaining the gray scale values of the first and second image frames comprises:

[0027] The first image frame is divided into a plurality of first image blocks, the gray scale value of each first image block is taken as a first sub-gray scale value, and a set of first sub-gray scale values of all first image blocks constitutes the first gray scale value;

[0028] The second image frame is divided into a plurality of second image blocks corresponding to the first image blocks one by one, the gray scale value of each second image block is taken as a second sub-gray scale value, and a set of second sub-gray scale values of all second image blocks constitutes the second gray scale value;

[0029] The step of searching the voltage compensation parameter corresponding to the first and second gray scale values from the pre-stored lookup table comprises:

[0030] For any first image block and corresponding second image block, the voltage compensation parameter corresponding to the first and second sub-gray scale values is searched from the lookup table according to the first sub-gray scale value corresponding to the first image block and the second sub-gray scale value corresponding to the second image block.

[0031] Optionally, the step of taking the average value of the gray scale values of all pixels in the first image block as the first sub-gray scale value comprises:

[0032] The average value of the gray scale values of all pixels in the first image block is calculated;

[0033] The average value is taken as the first sub-gray scale value corresponding to the first image block.

[0034] The second aspect of the present disclosure provides an electronic device, comprising a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor is configured to read the program in the memory to implement the steps of the brightness compensation method.

[0035] The third aspect of the present disclosure provides a computer-readable storage medium, which stores a computer program, wherein the program is executable by a processor to implement the steps of the brightness compensation method.

[0036] The fourth aspect of the present disclosure provides a computer program product, comprising a computer program, wherein the program is executable by a processor to implement the steps of the brightness compensation method.

[0037] The present disclosure has the following beneficial effects:

[0038] The brightness compensation method of the present disclosure measures and stores a lookup table in advance, wherein the lookup table comprises voltage compensation parameters that make the first-frame brightness ratio after switching greater than a preset value when the display panel switches from a picture of a third gray scale value to a picture of a fourth gray scale value, and when the display panel performs picture switching, the voltage compensation parameters are looked up by using the gray scale values of a to-be-displayed image frame and a previous frame of the to-be-displayed image frame, and the data voltage of the to-be-displayed image frame is compensated by using the looked-up voltage compensation parameters, so that the problem of first-frame brightness reduction caused by IR Drop during picture switching can be compensated, and the FFR performance can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0039] The specific embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0040] Figure 1 A schematic diagram of insufficient first-frame brightness when a black-and-white picture of a display screen is switched;

[0041] Figure 2 A schematic diagram of the principle that IR Drop causes the brightness of the first few frames of a white picture to be lower than a certain value when a black-and-white picture is switched;

[0042] Figure 3 A basic structure diagram of a pixel driving circuit of a display panel;

[0043] Figure 4 A flowchart of the brightness compensation method provided by the present disclosure;

[0044] Figure 5 A schematic diagram of dividing a first image frame into a plurality of first image blocks;

[0045] Figure 6 A schematic diagram of operation time when the compensation IP compensates for different gray scale display pictures in reverse;

[0046] Figure 7 To make the display brightness of each frame before and after switching in the related art when switching from a G0 picture to a G255 picture;

[0047] Figure 8 To make the display brightness of each frame before and after switching in the related art when switching from a G0 picture to a G255 picture;

[0048] Figure 9 The flowchart of establishing the lookup table provided by the embodiment of the present disclosure. DETAILED DESCRIPTION

[0049] To make the display brightness of each frame before and after switching in the related art when switching from a G0 picture to a G255 picture;

[0050] Unless otherwise defined, technical terms or scientific terms used in the present disclosure shall have the ordinary meaning understood by a person of ordinary skill in the art to which the present disclosure pertains. The terms "first", "second", and similar terms used in the present disclosure do not indicate any order, number, or importance, but are only used to distinguish different components. Similarly, the terms "one", "an", or "the" and similar terms do not indicate a quantity limitation, but indicate the presence of at least one. The terms "include" or "contain" and similar terms mean that the elements or objects before the term encompass the elements or objects listed after the term and their equivalents, without excluding other elements or objects. The terms "connect" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "up", "down", "left", "right", and the like only represent relative positional relationships, which can change when the absolute positions of the described objects change.

[0051] FFR is an important parameter in display screen optical performance, which affects the smoothness of dynamic images and visual experience. High first frame refresh rate means that the screen can update images more frequently, reduce dynamic blur and motion blur, and provide a smoother visual experience. Please refer to Figure 1 , Figure 1 The schematic diagram of insufficient first frame brightness when switching between black and white pictures of the display screen, Figure 1 The horizontal coordinate represents time, the vertical coordinate represents optical response, and the curve represents the current curve, Figure 1The 0th Frame represents a black picture frame, the 1st Frame, the 2nd Frame and the 3rd Frame represent the first frame white picture, the second frame white picture and the third frame white picture after the black picture frame respectively, R1, R2 and R0 represent the average brightness of the 1st Frame, the 2nd Frame and the 3rd Frame respectively, wherein the white brightness of the third frame white picture and each frame white picture after the third frame white picture tends to be stable, and R0 can also be understood as the average brightness of each frame after the white brightness is stable (no longer increases every frame), which is determined by Figure 1 It can be seen that the brightness of the first few frames (especially the first frame) of the white picture is often lower than the final determined white picture brightness value R0 when the display screen switches from a black picture to a white picture. This phenomenon can be caused by some factors such as TFT (Thin Film Transistor) hysteresis effect or IR Drop (current reduction).

[0052] Please refer to Figures 2-3 , Figure 2 When the black picture is switched to the white picture, the principle diagram of IR Drop causing the brightness of the first few frames of the white picture to be lower than the determined value is shown. As Figure 2 shown, the equivalent resistance of all the parallel sub-pixel units (for example, each R, G and B sub-pixel constitutes a sub-pixel unit, which can also be understood as a pixel) in the display area of the display screen is defined as Rx, and the resistance of the ELVDD voltage lead wire not including the sub-pixel unit is defined as R0, which is a fixed value in the display screen. As Figure 2 shown, Rx and R0 are in series, both pass through the same current I, therefore, the resistance R0 occupies part of the voltage, that is, V Drop = I x R0. During the display process, the current I will change with different display patterns, thereby causing V Drop to change accordingly, and the influence of V Drop will cause the voltage allocated to the parallel sub-pixel units in the display area to also change simultaneously, that is, Real ELVDD = ELVDD - I x R0. This phenomenon that the Real ELVDD of the sub-pixel unit is different due to different display loads (display patterns) is called IR Drop. Affected by the IR Drop, the Real ELVDD is variable, therefore the current I of the sub-pixel unit is simultaneously affected by the Real ELVDD and V Data variable.

[0053] The causes of the IR Drop will be analyzed in detail below, Figure 3 Figure 3 ​This is a basic structural diagram of a pixel driving circuit for a display panel in the related art. This pixel driving circuit is a typical 7T1C driving circuit, in which transistor T1 is a reset transistor, transistor T4 is a data input transistor, transistor T3 is a driving transistor, transistor T2 is a compensation transistor, transistors T5 and T7 are light-emitting control transistors, and transistor T6 is a reset transistor. The control electrodes of transistors T2 and T4 are electrically connected to the row scan terminal to receive the row scan signal Gate, the control electrode of transistor T1 is electrically connected to the reset control terminal to receive the reset control signal RESET, and the drain of transistor T4 is connected to the data voltage V Data EL represents a light-emitting diode. The entire light-emitting process can be divided into three stages: reset, compensation, and light-emitting. Since the 7T1C driving circuit is a mature technology, the embodiments disclosed herein do not describe the various stages of the light-emitting process in detail. In the light-emitting stage of EL, a portion of the voltage is stored in the parasitic capacitance between the gate and drain of transistor T3, generating a voltage difference ΔVC; when the image changes, ΔVC affects the data voltage V on the drain of transistor T3. Data , thus affecting the capacitance C from transistor T2 to the gate of transistor T3 during the compensation phase st , causing the current to change, and the current formula is as follows:

[0054]

[0055] Where I is the leakage current of transistor T3, that is, the current in EL, μ represents the electron mobility of transistor T3, C ox represents the capacitance coefficient of transistor T3, W represents the channel width of transistor T3, L represents the channel length of transistor T3, V gs represents the gate-source voltage of the transistor T3 , ELVDD represents the first voltage applied to the pixel driving circuit, and ELVSS represents the second voltage applied to the pixel driving circuit.

[0056] When the display screen switches from a black screen with grayscale 0 (its RGB value is (0,0,0)) to a white screen with grayscale 255 (its RGB value is (255,255,255)), the current I1 in EL is expressed as:

[0057]

[0058] When the display screen switches from a 255-grayscale white screen to a 255-grayscale white screen (it can also be understood as a white screen switching to a white screen, or the two adjacent frames displayed are the same, both white screens), the current I2 in EL is expressed as:

[0059]

[0060] wherein, ΔV C1 represents the voltage in the parasitic capacitance between the gate and the drain of the transistor T3 when the display screen displays a black picture, ΔV C2 represents the voltage in the parasitic capacitance between the gate and the drain of the transistor T3 when the display screen displays a white picture before switching, I1 and I2 are equal in an ideal case, but due to the influence of ΔV C , specifically, ΔV C1 > ΔV C2 , which leads to I1 < I2, thus the first-frame brightness decreases when the black picture is switched to the white picture, and temporary image sticking is observed when the image changes (switches). Since ΔV C is different when pictures of different gray scales are displayed, the first-frame brightness decreases to different degrees when pictures of different gray scales are switched. In the related art, the first-frame brightness is usually improved by increasing the complexity of the TFT driving circuit, which not only increases the manufacturing cost, but also may introduce additional failure points, reducing the reliability and stability of the display screen. In the embodiments of the present disclosure, the voltage compensation parameter is used to compensate the data voltage, and the problem of the first-frame brightness decrease caused by ΔV C when the picture switches is compensated.

[0061] Specifically, the embodiments of the present disclosure provide a brightness compensation method, an electronic device, a storage medium and a computer program product, which are described below in conjunction with various specific embodiments. The brightness compensation method can be integrated in a control module of a display panel, which can be a Soc (System on Chip) of the display panel, a DDIC (Dispaly Driver IC), or other control units. The brightness compensation algorithm can be understood as a compensation IP, which compensates the data voltage of the next frame of image to be displayed using the previous frame of image.

[0062] Please refer to Figure 4 , Figure 4 The flowchart of the brightness compensation method provided by the embodiments of the present disclosure is shown in Figure 4 , which includes the following steps:

[0063] In step S110, the gray scale values of a first image frame and a second image frame are obtained, the second image frame is a to-be-displayed image frame, and the first image frame is a previous frame of the to-be-displayed image frame. The gray scale value of the first image frame is denoted as a first gray scale value, and the gray scale value of the second image frame is denoted as a second gray scale value.

[0064] In the embodiments of the present disclosure, the brightness compensation method is used to solve the problem of insufficient brightness when the display panel is switched from the first image frame to the second image frame. The second image frame is denoted as P n , which is the current image frame to be displayed, and the first image frame is denoted as P n-1 , which is the previous image frame of the current image frame to be displayed. Assuming that the video stream in the display panel includes image frames P1, P2, P3,..., P m , if the second image frame P n is P3, the first image frame P n-1 is P2, if the second image frame P n is P4, the first image frame P n-1 is P3, and so on.

[0065] The first image frame and the second image frame each include a plurality of pixels, and each pixel corresponds to an RGB value in the RGB color space. The first image frame and the second image frame can be represented by RGB data. After obtaining the RGB data of the first image frame and the second image frame, the gray values of the first image frame and the second image frame need to be calculated.

[0066] For any pixel, the RGB data of the pixel is represented as (R, G, B), and the gray value corresponding to the pixel is denoted as Gray. The calculation formula of the gray value can be represented as:

[0067]

[0068] In the formula, 2.2 represents the gamma value of the display panel.

[0069] In the embodiments of the present disclosure, when the brightness compensation is performed on the second image frame, the data voltage of each pixel can be compensated independently in units of pixels, or the data voltage of each pixel in the entire image frame can be compensated uniformly. However, when each pixel is compensated independently, the calculation amount and the storage requirement are significantly increased, the resource consumption is large, and the compensation efficiency is low. When the entire image frame is compensated uniformly, the compensation accuracy is low, and the compensation effect is poor. In order to solve the problems existing in the above two compensation methods, in the embodiments of the present disclosure, a block compensation method is adopted. In specific implementation, the second image frame can be divided into a plurality of image blocks, and then each image block is compensated independently.

[0070] Correspondingly, the step of obtaining the gray values of the first image frame and the second image frame comprises: (1) dividing the first image frame into a plurality of first image blocks, calculating the gray value of each first image block as a first sub-gray value, and the set of first sub-gray values of each first image block constitutes the first gray value; (2) dividing the second image frame into a plurality of second image blocks corresponding to the first image blocks one by one, calculating the gray value of each second image block as a second sub-gray value, and the set of second sub-gray values of each second image block constitutes the second gray value.

[0071] For example, the first image frame can be divided into 8 image blocks in a 4*2 division manner, i.e., the first image frame is divided into 4 blocks in the row direction and 2 blocks in the column direction, please refer to Figure 5 , Figure 5 For example, the first image frame can be divided into 8 image blocks in a 4*2 division manner, i.e., the first image frame is divided into 4 blocks in the row direction and 2 blocks in the column direction, please refer to

[0072] Optionally, the step of calculating the gray value of the first image block as a first sub-gray value comprises: (1) calculating the average value of the gray values of each pixel in the first image block; (2) taking the average value as the first sub-gray value corresponding to the first image block. That is, for any first image block, the average value of the gray values of each pixel contained in the first image block is taken as the gray value of the first image block. Wherein, the specific process of dividing the second image frame into a plurality of second image blocks and calculating the second sub-gray value corresponding to each second image block is the same as the calculation process of the first image frame, which will not be described here.

[0073] It can be understood that the division manner and the number of blocks of dividing the image frame are not limited to the exemplary 4*2 division manner, but can be set according to the fineness of brightness compensation, the amount of calculation and the storage requirement, so as to realize the balance between compensation accuracy and compensation efficiency. In addition, dividing the first image frame and the second image frame can also effectively realize the simplification of data processing of any complex display picture, which is beneficial to the IC internal logic algorithm processing.

[0074] In step S120, a voltage compensation parameter corresponding to the first and second gray scale values is looked up from a pre-stored look-up table according to the first and second gray scale values. The look-up table includes a plurality of voltage compensation parameters, each of which corresponds to a third gray scale value and a fourth gray scale value. The voltage compensation parameter represents a compensation parameter that satisfies a first-frame brightness ratio greater than a preset value when the display panel is switched from a display picture of the third gray scale value to a display picture of the fourth gray scale value.

[0075] In the embodiments of the present disclosure, the first-frame brightness ratio can be used to represent the degree of brightness reduction of the first frame of display picture after picture switching. The greater the first-frame brightness ratio, the greater the first-frame brightness after picture switching, and the smaller the degree of first-frame brightness reduction. At this time, the previous frame image is less residual, and the first-frame ghosting phenomenon is less obvious. At this time, a smooth visual experience can be provided. Conversely, the smaller the first-frame brightness ratio, the lower the first-frame brightness after picture switching, and the greater the degree of first-frame brightness reduction. At this time, the previous frame image is more residual, and has obvious dynamic blur and motion ghosting, and the visual experience is poor. The embodiments of the present disclosure compensate the second image frame, that is, increase the first-frame brightness ratio after picture switching.

[0076] In the embodiments of the present disclosure, a look-up table (LUT) is pre-measured and stored. The LUT stores voltage compensation parameters that can satisfy a first-frame brightness ratio greater than a preset value when the display panel is switched from a display picture of one gray scale value to a display picture of another gray scale value. The preset value can be, for example, 85%, 90%, 92%, etc. The voltage compensation parameter is obtained by actually measuring the display panel.

[0077] Suppose that the gray scale value of the display picture before switching in the LUT is denoted as a third gray scale value, and the gray scale value of the display picture after switching is denoted as a fourth gray scale value. The voltage compensation parameter corresponds to one third gray scale value and one fourth gray scale value, and refers to a voltage compensation parameter for compensating the data voltage of the display picture of the fourth gray scale value when the display picture of the third gray scale value is switched to the display picture of the fourth gray scale value. Please refer to Table 1, which is a schematic diagram of the LUT.

[0078] Table 1 LUT

[0079]

[0080] In Table 1, P m represents the image frame after switching, P m-1The third gray value and the fourth gray value before switching are represented by G0, G32, G64, G192, G224, G255, and the like, wherein G0 represents a gray value of 0, G32 represents a gray value of 32, G64 represents a gray value of 64, and so on, and G255 represents a gray value of 255. In Table 1, R_Offset01 represents a voltage compensation parameter when a picture with a gray value of 32 is switched to a picture with a gray value of 0. Similarly, R_Offset10 represents a voltage compensation parameter when a picture with a gray value of 0 is switched to a picture with a gray value of 32. Other voltage compensation parameters represent the same meaning. NA represents a voltage compensation parameter of 0, that is, if the gray values before and after switching are the same, no compensation is needed.

[0081] Optionally, the step of searching, according to the first gray value and the second gray value, the voltage compensation parameter corresponding to the first gray value and the second gray value from the pre-stored lookup table comprises:

[0082] (1) searching, from the pre-stored lookup table, a third gray value closest to the first gray value and a fourth gray value closest to the second gray value;

[0083] (2) taking the voltage compensation parameter corresponding to the third gray value and the fourth gray value as the voltage compensation parameter corresponding to the first gray value and the second gray value.

[0084] In the embodiments of the present disclosure, in order to simplify the operation amount of the brightness compensation method, the third gray value and the fourth gray value in the LUT table are discontinuous values selected from 0-255 gray scales. When searching the voltage compensation parameter from the LUT table, the closest gray scale is selected, that is, the gray scale closest to the first gray value and the second gray value, wherein the closest means that the difference between the gray values is the smallest. For example, the first gray value of the first image frame is 20, and the second gray value of the second image frame is 62. The third gray value closest to the first gray value is 32, and the fourth gray value closest to the second gray value is 64 in the LUT table. The voltage compensation parameter is R_Offset21. It can be understood that the LUT table shown in Table 1 can be increased with more gray scales according to the compensation accuracy.

[0085] In step S130, the data voltage of the second image frame is obtained, the data voltage is compensated by the voltage compensation parameter, and the compensated data voltage is used to drive the display panel to display the second image frame.

[0086] In the embodiments of the present disclosure, the data voltage V Data, i.e. the data voltage, which can also be understood as the source voltage, is determined by the display content, for example, for the second image frame represented by RGB data, for any pixel, the data voltage V Data is determined by the RGB value of the pixel, and the corresponding data voltage V Data can be obtained according to the RGB value of the pixel. Specifically, when the RGB data of the second image frame P n is obtained, the data voltage V n corresponding to each pixel of the second image frame P Data can be obtained according to the RGB data.

[0087] In a possible implementation, the voltage compensation parameter is a voltage compensation value; and the compensation of the data voltage by using the voltage compensation parameter includes: taking the sum of the voltage compensation value and the data voltage as the compensated data voltage.

[0088] Suppose that the voltage compensation value obtained by looking up the table according to the first image frame P n-1 and the second image frame P n is denoted as ΔV T(n-1) , and the data voltage of each pixel in the second image frame P n is denoted as V Data(n) , then the data voltage of each pixel after the compensation of the second image frame P n by using the voltage compensation parameter ΔV T(n-1) is denoted as V Data(n) + ΔV T(n-1) . At this time, the current corresponding to each pixel is denoted as:

[0089]

[0090] In other implementations, the voltage compensation parameter is a voltage compensation coefficient; and the compensation of the data voltage by using the voltage compensation parameter includes: taking the product of the voltage compensation coefficient and the data voltage as the compensated data voltage.

[0091] Suppose that the voltage compensation coefficient obtained by looking up the table according to the first image frame P n-1 and the second image frame P n is denoted as K T(n-1) , and the data voltage of each pixel in the second image frame P n is denoted as V Data(n) , then the data voltage of each pixel after the compensation of the second image frame P n by using the voltage compensation parameter is denoted as K T(n-1) * V Data(n) . At this time, the current corresponding to each pixel is denoted as:

[0092]

[0093] In the embodiments of the present disclosure, the voltage compensation value ΔV T(n-1) , and the voltage compensation coefficient K T(n-1) are used to compensate the first frame brightness reduction problem caused by ΔV C during the picture switching. Ideally, Real ELVDD-(V Data(n) + ΔV T(n-1) ) = ELVDD-V Data(n) - ΔV C , that is, ΔV T(n-1) = - ΔV C ; similarly, ideally, Real ELVDD-K T(n-1) × V Data(n) = ELVDD-V Data(n) - ΔV C , that is, K T(n-1) = (V Data(n) + ΔV C ) / V Data(n) . It can be understood that the voltage compensation parameter can also have other forms of expression, as long as it can inversely compensate the data voltage and eliminate the first frame brightness reduction problem caused by ΔV C during the picture switching.

[0094] Please refer to Figure 7 and Figure 8 , Figure 7 , the display brightness of each frame before and after the switching from G0 picture to G255 picture in the related art, Figure 8 , the display brightness of each frame before and after the switching from G0 picture to G255 picture compensated by the brightness compensation method in the embodiments of the present disclosure, as shown in Figure 7 , without compensation, when switching to G255 white picture, the brightness of the first frame (first frame) white picture and the second frame white picture is lower than the final determined brightness value, and the first frame brightness ratio is about 72%, as shown in Figure 8 , after compensation, after switching to G255 white picture, the brightness of the first frame white picture is close to the final determined brightness value, and the first frame brightness ratio is about 91%, which greatly alleviates the first frame ghosting problem.

[0095] Compared with the related art, the brightness compensation method of the embodiment of the present disclosure pre-measures and stores a lookup table, the lookup table includes a voltage compensation parameter that makes the first frame brightness ratio after switching greater than a preset value when the display panel switches from a picture of a third gray value to a picture of a fourth gray value, when the display panel performs picture switching, the voltage compensation parameter is looked up by using the gray value of the to-be-displayed image frame and the previous frame of the to-be-displayed image frame, and the data voltage of the to-be-displayed image frame is compensated by using the found voltage compensation parameter, so that the problem of first frame brightness reduction caused by IR Drop when picture switching can be compensated, the FFR performance can be improved, the first frame brightness ratio of the to-be-displayed image frame after switching is greater than the preset value, so that the first frame ghosting phenomenon is alleviated, the image sticking problem caused by the residual of the previous frame image is reduced, and the compensation algorithm can be quickly implemented into the driving chip of different display panels without increasing the complex TFT driving circuit, the original driving circuit can be avoided to be modified, the reliability and stability of the display screen can be improved, the implementation is simple, practical, low in cost, and high in feasibility.

[0096] The brightness compensation method of the embodiment of the present disclosure obtains data of a first image frame P n-1 , processes the first image frame P n-1 , calculates a first gray value corresponding to the first image frame P n-1 , obtains data of a second image frame P n-1 in the gap of processing the first image frame P n , calculates a second gray value of the second image frame P n , that is, processes the first image frame P n-1 and processes the second image frame P n , and there is an intersection in time sequence, so that the delay can be reduced. Wherein, processing the first image frame P n-1 and processing the second image frame P n , there is an intersection in time sequence, which can also be understood as: while reading the to-be-displayed image frame, that is, reading the image data of the second image frame P n , the first image frame P n-1 is calculated to calculate its gray value, so as to reduce the delay of the second image frame P n .

[0097] Wherein, for the image frame to be displayed, when the IR Drop inverse compensation is performed, the previous frame image is needed to be used to read the previous frame image for compensation, which can improve the inverse compensation operation efficiency and reduce the delay. Specifically, for the display panel, the current flowing through each pixel will change with the display picture, specifically, the current when displaying a black picture is smaller than that when displaying a white picture, therefore, the IR Drop when displaying a black picture is weaker than that when displaying a white picture, and since the operation of the black picture is simpler and faster, the algorithm operation time for compensating the IR Drop of the black picture is also small.

[0098] Please refer to Figure 6 , Figure 6 For the operation time diagram of compensating the IP for different gray scale display pictures, Figure 6 In the diagram, input represents the processing time of the image data input of the Pattern to the compensation IP, output represents the processing time of the compensation IP outputting the image data, and σ represents the processing time of the compensation IP compensating the image data. Figure 6 In the diagram, Pattern 1 represents a black picture, and Pattern 2 and Pattern 3 represent white pictures. Figure 6 It can be seen that the time for the compensation IP to obtain the Pattern 1 image data is 0, the time for the compensation IP to output the Pattern 1 image data is 0, when switching from Pattern 1 to Pattern 2, the time for the compensation IP to input the image data of Pattern 2 is 115, the processing time σ for obtaining the previous frame (i.e. Pattern 1) image data and compensating Pattern 2 using Pattern 1 is 0 (since the operation of the black picture is simpler and faster), and the time for the compensation IP to output the image data of Pattern 2 is 115; when switching from Pattern 2 to Pattern 3, the time for the compensation IP to input the image data of Pattern 3 is 115, the processing time σ for obtaining the previous frame (i.e. Pattern 2) image data and compensating Pattern 3 using Pattern 2 is 25, and the time for the compensation IP to output the image data of Pattern 3 is 140. It should be noted that, Figure 6 In the diagram, the specific values of input, output and σ are only for expressing the length of the processing time of different Patterns, and do not represent the actual processing time. Figure 6 It can be seen that the operation time for compensating the IR Drop of the black picture is smaller than that for compensating the IR Drop of the white picture.

[0099] The embodiments of the present disclosure compensate the data voltage of the second image frame by the first image frame, can realize dynamic adjustment of the data voltage of the second image frame, and can offset the change of Real ELVDD through dynamic compensation of the data voltage V Data , that is, implement IR Drop inverse compensation, so that the brightness of each pixel point can be quickly and accurately adjusted when the display content changes rapidly.

[0100] Optionally, when the compensation is performed in the block compensation manner, the voltage compensation parameters of the pixels in any second image block are the same. Specifically, when the second image frame is compensated in the block compensation manner, the step of searching the voltage compensation parameters corresponding to the first gray value and the second gray value from the pre-stored lookup table according to the first gray value and the second gray value comprises: for any first image block and the corresponding second image block, searching the voltage compensation parameters corresponding to the first sub-gray value and the second sub-gray value from the lookup table according to the first sub-gray value corresponding to the first image block and the second sub-gray value corresponding to the second image block.

[0101] Correspondingly, the step of obtaining the data voltage of the second image frame, compensating the data voltage by the voltage compensation parameter, and driving the display panel to display the second image frame by using the compensated data voltage comprises: for any second image block, obtaining the data voltage of the second image block, and compensating the data voltage of the second image block by the searched voltage compensation parameter corresponding to the second image block.

[0102] Optionally, the brightness compensation method in the embodiments of the present disclosure further comprises: establishing a lookup table. Wherein, the step of establishing the lookup table comprises: Figure 9 as shown in the figure, comprising:

[0103] In step S210, the voltage compensation parameter of the first frame brightness ratio greater than a preset value when the display panel is switched from the first test picture to the second test picture is obtained, the gray value of the first test picture is the third gray value, the gray value of the second test picture is the fourth gray value, and the third gray value, the fourth gray value and the voltage compensation parameter constitute a group of reference data.

[0104] In step S220, a plurality of groups of reference data are obtained, and a lookup table is established according to the plurality of groups of reference data, wherein the third gray value corresponding to each group of reference data is different and / or the fourth gray value corresponding to each group of reference data is different.

[0105] Wherein, the lookup table is obtained by actually measuring the display panel, for example, for the LUT table shown in Table 1, the first test picture is P m-1 , and the second test picture is P mA set of reference data is a voltage compensation parameter in Table 1 and the third and fourth gray values corresponding to the voltage compensation parameter. Multiple sets of reference data obtained through multiple tests can obtain voltage compensation parameters when a picture of different gray levels is switched to another picture of different gray levels.

[0106] Optionally, the second test picture P m includes multiple frames, and the display panel is acquired to display the first test picture P m-1 switched to the second test picture P m , and the voltage compensation parameter with the first frame brightness ratio greater than the preset value includes the following steps:

[0107] (1) Set multiple voltage compensation parameters R_Offset;

[0108] (2) For any voltage compensation parameter R_Offset, the brightness of the display panel when displaying the first test picture P m-1 is acquired as the original brightness L0, the brightness when displaying the first frame of the second test picture P m is acquired as the first brightness L1, the brightness when displaying the second frame of the second test picture is acquired as the second brightness L2, and the first frame brightness ratio FFR corresponding to the voltage compensation parameter R_Offset is calculated according to the original brightness L0, the first brightness L1, and the second brightness L1. For example, FFR = (L1-L0) / (L2-L0).

[0109] (3) The voltage compensation parameter with the first frame brightness ratio greater than the preset value is obtained from the first frame brightness ratios corresponding to the multiple voltage compensation parameters.

[0110] In the embodiments of the present disclosure, the second test picture P m includes at least two frames, which are respectively denoted as the first frame of the second test picture P m1 and the second frame of the second test picture P m2 , and the gray values of the first frame of the second test picture P m1 and the second frame of the second test picture P m2 are the same. When the first test picture P m-1 is switched to the second test picture P m , the first frame of the second test picture P m1 is displayed first, and then the second frame of the second test picture P m2 is displayed. If the display brightness L1 when displaying the first frame of the second test picture P m1 is the same as the display brightness L2 when displaying the second frame of the second test picture P m2 , it is the best state, and it can be considered that the first frame brightness ratio FFR is 100%, and there is no first frame ghosting at this time. However, since ΔV CThe FFR is usually small, for example, 60%, 70%, etc. In the embodiment of the present disclosure, a plurality of different voltage compensation parameters are set, and the first frame brightness ratio FFR of the display panel when each voltage compensation parameter is used to switch the picture is measured. The voltage compensation parameter when the first frame brightness ratio is greater than a preset value is used as the final determined voltage compensation parameter to construct the LUT table.

[0111] In a possible implementation, the display brightness of the display panel is related to the display content and the display brightness level currently set by the display panel. For example, the minimum display brightness of the display panel is 0, and the maximum display brightness is L max . The display brightness interval of the display panel is represented as 【0, L max 】. The display brightness interval can be divided into a plurality of subintervals in advance, and each subinterval corresponds to a brightness level. The user can set the required brightness level according to the requirement. For any picture, the current is different when the picture is displayed at different brightness levels, and the generated ΔV C is also different, and thus the required voltage compensation parameter is also different. In order to achieve a better FFR compensation effect at different brightness levels, the lookup table in the embodiment of the present disclosure includes a plurality of subtables, and each subtable corresponds to a brightness level.

[0112] Correspondingly, the step of searching, according to the first and second gray values, the voltage compensation parameter corresponding to the first and second gray values from the pre-stored lookup table includes:

[0113] (1) obtaining the brightness level currently set by the display panel as a first brightness level;

[0114] (2) searching, according to the first and second gray values, the voltage compensation parameter corresponding to the first and second gray values from the subtable corresponding to the first brightness level.

[0115] Based on the same inventive concept, the second aspect of the present disclosure provides an electronic device including a memory, a processor, and a program stored in the memory and executable on the processor. The processor is configured to read the program in the memory to implement the steps of the brightness compensation method.

[0116] Based on the same inventive concept, the third aspect of the present disclosure provides a computer readable storage medium, having stored thereon a computer program, which, when executed by a processor, implements the steps of the brightness compensation method as described above. In a specific implementation process, the computer storage medium can include: a universal serial bus flash drive (USB, Universal Serial Bus Flash Drive), a mobile hard disk, a read-only memory (ROM, Read Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various storage media that can store program codes.

[0117] Based on the same inventive concept, the fourth aspect of the present disclosure provides a computer program product, comprising a computer program, which, when executed by a processor, implements the steps of the brightness compensation method as described above. Since the principle of the above-mentioned computer program solves the problem is similar to the principle of the brightness compensation method, the implementation of the above-mentioned computer program can refer to the implementation of the brightness compensation method, and the repeated parts will not be described again.

[0118] The computer program product can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium may, for example, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or component, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: electrical connections with one or more conductive wires, portable disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above.

[0119] Among them, the display module in the embodiment of the present disclosure can be an organic light-emitting diode (OLED) display module. It can be understood that the display module can also be set to other types according to actual needs, for example, the display module can also be a quantum dot light-emitting diode (QLED) display module or a micro light-emitting diode (Micro LED) display module, etc.

[0120] Obviously, the above embodiments of the present disclosure are merely examples for clearly illustrating the present disclosure, and are not intended to limit the implementation manners of the present disclosure. Based on the above description, other different forms of changes or variations can be made by those skilled in the art, and here, all the implementation manners cannot be enumerated, and any changes or variations that are derived from the technical solutions of the present disclosure and are obvious to those skilled in the art are still within the protection scope of the present disclosure.

Claims

1. A brightness compensation method, characterized in that: The following steps are involved: Obtaining grayscale values ​​of a first image frame and a second image frame, where the second image frame is an image frame to be displayed, the first image frame is a frame preceding the image frame to be displayed, the grayscale value of the first image frame is recorded as a first grayscale value, and the grayscale value of the second image frame is recorded as a second grayscale value; searching, based on the first grayscale value and the second grayscale value, a pre-stored lookup table for a voltage compensation parameter corresponding to the first grayscale value and the second grayscale value, the lookup table including a plurality of voltage compensation parameters, each voltage compensation parameter corresponding to a third grayscale value and a fourth grayscale value, the voltage compensation parameter representing a compensation parameter satisfying that a first-frame brightness ratio is greater than a preset value when the display panel switches from displaying an image with the third grayscale value to displaying an image with the fourth grayscale value; A data voltage of the second image frame is acquired, the data voltage is compensated according to the voltage compensation parameter, and the display panel is driven by the compensated data voltage to display the second image frame.

2. The brightness compensation method according to claim 1, wherein: The voltage compensation parameter is a voltage compensation value; and compensating the data voltage by using the voltage compensation parameter includes: The sum of the voltage compensation value and the data voltage is used as the compensated data voltage.

3. The brightness compensation method according to claim 1, wherein: The voltage compensation parameter is a voltage compensation coefficient; and compensating the data voltage using the voltage compensation parameter includes: The product of the voltage compensation coefficient and the data voltage is used as the compensated data voltage.

4. The brightness compensation method according to any one of claims 1 to 3, characterized in that: The brightness compensation method further includes: Obtaining a voltage compensation parameter when the display panel switches from a first test picture to a second test picture and the first frame brightness ratio is greater than a preset value, wherein the grayscale value of the first test picture is the third grayscale value, the grayscale value of the second test picture is the fourth grayscale value, and the third grayscale value, the fourth grayscale value, and the voltage compensation parameter constitute a set of reference data; A plurality of groups of reference data are obtained, and a lookup table is established according to the plurality of groups of reference data, wherein the third grayscale value corresponding to each group of reference data is different and / or the fourth grayscale value corresponding to each group of reference data is different.

5. The brightness compensation method according to claim 4, characterized in that: The second test picture includes multiple frames, and the step of obtaining a voltage compensation parameter when the display panel switches from the first test picture to the second test picture and the brightness ratio of the first frame is greater than a preset value includes: Set multiple voltage compensation parameters; For any voltage compensation parameter, obtain the brightness of the display panel when displaying the first test screen as the original brightness, the brightness when displaying the first frame of the second test screen as the first brightness, and the brightness when displaying the second frame of the second test screen as the second brightness, and calculate the first frame brightness ratio corresponding to the voltage compensation parameter according to the original brightness, the first brightness, and the second brightness; A voltage compensation parameter whose first frame brightness ratio is greater than a preset value is obtained from first frame brightness ratios corresponding to multiple voltage compensation parameters.

6. The brightness compensation method according to claim 1, wherein: The step of searching a pre-stored lookup table for voltage compensation parameters corresponding to the first grayscale value and the second grayscale value according to the first grayscale value and the second grayscale value comprises: Searching a pre-stored lookup table for a third grayscale value that is closest to the first grayscale value and a fourth grayscale value that is closest to the second grayscale value; The voltage compensation parameters corresponding to the third grayscale value and the fourth grayscale value found are used as the voltage compensation parameters corresponding to the first grayscale value and the second grayscale value.

7. The brightness compensation method according to claim 1, wherein: The lookup table includes a plurality of sub-tables, each sub-table corresponding to a brightness level; and the step of searching the pre-stored lookup table for voltage compensation parameters corresponding to the first grayscale value and the second grayscale value according to the first grayscale value and the second grayscale value comprises: Obtaining a currently set brightness level of the display panel as a first brightness level; According to the first grayscale value and the second grayscale value, voltage compensation parameters corresponding to the first grayscale value and the second grayscale value are searched from the subtable corresponding to the first brightness level.

8. The brightness compensation method according to claim 1, wherein: The step of obtaining the grayscale values ​​of the first image frame and the second image frame includes: Dividing the first image frame into multiple first image blocks, calculating grayscale values ​​of the first image blocks as first sub-grayscale values, and a set of the first sub-grayscale values ​​of the first image blocks constitutes the first grayscale value; Dividing the second image frame into blocks to obtain second image blocks corresponding one-to-one to the first image blocks, calculating grayscale values ​​of the second image blocks as second sub-grayscale values, and a set of the second sub-grayscale values ​​of the second image blocks constitutes the second grayscale value; The step of searching a pre-stored lookup table for voltage compensation parameters corresponding to the first grayscale value and the second grayscale value according to the first grayscale value and the second grayscale value comprises: For any first image block and corresponding second image block, voltage compensation parameters corresponding to the first sub-grayscale value and the second sub-grayscale value are searched from the lookup table according to the first sub-grayscale value corresponding to the first image block and the second sub-grayscale value corresponding to the second image block.

9. The brightness compensation method according to claim 8, wherein: The step of calculating the grayscale value of the first image block as the first sub-grayscale value includes: Calculating an average value of the grayscale values ​​of each pixel in the first image block; The average value is used as the first sub-grayscale value corresponding to the first image block.

10. An electronic device comprising a memory, a processor, and a program stored in the memory and executable on the processor, wherein: The processor is configured to read a program in a memory to implement the steps of the brightness compensation method according to any one of claims 1 to 9.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the brightness compensation method according to any one of claims 1 to 9 are implemented.

12. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the brightness compensation method according to any one of claims 1 to 9 are implemented.

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